Astronomy

[Dreamwoven]

Mammutus clouds (http://earthsky.org/earth/amazing-photos-of-mammatus-clouds?utm_source=EarthSky+News&utm_campaign=71e61f9a11-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-71e61f9a11-394044013) from EarthSky

[YesNo]

They look like cotton balls in the sky.

[Dreamwoven]

It seems that the distinction between asteroids and comets in the asteroid belt might be becoming blurred: http://astronomynow.com/2014/11/11/active-main-belt-asteroid-62412-2000-sy178-develops-a-tail/

[YesNo]

The more information one gets the more original categories break down. Ceres could even be a dwarf planet.

[Dreamwoven]

There is a wikipedia page on him (https://en.wikipedia.org/wiki/John_Koethe). He does look interesting. This one on music of the spheres (http://poetrywalks.blogspot.se/2011/08/music-of-spheres.html) is a blog devoted to the subject.

[Dreamwoven]

For Americans, some of you you probably know there is a Planetary Society (http://www.planetary.org). I got it from earth sky.org (http://earthsky.org/space/planetary-society-to-test-its-lightsail-solar-sail-in-may?utm_source=EarthSky+News&utm_campaign=05962b6665-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-05962b6665-394044013). Has its own website and with its own cubesats and solar sail satellite.

[Dreamwoven]

The growing number of space telescopes is beginning to give new information on distant galaxies. See the WISE (http://www.nasa.gov/mission_pages/WISE/main/index.html) and the Spitzer,and the most luminous galaxy (http://www.nasa.gov/press-release/nasas-wise-spacecraft-discovers-most-luminous-galaxy-in-universe).

[Dreamwoven]

Kelvin Helmhotz clouds – also called billow clouds – form when two different layers of air in our atmosphere are moving at different speeds. This come from earth sky.org (http://earthsky.org/earth/kelvin-helmholzt-clouds?utm_source=EarthSky%20News&utm_campaign=7a3c4c6499-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-7a3c4c6499-394044013), showing several variations. Saturn and Jupiter have them as well.

[Dreamwoven]

Two tiny 'CubeSats' will watch 2016 Mars landing (http://www.space.com/29489-marco-cubesats-mars-landing-2016.html?cmpid=NL_SP_weekly_2015-05-27).

A CubeSat is a miniaturised satellite (https://en.wikipedia.org/wiki/CubeSat).

[Dreamwoven]

There is an interesting astronomy blog by Colin Johnson of Armagh Planetarium I have started to follow: http://www.armaghplanet.com. There is post on NASA space drive experiments (http://www.armaghplanet.com/blog/nasas-space-drive-experiments-the-plot-thickens.html). Draw your own conclusions...

[YesNo]

The CubeSat idea is interesting at a cost of about $130,000. I wonder what people will think of using them to do.

I don't understand the "quantum vacuum virtual plasma" in the last link, but the name sounds good.

I understand that Dawn will enter its second mapping orbit on June 9th. Maybe in June the mystery of those bright spots will be resolved.

[Dreamwoven]

A first look (http://www.space.com/17933-nasa-television-webcasts-live-space-tv.html?cmpid=NL_SP_weekly_2015-06-03) at Pluto's weird moons.

[YesNo]

That link seems to be about a new technique for a Mars landing. Just glancing around, it looks like Nix and Hydra have very ellipsoid shapes which may be caused by orbiting a binary system.

[Dreamwoven]

Yes, it is possible. Adding that the Pluto system is so far from the sun that gravity is weakened. We should learn more as New Horizons get closer to Pluto.

[YesNo]

I realize I haven't been looking at the night sky. I should be able to see Sagittarius and Jupiter and Venus should be close together around Cancer.

[Dreamwoven]

We don't get much of a night sky at at our latitude in the middle of summer. I was awake last night and it never got properly dark...

[YesNo]

I noticed that there wasn't much darkness here as well. Yesterday it rained and last night was cloudy, so I didn't see much. I was able to see either Venus or Jupiter the evening before. Then I got distracted and forgot to look when it was darker.

[Dreamwoven]

what latitude are you at? We are at 61 north, only 5 degrees south of the polar circle.

[YesNo]

Chicago is around 40 north. I should be able to see something if it isn't cloudy.

[YesNo]

The view of Jupiter and Venus in the evening sky is relaxing. They are so bright I can even see them.

There is also a place to vote on what you think those bright spots on Ceres are: http://www.jpl.nasa.gov/dawn/world_ceres/# I picked "Other" along with 40% of the others who answered the pole, "Ice" coming in second place with 30% of the vote.

[Dreamwoven]

I agree, the dazzling white blotches on Ceres are not likely to be ice, it does not even look like ice.

All star-gazing for me will have to wait until autumn when our night-time returns…

There is an item in the website Space (http://www.space.com/29641-multiverses-big-errors-astrophysics.html?cmpid=NL_SP_weekly_2015-06-12) once more raising the possibility of there being an infinite multiple of universes. Or what if the universe is endlessly vast in which there is no big bang? We know now that new stars and so new galaxies are born out of cosmic dust, in nebulae, which throws into doubt the big bang theory of the birth of our universe. It is all too simplistic a view. But now I am into big questions that leave me floundering...

[YesNo]

It looks like the time you can view the stars is almost as limited as mine. In the summer when it is warm, there is too much light. In the winter, when it is dark enough, it is too cold. I have to leave my location to view the Milky Way, although I have seen it in Wisconsin and Indiana, neighboring rural states.

The multiverse does seem to be a consequence of there being a big bang. If the universe had a beginning, and eternity is eternal, there must have been many of these events.

The description of Robert Grosseteste's work linked in the Space article you refer to, http://www.space.com/25301-multiverse-concept-middle-ages-grosseteste.html, makes me think we might be misinterpreting him. The article refers to an "extra reason" Grosseteste had, but I don't know what it was. Today, many think we need a multiverse not just because eternity is eternal and what happened once would happen again, but to get to our universe there must have been a lot of failed universes out there where life could not survive. However, all of these universes may have succeeded in generating life.

I think the big bang is true, because we don't see anything older than 14 billion years in our universe. It is probably more complicated than we are currently aware.

[Dreamwoven]

Thanks for the link YesNo, that was it, the Grosseteste article.

[Dreamwoven]

The plans that are being made for tunnelling probes seem quite fantastic. This article is an example of that: http://www.space.com/29644-cryobot-tunneling-robot-explore-icy-moons.html?cmpid=NL_SP_weekly_2015-06-15

[YesNo]

It amazes me that there is an ocean there under the ice. I would have thought it would be solid ice all the way down.

[Dreamwoven]

We are starting to get more information on Pluto and its moons:

Society for Popular Astronomy [email protected]

TWO CHAOTICALLY TUMBLING PLUTO MOONS

Space Telescope Science Institute (STScI)

A comprehensive analysis of all available Hubble data shows that two of Pluto's moons, Nix and Hydra, are wobbling unpredictably. Scientists believe that the other two small moons, Kerberos and Styx, are probably in a similar situation. Such chaos may arise because the moons are embedded in a dynamically shifting gravitational field caused by the system's two central bodies, Pluto and Charon, orbiting one another. The variable gravitational field induces torques that send the smaller moons tumbling in unpredictable ways. The torques are increased by the fact that the moons are ellipsoidal rather than spherical. Hubble's monitoring of Pluto's four outer moons has also shown that three of them, Nix, Styx, and Hydra, are locked together in a resonance with a precise ratio among their orbital periods. That ties together their motions in a way similar to that of three of Jupiter's large moons. Hubble provides observational evidence that the satellites are also orbiting chaotically. However, that does not necessarily mean that the system is on the brink of flying apart. Astronomers would need to know a lot more about the system before they could determine its long-term fate. Surprisingly, Hubble also found that the moon Kerberos is as dark as charcoal, while the other satellites are as bright as white sand. It was predicted that pollution by dust blasted off the satellites by meteorite impacts should coat all the moons, giving their surfaces a homogeneous look. The New Horizons probe, which will fly by the Pluto-Charon system in July, may help to settle the question of the asphalt-black moon as well as the other oddities uncovered by Hubble. The new discoveries are being used in the planning of the New Horizons observations. The chaos in the Pluto-Charon system may offer insights into how planets orbiting a double star might behave. We are learning that chaos may be a common trait of binary systems, and the Kepler space observatory has found several planetary systems orbiting double stars.

Clues to the Pluto chaos first came when astronomers measured variations in the brightness of the two moons Nix and Hydra, which changed unpredictably. The team analyzed Hubble images of Pluto taken in 2005-2012 and compared the changes in the moons' reflectivity with dynamical models of spinning bodies in complex gravitational fields. Virtually all large moons, as well as small moons in close-in orbits, keep one hemisphere facing their parent planet, as the Moon does to the Earth, so the satellites' rotations are perfectly matched to their orbital periods, as a consequence of gravitational tides between moon and planet. (Hyperion, which orbits Saturn, is the only other Solar System example of chaotic rotation; it is due to the combined gravitational forces of the planet and it largest moon, Titan). Pluto's moons are hypothesized to have formed by a collision between Pluto and another similar-sized body early in the history of the Solar System. Pluto's large companion, Charon, which is almost half the size of Pluto itself, was discovered in 1978. Hubble discovered Nix and Hydra in 2005, Kerberos in 2011, and Styx in 2012. Those little moons, measuring just tens of miles across, were found as part of a search for potential hazards to the New Horizons spacecraft flyby. Pluto and Charon are called a double planet because they orbit about a common centre of gravity that is located in the space between the bodies. Some people regard the Earth--Moon system as a double planet, too, although its centre of gravity falls within the Earth. (Our Moon has 1/80th of the Earth's mass, whereas Charon has 1/8th of Pluto's mass.) A combination of data from Hubble, New Horizons's brief close-up look, and eventually the James Webb space telescope, should lead to increased understanding of the Pluto-Charon system. No ground-based telescope has yet been able to detect the smallest moons.

[YesNo]

It is interesting that the smaller moons of Pluto have only recently been discovered and then mainly as research for New Horizons.

Also the idea that Pluto and Charon may be a "double planet", or probably better put double dwarf planet, is because the center of gravity is outside both Pluto and Charon unlike the Earth-Moon center of gravity which is inside the Earth.

[Dreamwoven]

We know that Saturn's largest moon, Titan (https://en.wikipedia.org/wiki/Lakes_of_Titan), has surface lakes of ethane and methane and there are plans to send a probe to investigate these more closely. Now Jupiter's moon Europa (https://en.wikipedia.org/?title=Europa_(moon)) is also known to have sub-surface oceans (https://en.wikipedia.org/?title=Europa_(moon)#Subsurface_ocean) and there are plans to send a probe there too.

[YesNo]

I haven't seen anything new pop up in searches on Ceres. I was hoping there would at least be closer images.

A couple nights ago, I saw the big dipper while I watched the moon set. I check my vision based on how clearly I can see the moon at night. My astigmatism sometimes gives me many images of the moon, most of them blurry.

[tailor STATELY]

Ceres Google search iso'd to last 1 hour: https://www.google.com/search?q=ceres+news&num=100&newwindow=1&client=opera&hs=QtX&channel=suggest&prmd=ivns&source=lnt&tbs=qdr:h&sa=X&ei=8D2MVcqSAYqqgwS8-pfYCg&ved=0CA8QpwU

Ta ! (short for tarradiddle),
tailor STATELY

[YesNo]

Here's an article about Population III stars, the oldest stars, "unpolluted" by atoms besides hydrogen and helium, that I found by running the query you provided, tailor STATELY: https://medium.com/starts-with-a-bang/have-we-just-found-the-first-stars-in-the-universe-f5385eb4264d

[Dreamwoven]

It is 2 weeks to the historic flyby of the Pluto system. The last planet to visit in a half-century of exploring our solar system. New Horizons will pass at high speed between Pluto and Charon. See EarthSky (http://earthsky.org/space/pluto-charon-new-horizons-flyby-updates-july-2015?utm_source=EarthSky+News&utm_campaign=9fdf3278aa-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-9fdf3278aa-394044013).

