It is also a very slow form of acceleration. You can't just go from standing to max speed in moments. Well suited to space travel but not on roads.
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It is also a very slow form of acceleration. You can't just go from standing to max speed in moments. Well suited to space travel but not on roads.
This is a good idea!
https://www.universetoday.com/137618...lpha-centauri/
They are already talking about greenhouses. I wonder if future scientists will discover any kind of vegetation.Quote:
Originally Posted by Dreamwoven
Certainly. One significant difference for me has come from this thread. When I look at the seemingly empty sky I imagine it crowded with suns, moons, planets, stars and splintered celestial bodies.Quote:
Originally Posted by Dreamwoven
I often think about how many of the planets have bits of space machinery circulating them in orbit (Ceres) - or on the surface (moon, Mars). One day, perhaps, this will become a history of space exploration.
I think that in a certain way this thread is partly documenting this history.Quote:
Originally Posted by Dreamwoven
Wow. The Solar System is shrinking to a spacial district:Quote:
Originally Posted by Dreamwoven
"Astronomers from the Minor Planet Center sent out an announcement today, hoping for astronomers to do followup observations on the comet C/2017 U1 PANSTARRS. That’s because this strange comet seems to be on a trajectory that originated outside our Solar System. Not just from the Oort Cloud, but from another star."
https://www.universetoday.com/137621...et-discovered/
Ditto:Quote:
Originally Posted by Dreamwoven
Finding planets beyond our Solar System is already tough, laborious work. But when it comes to confirmed exoplanets, an even more challenging task is determining whether or not these worlds have their own satellites – aka. “exomoons”. Nevertheless, much like the study of exoplanets themselves, the study of exomoons presents some incredible opportunities to learn more about our Universe."
https://www.universetoday.com/137615...-sized-planet/
Yes, it seems to be so. I have never heard of the Minor Planet Center. Couple of post being advertised. I'm too old for that, happy enough to be retired and with a pension I can live on.
And now that:
https://www.theguardian.com/science/...ystem-a2017-u1
I thought this was interesting!
https://www.universetoday.com/137642...ide-milky-way/
Those patches of snow are probably the remnants of Ceres' ocean.
https://www.universetoday.com/137656...t-ceres-ocean/
Yes, where there is snow there is water. At least, that´s how it used to be.
This article