[YesNo]

The animation in the video doesn't make it look as if the center of gravity is outside Pluto. I would have expected them to both circle a center outside Pluto.

[Dreamwoven]

NASA and New Horizons show what they term "the wobbly dance" of Pluto and Charon (http://www.space.com/28545-pluto-charon-wobbly-dance-proves-it-s-a-double-planet-video.html). Maybe this is indicative of the centre of gravity being outside Pluto?

[YesNo]

Yes, that one does show the center of gravity outside Pluto. I wonder if we would feel dizzy living on such a planet? Probably not. Perhaps the stars would have a retrograde motion as the outer planets do for us.

[Dreamwoven]

Take a bit of getting used to, I suppose...

[Dreamwoven]

It is now only a week to the flyby of Pluto/Charon and its moons. New Horizons has had its last course adjustment to make it pass between Pluto and Charon.

http://earthsky.org/space/pluto-charon-new-horizons-flyby-updates-july-2015

[YesNo]

The anomaly showed the importance of the robotics on that mission. I wonder why methane was considered important?

Jupiter and Venus are near each other in the night sky. http://www.cnn.com/2015/06/30/us/feat-jupiter-venus-conjunction/index.html

[Dreamwoven]

I think methane is important as indicating the possibility of extra-terrestrial life: http://www.space.com/29674-mars-meteorites-methane-life-search.html

[YesNo]

Yes, that makes sense. On dwarf planets like Pluto it may be a liquid to support life in place of water.

[Dreamwoven]

In the coming week we will be getting better images of Pluto and Charon. This one from earth sky.com (http://earthsky.org/space/pluto-charon-new-horizons-flyby-updates-july-2015?utm_source=EarthSky+News&utm_campaign=9b68061c96-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-9b68061c96-394044013) is the latest. I have often wondered what kind of images we can expect from New Horizons and I wondered how, if the probe passes between Pluto and Charon at tremendous speed, this will be done?

The answer lies in the New Horizons’ Long Range Reconnaissance Imager (LORRI). There is an article on it in Wikipedia (https://en.wikipedia.org/wiki/New_Horizons#Science_payload), and more information at this site: http://arxiv.org/pdf/0709.4278.pdf.

[YesNo]

The "whale" and "donut" are interesting formations on Pluto along with those spots. I was thinking as well that there may not be enough time to explore Pluto with just a fly-by.

[tailor STATELY]

Update Pluto:

http://www.space.com/29924-pluto-larger-than-thought-nasa-flyby.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+spaceheadlines+%28SPACE.com+H eadline+Feed%29&utm_content=FeedBurner

Ta ! (short for tarradiddle),
tailor STATELY

[YesNo]

I'm surprised they didn't have the size correct before. At least in this video the new size has an estimate of the error with it.

[Dreamwoven]

The New Horizons probe is now well past Pluto and heading further into the Kuiper Belt, where it is planned to study at least two other objects. We have not seen most of the data from the Pluto/Charon Flyby, it is still being sent back but by the much slower link. It will be coming in the next couple of months. The only other object to be snapped is one of Pluto's tiny moons, Nix: perhaps other moons will follow? You can see the images here (http://www.space.com/29983-pluto-moon-nix-first-images.html?cmpid=NL_SP_weekly_2015-07-20), just 25 miles in diameter and here for further images of Pluto-Charon (http://www.space.com/29988-new-horizons-pluto-probe-future.html?cmpid=NL_SP_weekly_2015-07-20).

[YesNo]

It is interesting that the funding to go to those other two KBO objects has not yet be obtained.

[Dreamwoven]

New Horizons has shot off on its projected route. There is little else for it to do, as it can't stop and turn around. They even have some fuel left to slightly change course should that be needed. This has been planned for quite some time, I don't think they need funding. Perhaps they hope that Kuiper Belt objects they are going to fly past will provide reason to send another probe there.

[YesNo]

I think the additional funding would be for the staff on earth, however, I don't see why it should cost much more just to get the data even if no one analyzes it. It would be years from now anyway before New Horizons reaches those objects.

[Dreamwoven]

NASA funds specific projects as specified in the grant application. The New Horizons project must have been funded well before launch (just some 10 years ago). There are already some detailed images of Pluto arriving (see 21 July image of Pluto's mountains (http://www.space.com/30002-pluto-heart-has-second-mountain-range.html?li_source=pm&li_medium=most-popular&li_campaign=related_test)).

[YesNo]

Pluto has fleshed out more in my imagination since that flyby mission. It is interesting that they did not build a better data transmission technology since it will take a year to get the full data back.

[Dreamwoven]

I agree with you, YesNo. Information is coming in dribs and drabs, and will continue to do so for the next 18 months.

Here is an item from EarthSky (http://earthsky.org/space/latest-images-of-plutos-flowing-ice?utm_source=EarthSky+News&utm_campaign=2775938f2f-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-2775938f2f-394044013) image with evidence of what looks like flowing ice on Pluto.

[Dreamwoven]

The closest exoplanet yet to be found is is just 21 light years away. it can be read about here: http://www.rt.com/news/311233-exoplanet-new-nasa-earth/. We may now be entering a new phase in space exploration using large telescopes launched into space.

[YesNo]

I also liked this link contained in the one you mentioned about finding a planet similar to earth circling another star: http://www.rt.com/news/310612-space-habitable-planet-nasa/

It has been 20 years since the first evidence of exoplanets was found.

[Dreamwoven]

Cassini is still operating around Saturn, it seems. This post shows that red arcs are visible on one of its larger moons, Tethys, that no-one is able to explain: http://www.space.com/30149-saturn-moon-tethys-weird-red-arcs.html?cmpid=NL_SP_weekly_2015-08-05

[YesNo]

Those red markings on Tethys are as unusual as those bright spots on Ceres.

[Dreamwoven]

This year will be very favourable for the annual Perseid meteors, with virtually no moonlight to spoil the view – weather permitting, of course! The peak of activity for the UK is expected this coming Wednesday night, 12–13 August, with the actual peak being predicted at 07h on the Thursday morning.
However, says Meteor Section Director Tony Markham, good rates are also likely during the nights of Aug 11–12 and 13–14, so don't just focus on the night of Aug 12–13 and risk it being clouded out.
While other predicted showers may have higher rates, the comparatively mild evenings at this time of year make the Perseids a favourite. And unlike most other types of observing, you need virtually no equipment other than your eyes. Just lie down comfortably on a lounger or similar, gazing up at as much of the sky as you can manage, out of the line of sight of any bright lights. Don’t forget a blanket – it can still get chilly in August!

[YesNo]

I'm going to have to make sure I'm out looking for them later this week.

[YesNo]

I saw a really bright shooting star last night while looking for the Perseid meteor showers. That one and the one I saw the night before last while trying to scout out the sky to find out where the Perseus constellation was are the only two that I saw. I noticed that the Andromeda galaxy is not far away, but the light was too bright where I live even with binoculars to locate it clearly. Also the sprinkler system for the lawn turned on and so I stopped.

[Dreamwoven]

The Perseides are meant to be especially visible at that time. I didn't get to see any. This idea for an inflatable space elevator (http://www.space.com/30272-space-elevator-inflatable-concept-patent.html?cmpid=NL_SP_weekly_2015-08-17) is amazing. It just got funding to develop.

[YesNo]

So they raise and lower this 12 mile high tower to reduce the initial liftoff costs. That is an amazing idea.

[Dreamwoven]

Well, its a private venture, and this was just an application for funding. I guess we will see :)

[Dreamwoven]

This post in Space discusses two project to visit Saturn's moon Enceladus (http://www.space.com/30419-alien-life-search-enceladus-mission.html?cmpid=NL_SP_weekly_2015-08-31) to search for life. The post is quite detailed and worth reading,though it will only be in the mid-2020s that they will happen.

[YesNo]

Being able to go through the plumes coming out of Enceladus without landing looks promising. Also using solar power for the mission should help expand our reach without using more expensive fuels.

[YesNo]

I spent last week in Wisconsin along Green Bay in a cottage facing north-west and a picture window over the bay. The nights were mostly clear and I was able to watch the dippers and draco move around the north star and early in the morning watch Vega sink to the horizon while the swan and Hercules majestically came into view and pass into the dawn. At times there were shooting stars and I think I even saw satellites moving across the sky. Of course there was the Milky Way. Binoculars showed many more stars pointing in that direction than elsewhere.

[Dreamwoven]

Venus came close to the moon at dawn earlier this week and put on a fine display. Brilliant, it was, almost dazzling.

[YesNo]

When I looked out an eastern facing window this morning the first thing I saw was Venus. Not even Chicago's light pollution can stop that from shining brightly.

I wondered if there was any more news about Ceres spots. This Wikipedia article seems to have the most pictures: https://en.wikipedia.org/wiki/Bright_spots_on_Ceres

[Dreamwoven]

It will be a while yet:

"Dawn will fly around Ceres eight times in its current orbit until June 28, when it will begin to spiral closer to the draft planet, heading for a 900-mile (1,450-kilometer) orbit in early August. By the end of the year, Dawn is scheduled to be closest to Ceres at an altitude of 232 miles (373 kilometres)." source: http://spaceflightnow.com/2015/06/10/bright-blobs-on-ceres-ready-for-their-close-up/

[Dreamwoven]

I have been re-reading Immanuel Velikovsky's Earth in Upheaval (http://www.knowledge.co.uk/velikovsky/earth-in-upheaval.htm) which decided me to write a longer post on this work of his. Quite by chance, today on earth sky.com, I found this post about a huge double asteroid impact, some 450 million years ago in Mid-Sweden around Östersund (https://en.wikipedia.org/wiki/Östersund). It has only just been discovered!

[YesNo]

I don't know anything about Velikovsky's theories. Looking forward to the longer post on this.

[YesNo]

Just a report. I saw the blood moon earlier this evening. Unless it is delayed for some reason, the end of the world didn't happen.

[Dreamwoven]

Here is an explanation from earth sky: Total eclipse begins The dark shadow completely covers the moon. This is the total phase of the eclipse, called the totality. It generally lasts for about an hour. During the totality, the shadow on the moon often appears red. It is very beautiful, and the subtle colors change and shift through totality! Plus, red isn’t the only color you’ll see during totality. There are grays and browns, too. Some people say they see a rim of the color turquoise on the moon, in the minutes around the start and end of totality. This turquoise color is the result of absorption by Earth’s ozone layer. The various swaths of color across the moon’s face – especially toward the beginning and ending of totality – create an effect known as the Japanese lantern effect. You can capture it in photos, like the photo above by Monica Hall: http://earthsky.org/space/how-do-i-watch-the-total-lunar-eclipse

[Dreamwoven]

earthsky.com is my favourite space website, the team has a lot of enthusiasm that shows in their work, and it includes everything in and between earth and sky.

[Dreamwoven]

Venus has been dazzlingly bright in the southern sky for much of the second half of September. See this link: http://astronomynow.com/2015/09/17/see-planet-venus-dazzle-at-greatest-brilliancy-in-the-pre-dawn-sky/.

[YesNo]

Yes, I see it in the morning when I get up around 6 am. Venus is unavoidable in the sky (unless one is asleep or it is overcast).

[YesNo]

I woke up early this morning and Venus was bright in the east. It's in the constellation Leo and just below it is Mars (rather dim but visible nonetheless). Then comes Jupiter followed by a beautiful crescent moon. I went outside for a bigger view and those planets are the brightest objects in the sky even beating Orion to the south.

Mercury is supposed to be down there as well, but I couldn't see it because of the buildings. I heard at yoga class on Thursday that Mercury was ending a retrograde period. After looking that up later I found out that Mercury is now "direct", which I suppose means going the way it is supposed to go. For Mercury this occurs three times a year for about 3 weeks. That's astrology rather than astronomy. Here's the Huffington Post on it: http://www.huffingtonpost.com/larry-schwimmer/mercury-retrograde-ends-o_1_b_8264282.html

[Dreamwoven]

You are lucky to have seen those three planets together, Venus, Mars and Jupiter (and the moon). I don't think I've seen them all together before.

[YesNo]

This morning I went to a public park along the west side of Lake Michigan and watched Venus, Mars, Jupiter, Mercury and the crescent moon which was lower today in the sky than Mercury point to where the sun would rise. The park opened at 6 am which gave me plenty of time to observe as much as I wanted. Also the light pollution was lower than where I live.

I tried taking pictures with my phone, but they are not sharp or I would have posted some. I will have to find a way to use the phone to get better night pictures. Also I tried to see Venus clearly enough to see what phase it was in through the 7x50 binoculars, but I couldn't tell.

[Dreamwoven]

I have never seen Mercury (https://en.wikipedia.org/wiki/Mercury_(planet)), it is too small and too near the sun.

Information is still coming in concerning the Pluto-Charon system (https://blogs.nasa.gov/pluto/2015/10/05/plutos-small-moons-nix-and-hydra/), which includes the four small moons that also circle around the system. The centre of gravity of the system is somewhere between the two dwarf planets which dance around each other. It is a very curious system!

This is well explained in the NASA post on this (see the link above). They are so far away from the sun that gravity is weak. New Horizons is now entering the Kuiper Belt (https://en.wikipedia.org/wiki/Kuiper_belt) to examine some of the objects there. So information will be coming in for some years.

[Dreamwoven]

I came across this piece on how the moon is being affected by earth's gravitation, opening up stresses and cracks in its surface: http://www.space.com/30795-earth-gravitational-pull-cracks-moon.html. It seems major changes go on all the time.

[YesNo]

Your link to the Pluto-Charon system led me to the cirumbinary planetary system found a few years ago: http://www.nasa.gov/mission_pages/kepler/news/kepler-47.html#.Vh4xdvmrTIU It would be similar to the four outer moons circling Pluto and Charon.

The idea of "orbital resonance" is also interesting: https://en.wikipedia.org/wiki/Orbital_resonance I don't understand it, but there are around 200 planets with orbital resonance of 2:3 between them and Neptune, including Pluto and its moons, all called "plutinos". "Clearing the neighborhood" I originally thought meant absorbing the objects in a planet's orbit but it may also mean pushing them outward away from it.

[Dreamwoven]

I don't understand orbital resonance either, a bit too complex maths for me I'm afraid. But I get the gist, and can see how this would create strains in the planets so affected, especially in the moon.

[YesNo]

Lately the morning skies have been clear. Mars and Jupiter are close together and Mars has moved further east than Jupiter passing it by. It makes sense that Mars goes faster since it is closer to the Sun. Venus is also moving toward the east based on its position relative to the stars in Leo and I assume months later it will be visible in the evening. It is usually in the evening when I have noticed it in the past.

[Dreamwoven]

This is an interesting post from space.com: http://m.space.com/30832-kepler-telescope-alien-megastructure.html. It is very far away, would take 1,500 years at the speed of light to get there, and another 1,500 years to get back. But still interesting. When we get the larger space-based telescopes, the next generation after the now ageing Kepler, we should learn more, like this one: https://en.wikipedia.org/wiki/Advanced_Technology_Large-Aperture_Space_Telescope. Parked at a Lagrange point (https://en.wikipedia.org/wiki/Lagrangian_point) between sun and earth these larger telescopes may provide much extra information on faraway exoplanets.

[YesNo]

That star KIC 8462852 is interesting. Not only does it have a planet, but it may even have intelligent life. The Kardashev scale, mentioned in the article, to measure the level of civilization was also interesting: https://en.wikipedia.org/wiki/Kardashev_scale

[Dreamwoven]

From Society for Popular Astronomy Newsletter 38, popastro.com:

I had no idea that meteor trails were created by comets, in this case Halley's Comet, on its route round the solar system. Same must apply to all meteor trails, not just those produced by Halley's. There is more about these in the popastro.com post.

Orionid meteors appear
The annual Orionid meteors (shooting stars), which are caused by dust from the tail of Halley's Comet, are upon us. These appear in good numbers between 20 and 23 October, and official rates are given as 20–25 an hour. But that's the number that could be seen under ideal conditions, which never apply in the UK, so actual rates are likely to be somewhat lower. In practice you might see one every ten minutes or so on average, if you are a good, dark location and can see all the sky with clear conditions. And that applies in the early morning hours, so be patient!
These meteors appear to come from the direction of Orion, which rises in the east at about 10 pm BST, so any meteors you see before that time won't be Orionids. Once the radiant (the source point) rises, numbers will increase throughout the early hours. This year, the first-quarter Moon sets at around midnight, or is low in the western part of the sky, so will not make a great difference to observations.
Orionid meteors are typically swift-moving, with long and persistent trains. While there is no particular direction where they will appear, it's best to avoid looking directly at or near Orion itself, as the meteors will appear foreshortened in that direction and won't be as easy to spot. The diagram on the right shows the position of the radiant and how it moves against the starry background during the shower appearance.
Get more information on the Orionids and how to observe them at the SPA Meteor Section site. If you want to contribute, please count the numbers of Orionid and other meteors that you see in an exact period, and send them to the Meteor Section director.

Meteors and comets
Does the appearance of these meteors mean that we might see Halley's Comet as well? Sadly, no. What happens is that the dust from the comet has spread all along the comet's orbit around the Solar System. Halley's Comet is now almost as far away from Earth as it can get, beyond the orbit of Neptune. It has also spread over a wider area than the comet's orbit itself, which is why we see these particles coming through our atmosphere even though Halley's Comet itself can't come very close to the Earth.

See also [URL="http://earthsky.org/earth/asteroid-showers-linked-to-mass-extinctions?"]

[YesNo]

I didn't see any Orionid meteors, but I did notice how Venus is moving faster to the East than Jupiter and is even catching up with Mars.

[Dreamwoven]

The ongoing flyby-reconnaissance of the solar system is coming to an end, with New Horizons speeding on to the kuiper belt and the Cassini decade-long flyby of the moons of Saturn reaching its climax with a dive through the plumes of Enceladus.

It has been a remarkable recce.
See http://earthsky.org/space/new-horizons-pluto-new-target-2014-mu69-maneuvers and
http://earthsky.org/space/does-enceladus-support-life-7-key-facts

The more detailed surveys will have to be like that done on Mars. Still preliminary but most interesting.

[YesNo]

I didn't know Cassini had been out there since 2004. It looks like the final mission will be to run and probably crash through Saturn's rings.

[Dreamwoven]

http://earthsky.org/astronomy-essentials/everything-you-need-to-know-zodiacal-light-or-false-dawn

The false dawn I see on some days (not often) at our location of 61 degrees north is not in the east at all it is in the north, and it is often above the clouds, as a general and vague lightness in the sky, several hours before dawn. I've always assumed it was the aurora borealis I can see, not zodiacal light, a bit like the last but one photo in the earthsky link above. It looks like the loom of the small town of Söderhamn (https://en.wikipedia.org/wiki/S%C3%B6derhamn). But I am still not sure what light it is I am seeing to our north!

Has anyone else experienced something similar?

[YesNo]

It can't be the zodiacal light since that would have to be along the ecliptic. I'm lucky to see stars at all where I am although there have been clear nights.

Does the light change location throughout the year? Does it last all night?

[Dreamwoven]

It doesn't change location, I don't know if it lasts all night, would have to stay up to see it. I've never seen it in the evenings either..

[YesNo]

If it doesn't change location then that suggests to me it is earth based.

[mal4mac]

New game: mention works of literature that include astronomical phenomena and other astronomical matters. I'll start

Northern Lights in Knausgaards's "Dancing in the Dark". (He's also relates how he taught young children basic cosmology.)

[Dreamwoven]

We are on the verge of entering a new era in space exploration.It is quite clear that it will be a long time before humans even go to Mars, never mind Pluto. Space travel will have to wait for the development of telescope development. We are already there with space-based telescopes such as Hubble and Kepler, as well as land-based arrays of telescopes combining their fields with each other. There are now other kinds of telescopes than visual: radio astronomy (https://en.wikipedia.org/wiki/Radio_astronomy) being the current development. There is now a list of telescope types (https://en.wikipedia.org/wiki/List_of_telescope_types). Recently, these telescopes were recently used to find unusual patterns. This post on the 19th October mentions one, observing strange phenomena at a distance of 1,500 light years:

This is an interesting post from space.com: http://m.space.com/30832-kepler-tele...structure.html. It is very far away, would take 1,500 years at the speed of light to get there, and another 1,500 years to get back. But still interesting. When we get the larger space-based telescopes, the next generation after the now ageing Kepler, we should learn more, like this one: https://en.wikipedia.org/wiki/Advanc...pace_Telescope. Parked at a Lagrange point between sun and earth these larger telescopes may provide much extra information on faraway exoplanets.

[YesNo]

I agree that telescopes are more important than human space travel outside the protection of the earth's magnetosphere. I see these telescopes as robots although more controlled than one pictures robots in the movies.

[YesNo]

I suppose there might be some reference to the skies in Ovid's Metamorphoses, mal4mac, but I can't remember any in particular at the moment.

I just finished checking on the positions of Jupiter, Venus and Mars and it looks like Venus and Mars are in a line next to each other. One of the things I've noticed about watching these planets is that their movements are not subtle.

[Dreamwoven]

It seems our own galaxy, the Milky Way, has a mysterious Great Dark Lane (http://www.space.com/31046-milky-way-has-great-dark-lane.html) of dust around it. The link is from Space.com. its origins are unknown, but this is potentially an important discovery.

[YesNo]

I wonder how much this dust removes the need for dark matter.

The crescent moon and Venus were amazing this morning.

Here's a picture:

http://i1136.photobucket.com/albums/n494/Yes-No-Maybe/Moon%20Venus%20Mars%20and%20Jupiter.jpg (http://s1136.photobucket.com/user/Yes-No-Maybe/media/Moon%20Venus%20Mars%20and%20Jupiter.jpg.html)

I took this with my camera without a tripod. Notice the phases of the Moon. I think you can also see the phase of Venus. It isn't pointed in the same direction as the Moon which makes me think it doesn't have to, but then I wonder why not? Mars is very faint just above Venus and Jupiter is at the top. It looks better in real life.

[Dreamwoven]

Interesting that you got the picture of the phases of both Moon and Venus in the same shot.

[Dreamwoven]

This from space.com: http://www.space.com/20930-dark-matter.html (http://www.space.com/20930-dark-matter.html) on Dark Matter is very peculiar. It tries to say what Dark Matter is. Yet it left me confused. Perhaps we don't really know what it is.

[YesNo]

Dark matter is an interesting mystery. This is how I see it based on your link.

Our current laws of gravitation require there to be more matter in the universe than our measurements have accounted for so far. There are three explanations for the discrepancy:

1) Our current laws of gravitation are incorrect.

2) Our measurements of the amount of ordinary, "baryonic" matter are incorrect.

3) There is a new kind of "non-baryonic" matter out there that we can't measure or even detect.

It seems to me that 1 and 2 or some combination of them are more likely, but apparently many scientists favor 3. It seems to me more likely that there exist alien life forms out there that we have not found than that there exists another form of matter, but who knows?

[Dreamwoven]

Yes, it is all very confusing.

[Dreamwoven]

Eric, a recently discovered trans-Neptunian dwarf planet,dubbed Eris, has been discovered. See http://www.space.com/28379-eris-dwarf-planet.html. Its in the kuiper belt and takes some 550 years to make one orbit of the sun. Read about it on the website. Published in January 2015, I must have missed it!

[YesNo]

It is amazing how much we don't know. In the "dwarf planet" link in the link you cite I hear there may be 200 dwarf planets out there. We know of only a handful of them. http://www.space.com/15216-dwarf-planets-facts-solar-system-sdcmp.html

I also ran into a link saying that black holes can't exist: http://phys.org/news/2014-09-black-holes.html For some reason, I thought these had been observed already.

[tailor STATELY]

I thought the conventional theory was that there are observable black holes in the center of all spiral galaxies (including the Milky Way and Andromeda), and that crazy-fast velocity stars have been observed orbiting them ?

Ta ! (short for tarradiddle),
tailor STATELY

[Dreamwoven]

Yes, tailor STATELY, it is the dominant theory, as you say.

I've just read the two links in YesNo's post, and neither of the two theories are any more than that - theories. I've been particularly suspicious of one single big bang theory, it assumes there is only 1 universe and that it is finite:

"Many physicists and astronomers believe that our universe originated from a singularity that began expanding with the Big Bang. However, if singularities do not exist, then physicists have to rethink their ideas of the Big Bang and whether it ever happened, or whether it is unique."

Read more at YesNo's second link: http://phys.org/news/2014-09-black-holes.html#jCp

[tailor STATELY]

I ♥ fizz9, but it makes my brane hurt.

Ta ! (short for tarradiddle),
tailor STATELY

[Dreamwoven]

Yes, tailor STATELY, it is the dominant theory, as you say.

I've just read the two links in YesNo's post, and neither of the two theories are any more than that - theories. I've been particularly suspicious of one single big bang theory, it assumes there is only 1 universe and that it is finite:

"Many physicists and astronomers believe that our universe originated from a singularity that began expanding with the Big Bang. However, if singularities do not exist, then physicists have to rethink their ideas of the Big Bang and whether it ever happened, or whether it is unique."

Read more at YesNo's second link: http://phys.org/news/2014-09-black-holes.html#jCp

The last para in the link is as follows:

"Physicists have been trying to merge these two theories – Einstein's theory of gravity and quantum mechanics – for decades, but this scenario brings these two theories together, into harmony," said Mersini-Houghton. "And that's a big deal."

Read more at: http://phys.org/news/2014-09-black-holes.html#jCp

[tailor STATELY]

Yes I read the article 3 - 4 times. "But for now, Mersini-Houghton says the mathematics are conclusive." - sounds a little dubious. Hope they're right in a way; if not just to push forward from there.

Ta ! (short for tarradiddle),
tailor STATELY

[YesNo]

A lot of it sounds dubious to me as well, but I thought black holes were as established as, say, exoplanets which can be spotted as they make a transit across their suns. It makes me wonder just what the evidence is for black holes.

[Dreamwoven]

There its a long post in Apologetics Press (http://www.apologeticspress.org/apcontent.aspx?category=9&article=1453) on the Big Bang theory and its evolution. Worth reading.

[Emil Miller]

I have little interest in astronomy, nor do I pay much attention to videos about aliens and other juvenile concepts such as those that appear on YouTube where conspiracy theories abound.
There's a lot of uninformed chatter about the moon landings for example and then there's this:

https://youtu.be/tHJUVDL68iw


Edit: with apologies for the juvenile comments that are also a major feature of YouTube.

[YesNo]

There's a lot of uninformed chatter about the moon landings for example and then there's this:

https://youtu.be/tHJUVDL68iw



I find it hard to believe that the Apollo missions to the Moon were manned. I loved the juvenile comments in the video.

Why do we need to send humans that far into space anyway? Isn't that what "artificial intelligent" robots are for? I suppose if we put advanced telescopes at a Lagrangian point which would be further than the Moon, we may need to have a human be able to make repairs.


There its a long post in Apologetics Press (http://www.apologeticspress.org/apcontent.aspx?category=9&article=1453) on the Big Bang theory and its evolution. Worth reading.

Much of this is confirmed by Peter Coles' "Cosmology A Very Short Introduction" that I am also reading to get an overview. I liked this Berlinski quote from the link:


Contemporary cosmologists feel free to say anything that pops into their heads.

[Dreamwoven]

Why do we need to send humans that far into space anyway? Isn't that what "artificial intelligent" robots are for?

I agree with this (and Emil). All the dithering over 'going to Mars' is unnecessary, and I don't think it will happen. As YesNo says, This is exactly what "artificial intelligent" robots are for, and we can see the results on Mars very well from that. They take samples, analyse them, and range pretty freely across the planet, filming as they go.

[YesNo]

There is an astronomical radio source at the center of our galaxy called Sagittarius A* which some believe to be a black hole. https://en.wikipedia.org/wiki/Sagittarius_A*#Discovery_of_G2_gas_cloud_on_an_acc retion_course

There was also supposed to be an event where a gas cloud, G2, was to collide with this alleged black hole last year. However, G2 survived the encounter with the black hole. Does that mean the radio source Sgr A* is not the location of a black hole?

[Dreamwoven]

Perhaps when we get more reliable information about the astronomical radio source at the centre of our galaxy called Sagittarius A* we may be in a position to draw conclusions?

[YesNo]

Yes, Sagittarius A* does represent something so far unknown. Only a few days ago, I thought black holes existed. Now, I am ready to doubt that they even can exist.

However, if I doubt that such singularities exist, then whatever the universe was at the Big Bang, it could not have been like a black hole. To remove the idea from my mind that there was a beginning some 14 billion years ago, one would have to find something in the universe older than 14 billion years.

[Dreamwoven]

Another dwarf planet has been found in the sun's orbit far out in the Kuiper Belt: http://www.space.com/31100-most-distant-dwarf-planet-found.html. Two or three time further out than Pluto (and smaller), it hasn't yet had its orbit plotted, as has been done for Eris (http://www.space.com/28379-eris-dwarf-planet.html).

[YesNo]

In checking that link about the new dwarf planet, there was one about Vesta, the brightest asteroid: http://www.space.com/12097-vesta-asteroid-facts-solar-system.html

There were two things I found interesting about it: (1) Supposedly Vesta can at times be seen without binoculars and (2) Gauss calculated its orbit in 10 hours without computers.

That second thing made me wonder how he did that? What were his input values and the formulas he used?

[Dreamwoven]

I think we still have not had the closet pass by Dawn to this asteroid. Or have we? This film sequence of a really close pass is quite stunning: http://www.space.com/17389-take-a-tour-of-vesta-the-giant-asteroid-explored-by-nasa-s-dawn-spacecraft-video.html.

Gauss' work has a good page on this: https://www.math.rutgers.edu/~cherlin/History/Papers1999/weiss.html

[Dreamwoven]

I must have missed this post (http://www.space.com/29503-nasa-insight-mars-lander-begins-testing.html) now 6 months old: NASA preparing for the next robotic Mars lander InSight (http://www.space.com/29503-nasa-insight-mars-lander-begins-testing.html), to examine the interior of the planet.

[YesNo]

The use of the cubesats in the coming mission sounds interesting: http://www.space.com/29489-marco-cubesats-mars-landing-2016.html

Thanks for the link describing how Gauss found the orbit of Vesta. He only had a set of observations which contained time and two degree measurements to pinpoint the asteroid.

[Dreamwoven]

I had missed that, YesNo: cubesats in the next Mars lander. i am really glad that NASA is spending so much effort in exploring the next nearest neighbour to Earth (Venus beats Mars but is far more difficult to explore).

This post was a good way of trying to imagine the vast distances of space: http://earthsky.org/astronomy-essentials/how-far-is-a-light-year?

[Dreamwoven]

Discovery of the furthest known galaxy: http://earthsky.org/space/scientists-measure-most-distant-galaxy-yet. 13.8 billion years old.

[YesNo]

I think that would be about 13 billion years old with the universe itself at 13.8 billion years. It is interesting that these objects are so faint that spectroscopy may not work. It looks like we need bigger telescopes.

[Dreamwoven]

This from EarthSky:
Many universes? Until recent decades, most astronomers would have told you that, by definition, the word universe means all there is. That word was used to describe all space, time, matter, physical laws and constants. But now a new word – multiverse – has entered the language of scientists.

Not all scientists agree, but some – including Stephen Hawking, for example, and Alan Guth of MIT – believe there’s scientific justification for a multiverse, many universes springing into being, possibly existing simultaneously, each possibly with its own physics. If true, then our universe of stars and galaxies is just a small part of this vast assemblage of many universes.

There is a growing interest in parallel universes, rather than just one universe, and not just one big bang, but several. This is discussed in http://earthsky.org/space/bumping-up-against-a-parallel-universe?

[YesNo]

In Charles Lawrence's talk on the Planck mission results he claimed there wasn't any evidence in the data for multiverses. He also didn't even know what to measure in the data that would show a multiverse. See the part toward the end about 1:30 and following for this discussion: https://www.youtube.com/watch?v=ZCZdrfDHwgU

That makes me think there isn't any "scientific justification" for a multiverse. However, if one needs certain metaphysical assumptions about the universe to be true then there might be philosophical justifications that could save those assumptions by invoking a random multiverse. All we would have to go on are whether the justifications are rational or not. There is no data, hence no scientific justification.

The main problem is that the cosmic microwave background is evidence that our universe had a beginning. It is not eternal. Did something conscious start the universe? If so, then one has theism. So the basic metaphysical assumption underlying these multiverse theories is the need to avoid theism. This is done by assuming there must be a random multiverse. This would restore the eternal and unconscious nature of the universe. However, it does not help explain the existence of our own consciousness.

My personal view is that there is a non-random, intentional multiverse. If the big bang happened once, it happened many times. There is a consciousness that started all of these universes and they are all able to support life.

[Dreamwoven]

Another question that arose is where in the universe did the big bang take place and so provide the centre of the universe out of which it expanded? Presumably the heart of the universe can be identified, by measuring the distance from this "centre". Where, for example is our own galaxy the Milky Way in this pattern of explosion?

[YesNo]

I am thinking there should be a center as well, but I understand that space and time started with the big bang. If that is the case, the big bang happened everywhere in our space and time. However, it is hard for me to think of space and time having a beginning.

One thing Lawrence mentioned in his talk was that someone looking at the cosmic microwave background from a different part of the universe would see something different.

I was thinking about the multiverse a bit more. It seems that life requires that the universe be finite based on Olber's paradox: https://en.wikipedia.org/wiki/Olbers%27_paradox If there were infinitely many stars, the night sky would be black and too hot for life to survive. So each universe is finite and this allows us to exist.

[tailor STATELY]

"Scientists capture a black hole swallowing a star for the first time ever" - http://releases.jhu.edu/2015/11/26/scientists-get-first-glimpse-of-black-hole-eating-star-ejecting-high-speed-flare-2/

Ta ! (short for tarradiddle),
tailor STATELY

[YesNo]

I searched for ASASSN-14li which I assume is the name associated with this along with "tidal disruption event". I wonder what Mersini-Houghton thinks of that event.

[Dreamwoven]

The multiverse theory: https://en.wikipedia.org/wiki/Laura_Mersini-Houghton. Sorry, not checked my mail for some days...

[YesNo]

She may be wrong about the cosmic microwave background showing evidence for a multiverse. I understand the Planck data does not show enough variability that something besides randomness cannot account for it. Also I don't understand why another universe would have a gravitational effect on our universe. They are in separate spaces. They shouldn't touch.

It seems she is also interested in many worlds. This is different from a multiverse. Each universe would have multiple versions of itself to account for quantum indeterminacy. I don't think that's a coherent interpretation of quantum physics.

So maybe she is wrong about the black holes as well. According to the link, "She claimed that Hawking radiation causes the star to shed mass at a rate such that it no longer has the density sufficient to create a black hole." In her favor there isn't much evidence to go on. The ASASSN-14li might be explainable in other ways than a black hole consuming a star. It is after all in another galaxy and the predicted collision in our galaxy's center did not happen.

[The Atheist]

An astronomy thread?

Why didn't someone tell me?

Serious amateur astronomer for about 40 years. I'll be checking back to see what's been going on.

[Dreamwoven]

Welcome to the astronomy thread!

[YesNo]

Yes, welcome back. There's also a cosmology thread you might be interested in.

I was hoping to see the moon and Venus this morning, but the sky was overcast.

[Dreamwoven]

The Atheist - you are probably far ahead of us - or at least of me. I was inspired to start this thread because of the recent discoveries in our own solar system, New Horizons, the explorations of Mars (which shows just how unnecessary it will be to send astronauts to Mars). And this is just the beginning. The future is clearly with unmanned exploration, I think.

It would be interested to learn more about what kind of amateur astronomy you have been involved in. I have no equipment to speak of, only a 7x50 binoculars - asaklitt, decent quality but better for birdwatching than stargazing...There is not even a local astro club near me...So I follow space.com and EarthSky.org (http://earthsky.org) on a regular basis, and am a member of the British popular astronomy society. Read the Swedish equivelent, too, at local libraries - populär astronomi (http://www.popularastronomi.se).

[Dreamwoven]

SPA: Electronic News Bulletin No. 411 2015 December 6 (Electronic News Bulletin No. 411 2015 December 6)

A team of astronomers using the Very Large Telescope (VLT) has captured detailed images of the hypergiant star VY Canis Majoris. The observations show how the unexpectedly large size of the particles of dust surrounding the star enable it to lose an enormous amount of mass as it begins to die. That process, understood now for the first time, is necessary to prepare such gigantic stars to meet their explosive demise as supernovae. VY CMa is a stellar goliath, a red hypergiant, one of the largest stars known in the Milky Way. It is 30 or 40 times the mass of the Sun and 300,000 times (nearly 14 magnitudes) more luminous. In its current state, the star would encompass the orbit of Jupiter, having expanded tremendously as it entered the final stages of its existence. The new observations of the star were made with the SPHERE instrument on the VLT. The adaptive-optics system of that instrument corrects images to a higher degree than earlier systems. It allows features very close to bright sources of light to be seen in great detail. SPHERE clearly revealed how the brilliant light of VY CMa was lighting up clouds of material surrounding it. The team could not only see into the heart of the cloud of gas and dust around the star, but could also see how the starlight was scattered and polarised by the surrounding material. Those measurements were key to discovering the properties of the dust, and revealed the grains of dust to be comparatively large particles, half a micron across, which may seem small, but it is about 50 times larger than the dust normally found in interstellar space.

[The Atheist]

Cheers!

A couple of bits that may already be under discussion:

The Japan probe to Venus is finally in orbit - 5 years late (http://www.theverge.com/2015/12/7/9865072/jaxa-venus-spacecraft-akatsuki-orbit-insertion).

and the LISA Pathfinder, about to prove gravitational theories (http://www.theguardian.com/commentisfree/2015/dec/07/einstein-universe-gravitational-waves-theory-relativity).

My telescope is one of these (http://www.skywatcher.com/product.php?cat=4&id=245).

Fully motorised, with many thousands of pre-programmed positions that work off a GPS. It means you don't have to waste too much time looking for what you want to see. Excellent for planets & nebulae.

The astronomy comes in handy at times, like when we saw a bolide a few months ago (http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11400450). In 40 years of watching the sky I've never seen anything remotely as impressive as that. The thing that struck me - and probably as a result of being in a very quiet place - was the sound! It was an amazing hissing that made us look at the sky, only to see it bursting through the atmosphere. No question it was an outer solar system rock; it was much, much faster than any meteor I've seen.

Out of this world, you might say!

[Dreamwoven]

A fellow-Londoner, and with a decent telescope! The link to The Guardian article was interesting. And the Japanese Venus probe. It seems that different countries are specialising in different planets to investigate further, like NASA on Mars. Good to specialise, especially when each planet poses its own problems. There is an article on this in Scace.com today: http://www.space.com/31300-japan-akatsuki-spacecraft-venus-orbit-try.html

Venus has been very prominent in the skies in recent months, bright and clear. Feel free to publish any pictures on this website.

[The Atheist]

A fellow-Londoner, and with a decent telescope!

Almost!

Well, almost exactly opposite London on the globe. I'm down t'other end. NZ.

[YesNo]

The gravitational wave observatory is interesting.

What do you view with your telescope, Atheist? I have only 7x50 binoculars which are most useful when I am in Wisconsin where the sky is dark.

[The Atheist]

Nebulae and planets, mostly. The prettiest bits, which is all any shop-bought amateur scope is good for. The moon is really cool through a good 'scope as well.

I'm inheriting $350,000,000 from Nigeria in a couple of weeks' time and I've decided I'm going to buy the Mt John observatory (http://www.tekapotourism.co.nz/info/mt_john.html)! One of the darkest places on the planet which is easily accessible.

[Dreamwoven]

That would be amazing, to own an entire space observatory. Look forward to learning more.

[Dreamwoven]

From SPA (Society for Popular Astronomy) Newsletter 40
New planet, or even planets?
Papers just published* suggest that there could be a hitherto undiscovered planet or even a brown dwarf star in the outer Solar System – or, more likely, it is just a smaller asteroid much closer. One object, dubbed Gna, has appeared on observations of the variable star W Aquilae made using ALMA, the Atacama Large Millimeter/submillimeter Array (above) on three occasions in March, April and May 2014. It had apparently moved between the first two observations, but was absent on the third. This could simply be because it is a fairly close object, a Centaur asteroid of maximum size 880 km, and had moved out of the field of view.
But the Swedish authors of the paper speculate that the movement is also consistent with a very remote planet or even a brown dwarf on the outskirts of the Solar System, though it would have to be highly variable to account for its disappearance in the third observation. However, in another paper, ALMA observers say that they have found a source close to the star Alpha Centauri, also moving over a ten-month period, which had not been previously detected. They rule out a new member of the Alpha Centauri system, but instead claim that it belongs to the Solar System, either a distant brown dwarf or a ‘super Earth’ in the Kuiper Belt.
The claims have been dismissed by other astronomers. Planetary scientist Mike Brown points out that ‘if it is true that ALMA accidentally discovered a massive outer solar system object in its tiny tiny tiny field of view that would suggest that there are something like 200,000 Earth sized planets in the outer solar system.’ This, he says, would destabilise the whole Solar System – which clearly isn’t the case.

* Technically minded readers can decide for themselves by reading the (as yet unrefereed) papers:
http://arxiv.org/pdf/1512.02650v1.pdf
http://arxiv.org/pdf/1512.02652v1.pdf

[YesNo]

Just the idea that there could be a dwarf brown star in our solar system is something I didn't even consider.

I heard, and mentioned earlier, that there could be 200 planets like Pluto that are still undiscovered. All of this lack of knowledge about objects so close to us make me wonder about the accuracy of data claimed to come from other galaxies. Although I understand that our current knowledge about the cosmic microwave background is better than our knowledge of the universe about us. That might be because there is not much left to know about it.

[Dreamwoven]

Yes, it underlines how limited our knowledge is of our own galaxy. Even more so of our own solar system.

[Dreamwoven]

In Swedish the Milky Way is called The Winter Road (Vintergatan), which is an interesting reflection of the different cultural viewpoints...

[Dreamwoven]

There is an interesting piece in EarthSky on Ceres (http://earthsky.org/space/ceres-blurs-line-between-comet-and-asteroid), including the comment by Y. Whateley. It seems the composition of the ice on Ceres suggest its origins lie in the Kuiper Belt.

[YesNo]

So those bright spots are believed to be magnesium salts rather than an alien structure. Maybe Velikovsky was partly right as Whateley hints. I wonder what a possible set of orbits could have been for Ceres that would take it from the Kuiper belt to the Asteroid Belt.

[Dreamwoven]

The Journal Popular Astronomy has auroras as one of its special topics. I looked it up on 20 December when there was a lot of aurora activity on our latitude of 61 north. That morning at 5 am there had been a false dawn on the horizon due north of our house, a strip of clear sky, so it could have been that we saw. Dawn here in midwinter is around 9 am. There was probably colourful aurora (https://en.wikipedia.org/wiki/Aurora) activity, which was seen over all of Britain, even in the far south. But aurora are transitory phenomena so demand patience to watch and identify them. I can't do that as it means staying up for long hours, sacrificing sleep. This NASA page (http://www.nasa.gov/mission_pages/sunearth/news/gallery/aurora-index.html#.VneXB7yATFI) is also about auroras.

[YesNo]

This link from your NASA link shows an aurora from space: http://www.nasa.gov/content/goddard/how-the-sun-causes-an-aurora

They called this "space weather" and a "geomagnetic storm". I wonder why there are always in northern latitudes? Perhaps they are in southern latitudes as well.

[Dreamwoven]

There are aurora at both poles - aurora australis is the other one.

[prendrelemick]

Happy astronomical new year!

[Dreamwoven]

Thank you prendelemick! Happy astronomical year to you too.

This morning at 8 am it was still dark but the sun was soon going to rise. Before it did I was looking eastward out of the window at the sky lightening and for the first time I noticed the noctiluscent clouds (https://en.wikipedia.org/wiki/Noctilucent_cloud), presaging the dawn. They were very beautiful, and I spent several minutes admiring them. Tonight had been the shortest day of the year, so it was especially welcome.

[YesNo]

Happy Winter Solstice. Here is some information about what people do around Stonehenge during this time that I found by accident: http://www.telegraph.co.uk/news/science/12061231/When-is-the-shortest-day-of-the-year-the-winter-solstice-2015.html

I didn't realize there were things like noctiluscent clouds. From the pictures I can see how they might confuse them with regular clouds early in the morning or late in the evening.

[Dreamwoven]

Yes, they are, of course, ordinary regular clouds, but very high in the sky (at 85 to 76 km high) and so very cold, forming ice crystals, which reflect direct sunlight. They were only discovered (or publicly noticed) in 1885.

At first I didn't "notice" these clouds as being noctilucent, they were just pretty. But when I thought about it further and looked up noctilucent clouds it confirmed to me that this is what they are. The sun shines on them from below the horizon so it takes a specific combination of circumstances to see them. And then to classify them as a distinct phenomena. Now I know, I will keep an eye out for them in future.

[Dreamwoven]

The Kuiper Belt (https://en.wikipedia.org/wiki/Kuiper_belt) is where many of the minor planets (like Ceres, Pluto, Makemake, and Haumea and some of the Moons like Neptune's Triton and Saturn's Phoebe) are thought to have originated. Ceres is the most recent planet thought to have originated here.

We clearly know relatively little about the Kuiper belt and KBOs (Kuiper Belt Objects). See this extract from the Wikipedia item (https://en.wikipedia.org/wiki/Kuiper_belt) on it:

The Kuiper belt /ˈkaɪpər/ or /'køypǝr/[1] (as in Dutch), sometimes called the Edgeworth–Kuiper belt, is a circumstellar disc in the Solar System beyond the planets, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun.[2] It is similar to the asteroid belt, but it is far larger—20 times as wide and 20 to 200 times as massive.[3][4] Like the asteroid belt, it consists mainly of small bodies, or remnants from the Solar System's formation. Although many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia and water. The Kuiper belt is home to three officially recognized dwarf planets: Pluto, Haumea, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, are also thought to have originated in the region.[5][6]

See the posts of 12 16 2015 on this, earlier in this thread.

The Wikipedia article on KBOs continues and shows by its language how little we know of the Kuiper Belt:

The Kuiper belt was named after Dutch-American astronomer Gerard Kuiper, though he did not actually predict its existence. In 1992, 1992 QB1 was discovered, the first Kuiper belt object (KBO) since Pluto.[7] Since its discovery, the number of known KBOs has increased to over a thousand, and more than 100,000 KBOs over 100 km (62 mi) in diameter are thought to exist.[8] The Kuiper belt was initially thought to be the main repository for periodic comets, those with orbits lasting less than 200 years. However, studies since the mid-1990s have shown that the belt is dynamically stable, and that comets' true place of origin is the scattered disc, a dynamically active zone created by the outward motion of Neptune 4.5 billion years ago;[9] scattered disc objects such as Eris have extremely eccentric orbits that take them as far as 100 AU from the Sun.[nb 1]

[Dreamwoven]

I might as well continue with the references to the last and most distant area of solar influence, the Oort Cloud (https://en.wikipedia.org/wiki/Oort_cloud). The language degenerates further as the Oort Cloud is described in hypothetical language, like "thought to be..." and "thought to comprise..." and "astronomers conjecture that...". The Oort Cloud is thought to define the outer limits of the gravitational dominance of the sun, and the origins of a whole class of comets (like Halley's) that pass close to Earth at intervals.

This is a quote from the item:

The Oort cloud is thought to comprise two regions: a disc-shaped inner Oort cloud (or Hills cloud) and a spherical outer Oort cloud. Objects in the Oort cloud are largely composed of ices, such as water, ammonia, and methane.

Astronomers conjecture that the matter composing the Oort cloud formed closer to the Sun and was scattered far into space by the gravitational effects of the giant planets early in the Solar System's evolution.[3] Although no confirmed direct observations of the Oort cloud have been made, it may be the source of all long-period and Halley-type comets entering the inner Solar System, and many of the centaurs and Jupiter-family comets as well.[6]

It is striking how little we know of this area of space within the sun's sphere of influence!

[YesNo]

We don't know as much as I thought we did either, but I am glad they hesitate to say something definitely. They could have said, "The Oort cloud comprises two regions." I would have been more gullible and believed them. I am probably still too gullible.

One thing I didn't realize until reading the various links in this thread is that objects can be pushed away from the Sun by the gravitational effects of larger planets. I previously imagined that everything was doing its best to avoid falling into the Sun or one of the planets.

[Dreamwoven]

The Oort Cloud has continued to fascinate me. It is so far way that even Voyager 1 (which is the furthest out of the Voyager probes) will not reach it for another 300 years:

Space probes have yet to reach the area of the Oort cloud. Voyager 1, the fastest[53] and farthest[54][55] of the interplanetary space probes currently exiting the Solar System, will reach the Oort cloud in about 300 years[4][56] and would take about 30,000 years to pass through it.[57][58] However, around 2025, Voyager 1's radioisotope thermoelectric generators will no longer supply enough power to operate any of its scientific instruments, preventing any meaningful exploration by Voyager 1. The other four probes currently escaping the Solar System either are already or are predicted to be non-functional when they reach the Oort cloud, however it may be possible to find an object from the cloud that has been knocked into the inner solar system.

One proposal for exploration is to use a craft powered by a solar sail that would take around 30 years to reach its destination.[59] In the 1980s there was a concept for probe to reach 1000 AU in 50 years called TAU, among its missions would be to look for the Oort cloud.[60]

Other probes are in preparation, notably the Whipple Mission (https://en.wikipedia.org/wiki/Whipple_(spacecraft)), and the Whipple Discovery Mission (http://whipple.cfa.harvard.edu).

[YesNo]

I didn't realize the Oort Cloud was that far away. The solar sail technology looks promising.

Looking at the morning sky, I see that Jupiter and Venus are getting further and further apart in the sky. Supposedly Saturn is above the horizon but I haven't seen it yet.

[Dreamwoven]

Mercury is also above the horizon at this time, after sunset. An opportunity to see it. Planet shine with a steady light, they don't twinkle like stars. See http://earthsky.org/tonight/mercury-visible-in-western-sky-after-sunset

[Dreamwoven]

The headline at the 7.30 pm SVT news last night was that we may get to see the Northern Lights all over Sweden. I doubt we will from our home at least, just a glimpse at 5 am on the northern horizon. See this Space.com item (http://www.space.com/31484-sun-blasts-flare-at-earth-new-year-s-eve-storm.html?cmpid=NL_SP_weekly_2015-12-30).

[YesNo]

Based on the link it is interesting that these sunspot cluster eruptions affect us in two ways. First there is the "flare", which I assume comes at the speed of light and causes an "ionization event" which may cause radio blackouts. The second is the "coronal mass ejection" which takes time to reach us and appears as the northern lights a few days later.

I have been able to see Saturn in the morning sky, but not yet Mercury in the evening sky because of clouds.

[Dreamwoven]

I am gradually learning about the aurora (borealis and australis). We never see the full glory of curtains of shimmering blue, shifting and changing, not at our latitudes. You have to be inside the polar circle when the conditions are right. At 61 degrees north we see the light in the northern sky but no more. the australis must be even harder to see, as there is no continental land even at 60 degrees south, apart from Antarctica. There is an old Aberdeen song about the northern lights (http://www.aboutaberdeen.com/northern-lights-of-old-aberdeen.php).

[YesNo]

Here's a YouTube link to that song: https://www.youtube.com/watch?v=-SNODgG0Fd4

While watching the Sun rise this morning it occurred to me that the planets and finally the Moon are the last that can be seen in the sky as it brightens. The stars have long disappeared. The planets reflect the Sun and are nearer to us than the stars and it seems to make sense that they should remain visible longer than the stars. When I turned my back to the Sun I could see the entire landscape slowing increase its ability to reflect the Sun. Sharp shadows began to appear. I know all that is obvious. I just didn't quite realize it before.

[Dreamwoven]

The u-tube link has shots in it that make it clear that the northern lights (as shifting blue curtains) can be seen from Aberdeen, at 58 degrees north. So they can be seen in Southern Norrland at 61 degrees north, you just have to catch it at the right time, presumably staying up all night in clear weather. That was very useful to know.

[Dreamwoven]

The SOCIETY for POPULAR ASTRONOMY

Electronic News Bulletin No. 413 2016 January 3


GIANT COMETS COULD ENDANGER EARTH

RAS

A team of astronomers reports that the discovery of hundreds of giant comets in the outer regions of the Solar System over the last two decades implies that those objects pose a much greater hazard to life than asteroids. The giant comets, termed centaurs, have unstable orbits crossing the paths of the massive outer planets Jupiter, Saturn, Uranus and Neptune. The planetary gravitational fields can occasionally deflect the objects towards the Earth. Centaurs are typically 50 to 100 kilometres across, or larger, and a single such body has more mass than the entire population of Earth-crossing asteroids found to date. Calculations of the rate at which centaurs enter the inner Solar System indicate that one will be deflected onto a path crossing the Earth's orbit about once every 40,000 to 100,000 years. Whilst in near-Earth space, they are expected to disintegrate into dust and larger fragments, flooding the inner Solar System with cometary debris and making impacts on our planet inevitable.

Known severe upsets of the terrestrial environment and interruptions in the progress of ancient civilizations, together with our growing knowledge of interplanetary matter in near-Earth space, indicate the arrival of a centaur around 30,000 years ago. That giant comet would have strewn the inner planetary system with debris ranging in size from dust all the way up to lumps several kilometres across. Specific episodes of environmental upheaval around 10,800 BCE and 2,300 BCE, identified by geologists and palaeontologists, are also consistent with the new understanding of cometary populations. Some of the greatest mass extinctions in the distant past, for example the death of the dinosaurs 65 million years ago, may similarly be explained on the giant-comet hypothesis. In the last three decades scientists have invested a lot of effort in tracking and analysing the risk of a collision between the Earth and an asteroid. But we need to look beyond our immediate neighbourhood too, and look out beyond the orbit of Jupiter to find centaurs. Those distant comets could be a serious hazard. The researchers have also uncovered evidence from disparate fields of science in support of their model. For example, the ages of the sub-millimetre craters identified in lunar rocks returned in the Apollo programme are almost all younger than 30,000 years, indicating a vast enhancement in the amount of dust in the inner Solar System since then.

[Dreamwoven]

This from earth/sky: http://earthsky.org/earth/four-new-elements-added-to-periodic-table

[YesNo]

I thought they found all the elements already. It looks like there is no end to the number of these provided we can build the technology necessary to fuse them. I like how the article called them "superheavies".

I've been watching the morning sky more recently along with the sunrise. Nothing unusual to report except that it is all amazing.

Beth Moon has a collection of photographs of stars and old trees: http://www.bethmoon.com/DiamondNights.html

In her artist's statement she mentioned two experimental results from the University of Edinburgh and Lawrence Edwards correlating changes in plants and changes in our solar system and galaxy.

[The Atheist]

Some astronomers in our South Island got a much longer session than they expected at Mt St John Observatory: http://www.stuff.co.nz/the-press/75752994/Stargazers-forced-to-spend-night-in-cafe-during-gale-force-winds

[Dreamwoven]

The AstroCafe with glass roofs is a great idea. Can see part of the Milky Way from it.

[YesNo]

An enclosure with glass roofs is all I really need.

[Dreamwoven]

And minimal light pollution, which the sit also has. Seems to have clear skies, too.

[swathisharan]

I am also new to this forum and hope it will be useful for me.

[Dreamwoven]

Welcome to the forum and the astronomy thread. Would you like to tell its a bit about yourself and your interest in astronomy?

[YesNo]

Welcome, swathisharan! One of the things I've found useful about this thread is I started looking at the planets and the Moon. I even know some constellations now.

[Dreamwoven]

How sofia flight revealed Pluto secrets. (http://www.space.com/31605-how-sofia-flight-revealed-pluto-secrets.html?cmpid=NL_SP_weekly_2016-1-15)

[Dreamwoven]

Nebulae and planets, mostly. The prettiest bits, which is all any shop-bought amateur scope is good for. The moon is really cool through a good 'scope as well.

I'm inheriting $350,000,000 from Nigeria in a couple of weeks' time and I've decided I'm going to buy the Mt John observatory (http://www.tekapotourism.co.nz/info/mt_john.html)! One of the darkest places on the planet which is easily accessible.

I've been checking some of the details on this Observatory. Here are some links:

Canterbury on NZ South Island (https://en.wikipedia.org/wiki/Canterbury,_New_Zealand) seems to be a good location for a major observatory. Mt. John Observatory has its own wikipedia page (https://en.wikipedia.org/wiki/Mount_John_University_Observatory), and here is more info on it (http://www.phys.canterbury.ac.nz/research/mt_john/index.shtml) (including a fine 360 degree view from it.).

[tailor STATELY]

Loopy String theory ? a possibility: https://www.quantamagazine.org/20160112-string-theory-meets-loop-quantum-gravity/ ... or not.


But a number of factors may be pushing the camps closer together. New theoretical findings have revealed potential similarities between LQG and string theory. A young generation of string theorists has begun to look outside string theory for methods and tools that might be useful in the quest to understand how to create a “theory of everything.” And a still-raw paradox involving black holes and information loss has given everyone a fresh dose of humility.


Herman Verlinde, a theoretical physicist at Princeton University who frequently works on string theory, finds it plausible that methods from LQG can help illuminate the gravity side of the duality. In a recent paper, Verlinde looked at AdS/CFT in a simplified model with only two dimensions of space and one of time, or “2+1” as physicists say. He found that the AdS space can be described by a network like those used in LQG. Even though the construction presently only works in 2+1, it offers a new way to think about gravity. Verlinde hopes to generalize the model to higher dimensions. “Loop quantum gravity has been seen too narrowly. My approach is to be inclusive. It’s much more intellectually forward-looking,” he said.

I tried to watch the video which I think depicts the "2+1" model ( flatland ! ) expanding to a higher order of dimensionality, but my bandwidth cap gaks it (I'll be able to watch during a 2am - 8am pst stint later Monday morning {good grief it's only 23 seconds long !!!})

I haven't the math nor knowledge to fully grasp either theory, but I still find it fascinating that we may be able to better understand black holes and gravity, and the universe in general, better some day.

Ta ! (short for tarradiddle),
tailor STATELY

[Dreamwoven]

This is very interesting, I have looked up Quanta Magazine (https://www.quantamagazine.org) and the Simons Foundation (https://www.simonsfoundation.org/#), and your post combines the interest in Astronomy and parts of another thread on this forum that I also subscribe to, on Cosmology (http://www.online-literature.com/forums/showthread.php?82648-Cosmology) whose two main contributors are desiresjab and YesNo.

I wasn't aware of Quanta Magazine, nor of the Simons Foundation before reading your post, but will keep myself better informed on this in future: thanks!

[Dreamwoven]

Today's Dagens Nyheter (http://www.dn.se/nyheter/vetenskap/roterande-svarta-hal-driver-universums-starkaste-ljuskallor/) has an article on black holes in association with the award of the Crafoord Prize (http://www.crafoordprize.se) for 2016 on Mathematics and Astronomy (this is in English). The prize is awarded to those who develop research that is not covered by the Nobel Prize).

[YesNo]

One of the things I found interesting in the reference Tailor STATELY cited was another article claiming that supersymmetry had been falsified: https://www.quantamagazine.org/20121120-as-supersymmetry-fails-tests-physicists-seek-new-ideas/ This makes me wonder if string theory itself makes any sense, but I don't know enough about it.

I don't know whether there are black holes or not or what metaphysical difference it would make but I am beginning to doubt they exist, not just because theoretically "information" can't be lost in the black hole, whatever that information happens to be, but because we did not see the black hole that supposedly exists at the center of our galaxy "eat" a cloud last year as predicted. If we can't get predictions right at such close range, how can we trust data coming from other galaxies that black holes exist?

The whole thing about information is puzzling. On the one hand it implies that reality may have no substance in the usual sense, which I think is the case. One the other it implies information is still a form of unconsciousness, a reality that can be swallowed up in a black hole, which is something I doubt.

I admit that I'm a philosophical idealist which implies that I don't believe in the existence of unconscious matter. The position is the opposite of a philosophical materialist. So I have a bias that could be falsified if some unconscious matter could be found, but is information or waves of potentiality forms of unconsciousness? These metaphors are moving in the right direction, as I understand the word "right", but they still seem faulty to me.

[Dreamwoven]

I have to admit I missed that article in Quanta Magazine. It does, as you say, raise issues concerning the whole matter.

[Dreamwoven]

Solid evidence for a 9th planet: http://earthsky.org/space/solid-evidence-for-a-9th-planet-say-caltech-astronomers

[YesNo]

10 times more massive than the Earth. It is amazing what we might have missed. I wonder if it's discovery would eliminate the need for dark matter in our solar system?

[Dreamwoven]

Today space.com has an item on the next space telescope, WFIRST (http://www.space.com/31686-wfirst-work-on-nasas-spy-telescope-begins.html), due operational 2014. It may be this will do what you are looking for?

[The Atheist]

10 times more massive than the Earth. It is amazing what we might have missed. I wonder if it's discovery would eliminate the need for dark matter in our solar system?

No, even a planet 10X larger than Earth would be a midget against Jupiter and its gravitational impact would be negligible, which is why it's been hiding for so long.

The planets we do know about are putting on a stunning display at the moment, with Saturn, Jupiter, Mars & Venus in line with the rising sun. We've been waiting for a clear morning and were up at 4 to have a look.

Saturn in particular was sensational, with the moons gleaming like they'd been polished.

Best of all was as we were showing the 6 year old the Southern Cross, a meteor flitted past.

[YesNo]

Yes, the mornings can be very nice. I was up early this morning but it was overcast.

[Dreamwoven]

Atheist, You have an interest in astronomy, I see. Can you actually see the moons of saturn? What kind of telescope do you have?

[Dreamwoven]

The SOCIETY for POPULAR ASTRONOMY

Electronic News Bulletin No. 414 2016 January 24

Here is the latest round-up of news from the Society for Popular Astronomy. The SPA is arguably Britain's liveliest astronomical society, with members all over the world. We accept subscription payments online at our secure site and can take credit and debit cards. You can join or renew via a secure server or just see how much we have to offer by visiting http://www.popastro.com/

EVIDENCE OF A REAL NINTH PLANET

California Institute of Technology

Caltech researchers have found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer Solar System. The object, which the researchers have nicknamed Planet Nine, is supposed to have a mass about 10 times that of the Earth and orbits about 20 times further from the Sun on average than Neptune (which does so at an average distance of 2800 million miles). In fact, it would take the (still-hypothetical) planet between 10,000 and 20,000 years to orbit round the Sun. The researchers' evidence for the planet's existence came through mathematical modelling and computer simulations; they have not observed the object directly. There have been only two true planets discovered since ancient times, and this would be a third. The putative ninth planet -- at 5,000 times the mass of Pluto -- is sufficiently large that there should be no debate about whether it is a true planet. Unlike the class of smaller objects now known as dwarf planets, Planet Nine gravitationally dominates its neighbourhood of the Solar System. In fact, it dominates a region larger than any of the known planets.

The road to the theoretical discovery was not straightforward. In 2014, astronomers noted that 13 of the most distant objects in the Kuiper Belt are similar with respect to an obscure orbital feature. To explain that similarity, they suggested the possible presence of a small planet. A year-and-a-half-long collaboration began to investigate the distant objects. Fairly quickly it was realized that the six most distant objects from the original 13 under study all follow elliptical orbits that point in the same direction in space. That is particularly surprising because the outermost points of their orbits move around the Solar System, and they travel at different rates. It is almost like having six hands on a clock all moving at different rates, and when you happen to look up, they're all in exactly the same place. The odds of having that happen are something like 1 in 100. But on top of that, the orbits of the six objects arealso all tilted in the same way -- pointing about 30 degrees downward in the same direction relative to the plane of the eight known planets. The probability of that happening is about 0.007%. It could not happen randomly, so something must be shaping the orbits.

The first possibility investigated by astronomers was that perhaps there are enough distant Kuiper-Belt objects -- some of which have not yet been discovered -- to exert the gravity needed to keep that sub-population clustered together. The researchers quickly ruled that out when it turned out that such a possibility would require the Kuiper Belt to have about 100 times the mass that it actually has. That left them with the idea of a planet. Their first instinct was to run simulations involving a planet in a distant orbit that encircled the orbits of the six Kuiper-Belt objects, acting like a giant lassoo to wrangle them into their alignment. That almost works but does not provide the observed eccentricities precisely. Then, effectively by accident, the team noticed that if they ran their simulations with a massive planet in an anti-aligned orbit -- an orbit in which the planet's closest approach to the Sun, or perihelion, is 180 degrees away from the perihelion of all the other objects and known planets -- the distant Kuiper-Belt objects in the simulation assumed the alignment that is actually observed. Through a mechanism known as mean-motion resonance, the anti-aligned orbit of the ninth planet actually prevents the Kuiper-Belt objects from colliding with it and keeps them aligned. As orbiting objects approach each other they exchange energy. So, for example, for every four orbits Planet Nine makes, a distant Kuiper-Belt object might complete nine orbits. They never collide. Instead, like a parent maintaining the arc of a child's swing by periodic pushes, Planet Nine nudges the orbits of distant Kuiper-Belt objects such that their configuration with relation to the planet is preserved.

Planet Nine's existence helps to explain more than just the alignment of the distant Kuiper-Belt objects. It also provides an explanation for the curious orbits that two of them trace. The first of those objects, dubbed Sedna, was discovered in 2003. Unlike standard-variety Kuiper-Belt objects, which can get gravitationally 'kicked out' by Neptune but can then return back to it, Sedna never gets very close to Neptune. A second object like Sedna, known as 2012 VP113, was announced in 2014. The presence of Planet Nine in its proposed orbit naturally produces Sedna-like objects by taking a standard Kuiper-Belt object and slowly pulling it away into an orbit less connected to Neptune. But the real clincher for the researchers was the fact that their simulations also predicted that there would be objects in the Kuiper Belt on orbits inclined perpendicularly to the plane of the planets. In the last three years, observers have identified four objects tracing orbits roughly along one perpendicular line from Neptune and one object along another. Where did Planet Nine come from and how did it end up in the outer Solar System? Scientists have long believed that the early Solar System began with four planetary cores that went on to grab all of the gas around them, forming the four gas planets -- Jupiter, Saturn, Uranus, and Neptune. Over time, collisions and ejections shaped them and moved them out to their present locations. But there is no reason why there could not have been five cores, rather than four. Planet Nine could represent that fifth core, and if it got too close to Jupiter or Saturn, it could have been ejected into its distant, eccentric orbit. Researchers continue to refine their simulations and learn more about the planet's orbit and its influence on the distant Solar System. Meanwhile, astronomers have begun searching the skies for it. Only a rough orbit is indicated, not the precise location of the planet. If the planet happens to be close to its perihelion, astronomers should be able to find it in images captured by previous surveys. If it is in the most distant part of its orbit, the world's largest telescopes will be needed to see it. If, however, Planet Nine is now located anywhere in between, many telescopes might have a shot at finding it.

[YesNo]

I wonder if it would become visible without a telescope at some point in the future?

I'm surprised that many smaller planets would not have the same gravitational effect as one large one.

[Dreamwoven]

We do know that Jupiter acts as a magnet for all sorts of stray asteroids, like the one that broke up into smaller bits and that crashed into Jupiter.

[Dreamwoven]

This is an interesting explanation of the birth of our moon.

http://www.space.com/31763-moon-creating-impact-mixed-lunar-earth-rocks.html?cmpid=NL_SP_weekly_2016-1-29

Very violent, and creating a moon that is unusually-large in terms of the relationship between the earth and the moon, such that tides play an important part in creating earth's seas, and producing a very lively interaction.

[Dreamwoven]

http://earthsky.org/space/is-our-milky-way-galaxy-a-zombie?

A "dead" galaxy, that has stopped producing more stars? An interesting thought...

[YesNo]

Using the zombie metaphor seems odd. The galaxy is just not as active in producing new stars as others are. But those newer, blue stars don't live as long as the red ones. So maybe being a zombie means a longer life.

It was interesting that they needed help from volunteers to manually classify galaxies at the galaxyzoo site.

[Dreamwoven]

galaxy zoo is a new idea to me, not come across it before. I've added it to my astronomy tags. The website talks about the zooniverse...

Thanks, YesNo.

[YesNo]

I haven't actually gone to the site since I figured I wouldn't have time to volunteer for any of the activities they might have at the moment, but it is interesting that there is something any of us could do to help these guys. We could become more than consumers of this information.

[Dreamwoven]

Pluto has strange floating hills. Read about them here (http://earthsky.org/space/pluto-has-mysterious-floating-hills?utm_source=EarthSky+News&utm_campaign=b63f51f9ba-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-b63f51f9ba-394044013)

[Dreamwoven]

Whenever US Global hegemony is challenged, as it is now by Russia (Putin), cut-backs in the space programme appear to be threatened. See http://www.space.com/31886-nasa-2017-budget-request-reactions.html?cmpid=NL_SP_weekly_2016-2-10

[Dreamwoven]

Gravitational waves (http://earthsky.org/space/have-scientists-discovered-gravitational-waves?utm_source=EarthSky+News&utm_campaign=0c3705dd6b-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-0c3705dd6b-394044013) look likely to be confirmed today.

Its not clear why this would be so revolutionary, Einstein predicted this way back, but EarthSky seem to think it would be.

[tailor STATELY]

Another source... 'chirp': http://www.nytimes.com/2016/02/12/science/ligo-gravitational-waves-black-holes-einstein.html?_r=0

A team of scientists announced on Thursday that they had heard and recorded the sound of two black holes colliding a billion light-years away, a fleeting chirp that fulfilled the last prediction of Einstein’s general theory of relativity.

That faint rising tone, physicists say, is the first direct evidence of gravitational waves, the ripples in the fabric of space-time that Einstein predicted a century ago (Listen to it here.) It completes his vision of a universe in which space and time are interwoven and dynamic, able to stretch, shrink and jiggle. And it is a ringing confirmation of the nature of black holes, the bottomless gravitational pits from which not even light can escape, which were the most foreboding (and unwelcome) part of his theory.

More generally, it means that a century of innovation, testing, questioning and plain hard work after Einstein imagined it on paper, scientists have finally tapped into the deepest register of physical reality, where the weirdest and wildest implications of Einstein’s universe become manifest"

Ta ! (short for tarradiddle),
tailor STATELY

[YesNo]

I'm glad they got LIGO to detect something of interest. Now to overcome my cognitive dissonance over the existence of black holes.

[Dreamwoven]

What cognitive dissonance is that, YesNo?

[YesNo]

Like all cognitive dissonance, it's confusing to explain.

A few weeks ago, I had no problem with black holes. I didn't think about them. Then I heard they could not exist. That was the first cognitive dissonance I had to confront on the subject. So I thought about it and checked out some internet sources and I figured it makes sense that they do not exist since we didn't see what we expected at the center of our galaxy. So I overcame that cognitive dissonance by changing my mind about black holes.

Now I hear that gravity waves are supposed to imply the existence of something like black holes causing those gravity waves. That is the second cognitive dissonance. It sort of puts me back into my original position, but that isn't very comforting. Now I will have to learn more about black holes. If they are neutron stars, it relieves the dissonance a bit, because they are larger than a point in space about the size of what started the big bang.

I don't have any problem with gravity waves as such because I never thought of them.

[Emil Miller]

Like all cognitive dissonance, it's confusing to explain.

A few weeks ago, I had no problem with black holes. I didn't think about them.

I didn't either. Clearly, great minds don't think alike.

[Dreamwoven]

There has still nothing been said about how this changes things. Just knowing about the existence of gravity waves isn't enough. Can we use the knowledge, perhaps by utilising their existence in some way or other. A bit like how sailing can utilise water waves? Which direction do the waves go? From the black hole outwards or into the black hole?

[YesNo]

I think of the black hole as a pebble dropped into the ocean, but that would mean it is pushing waves away from it. The black hole would likely be attracting those waves--at least metaphorically.

Also, how did they know where to point their instrument? And doesn't it seem a little too convenient that those black holes merged together just in time for this instrument to detect it? And how did they separate those specific black holes from all the others out there making gravity waves?

There is nothing like cognitive dissonance to generate skepticism.

[Dreamwoven]

I think of black holes as being either pushing waves away from it or drawing waves into it. But its all speculation at this point in time. A bit like the warp drive (https://en.wikipedia.org/wiki/Warp_drive) in Star Trek. Some galaxies, like the Milky Way, are quiescent and others are very active, producing many new stars.

[YesNo]

The warp drive is interesting. I suspect the speed of light even in a vacuum may have some variance, that is, it is not a mathematical constant. If that is the case light might be able to go faster or slower. North Star pointed out in another thread that Lene Hua found a way to make light stop: https://www.youtube.com/watch?v=-8Nj2uTZc10

If one thinks about light's speed then we are within space and time, otherwise we couldn't measure anything. However, the non-local behavior of entangled particles is not just "faster" than light. It is instantaneous. There is no space or time to restrict it. Or at least, so I suspect at the moment.

[Dreamwoven]

Its odd that we are only just learning more about other galaxies than our own. All the fancy telescopes like James Webb Space Telescope (http://jwst.nasa.gov). We now see how galaxies collide and produce new stars. It is a whole new world out there.

[Dreamwoven]

More news on Black Holes and Gravitation Waves (http://www.space.com/31945-gravitational-wave-detection-black-holes-science.html?cmpid=NL_SP_weekly_2016-2-17).

[YesNo]

That article makes me wonder what is a black hole. If it is a collapsed star so that the light can no longer escape, that seems possible. That is not a "singularity". It is just a kind of star.

It is interesting that the pairs were calculated as having 29 and 36 times the mass of our Sun. That doesn't seem very large. Also they don't know precisely where this occurred, just a certain region of space. I guess what we need is another LIGO to pin point better the location of these objects.

Another thing I wonder about is when we are given a number like 29 times the mass of the Sun what is the margin of error for that calculation? I assume the margin of error is 0.5 because we are given a number precise to the units position, but it could be anything.

[Dreamwoven]

Another theory is that instead of a massive planet 9, there is a second Kuiper Belt (http://earthsky.org/space/is-planet-9-a-second-kuiper-belt?utm_source=EarthSky+News&utm_campaign=280970e899-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-280970e899-394044013) of many smaller objects: a Kuiper Belt 2.

[YesNo]

It is good to have multiple theories. If there is only one, I tend to assume it has been validated before much evidence is available. At least they aren't saying it is dark matter that is modifying the orbits of the Kuiper Belt objects.

[Dreamwoven]

This dragon-like salamander (http://earthsky.org/earth/rare-salamander-lays-eggs-in-slovenia-cave?utm_source=EarthSky+News&utm_campaign=8bcb31f3a4-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-8bcb31f3a4-394044013) has a life of up to 100 years. Live in the caves of Postonja in Slovenia. Recently found the first egg of this species.

[Dreamwoven]

EarthSky (http://earthsky.org/space/moons-might-hold-key-to-finding-e-t-life?utm_source=EarthSky+News&utm_campaign=7701a268fd-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-7701a268fd-394044013) has a nice article on the potential of moons to influence habitability on the planets moons often circulate around.

[YesNo]

It's interesting that the Moon stabilizes the seasons by keeping the Earth't tilt stable. But no known exomoons to date.

[Dreamwoven]

Most exmoons, like in our sun (star), will be too far away for us to identify them. How far away is the nearest star? Do we know if any planets orbit it? And even harder, how many moons orbit its planets, how large they are? We still know next to nothing about our galaxy, let alone the stars in the Milky Way Galaxy.

[YesNo]

We didn't even know that Pluto had moons until recently.

One of the things that puzzles me the most about astronomy is I don't know the margin of error around what we think is correct.

[Dreamwoven]

This post on Phobos is interesting: http://www.space.com/32152-mars-mysterious-moon-phobos-maven-photo.html?cmpid=NL_SP_weekly_2016-3-07. Its the closest moon to any planet so far discovered. And it is gradually spiralling into Mars. Strains in Phobos structure are beginning to show, as well.

[YesNo]

It is interesting that the moons of Mars were unknown prior to 1877 and in the 1950's it was conjectured that Phobos may be artificial because of its low orbit. This conjecture was later rejected. This comes from a link in the link you cited: http://www.space.com/20346-phobos-moon.html

[Dreamwoven]

See this interesting post in NeuroLogica Blog: http://theness.com/neurologicablog/index.php/jonathan-swift-predicted-the-moons-of-mars/. Not a bad guess by Jonathan Swift.

[YesNo]

It looks like Swift was satirizing scientists. I suspect he got the idea of Mars having two moons from Kepler.

[Dreamwoven]

Must have done. en.wikipedia.org/wiki/Moons_of_Mars

[Dreamwoven]

Two comets making close flybys of Earth in late March:

http://earthsky.org/space/twin-comets-approach-closely-in-march

[YesNo]

I'll see if I can find that comet this evening.

[Dreamwoven]

More on Pluto. We are beginning to learn a lot about our own solar system. An exciting time in astronomy: http://www.space.com/32301-pluto-surprising-discoveries-new-horizons.html

[YesNo]

I didn't expect Pluto to be still active. It is a good reminder that models and reality are not likely the same thing. Look closer and the models start falling apart. Of course one of the reasons to emphasize the new, model-shaking information that New Horizons has provided is to get an extended mission which requires funding. Since New Horizons is already out there, we might as well look.

[Dreamwoven]

This view of Comet LINEAR shows it to be 100 times righter than expected. See http://www.space.com/32376-how-to-see-green-comet-linear-in-march.html?cmpid=NL_SP_weekly_2016-3-25. See the post on Space.com for more information.

[YesNo]

It has been overcast, but I am hoping to see this before it fades away. Also I was expecting to see this in the evening, but it looks like the morning is the best time.

Here's a new video on Ceres: https://www.youtube.com/watch?v=AtLdprhvtVE

[Dreamwoven]

This post on multiverses is interesting: http://www.space.com/32452-can-science-explain-the-multiverse.html. I like ideas that turn to dominant theories of the day on their heads.

[Dreamwoven]

EarthSky reports that Cassini which has been orbiting Saturn for over 10 years cannot detect any effects of the 9th planet that can't be explained by what they know already: http://earthsky.org/space/planet-9-not-affecting-cassini-at-saturn.

[YesNo]

EarthSky reports that Cassini which has been orbiting Saturn for over 10 years cannot detect any effects of the 9th planet that can't be explained by what they know already: http://earthsky.org/space/planet-9-not-affecting-cassini-at-saturn.

It is easy to believe everything we hear and that's why it is good to hear arguments against an hypothesis. We can't check all this ourselves.

[YesNo]

This post on multiverses is interesting: http://www.space.com/32452-can-science-explain-the-multiverse.html. I like ideas that turn to dominant theories of the day on their heads.

These are interesting. At the moment I think I agree with Bas van Fraassen's strict empiricism as a limit for science. When one gets to speculations, the philosophers should take over. This might help the rest of us when we assess what actually has data to back it up and what only has logic.

[Dreamwoven]

http://www.space.com/32523-keplers-new-mission-to-hunt-strange-orphan-worlds.html. Quite an interesting discussion of orphan worlds.

[YesNo]

I noticed that the K2 project searching for orphan planets is only going to last three months. I guess if they don't find something using the microlensing technique in that time, the technique may need to be refined before continuing. There may be some other reason the project is so short.

[Dreamwoven]

That is probably the case.

[Dreamwoven]

This is interesting, how a star can strip away a planet's atmosphere.
http://earthsky.org/space/stars-strip-away-atmospheres-of-super-earths

[YesNo]

These exoplanets are likely close to their stars.

[Dreamwoven]

Certainly they are, the comparison can still be made to Mercury or even Venus. They may well have had life-encouraging atmospheres in their early days.

[Dreamwoven]

This post suggests there have been problems with Kepler, which may account for the uncertain nature of the observations, as Kepler was not working for about a week: http://earthsky.org/space/kepler-is-ok-spacecraft-recovered-from-emergency

[YesNo]

The K2 mission using gravity sounds like an interesting way to detect these exoplanets. I guess the previous technique was to see if planets made a transit of their stars.

[Dreamwoven]

Thee is a lot happening right now. See this project to launch postage-stamp sized probes to our nearest galaxy, Alpha Centauri. Sure, its all just hype and publicity, only taking 10 years to make the journey. The comments are more informed and interesting than the article!

http://www.space.com/32546-interstellar-spaceflight-stephen-hawking-project-starshot.html

Or 3 days to Pluto: http://www.space.com/32558-starshot-interstellar-probes-alien-life-solar-system.html

[YesNo]

It looks like they are getting smaller. I think you posted a link about small probes earlier, but not as small as postage stamps. The ultimate in size would be to send just a laser beam out and see what bounces back. I suspect this is sort of done now with determining the distance from the earth to the moon by having a beam bounce off a retroreflector we placed there, either with humans or robots, during the moon missions.

[Dreamwoven]

Its going to take a while before this project is launched, and then another 10 years before it arrives, I doubt I will still be around in 2035. But its fascinating how fast changes work!

[YesNo]

I got up in the middle of the night and noticed the Moon, Jupiter, Mars and Saturn across the sky through my window. They were the brightest objects out there with all the urban lighting. It made me realize how obvious these would have appeared to our ancestors looking up at the sky.

[Dreamwoven]

I've not seen these, the nights are too cloudy, but I'm sure you are right.

[Dreamwoven]

Sweden has its own space program, and its own space magazine - Populär Astronomi, that is published Quarterly. The centre for the research is in Kiruna, in the far north, where there is a rocket launch site. The Milky Way is called the Winter Street (vintergatan), same idea different language. There is a study to investigate the oldest stars in the galaxy, all near its centre.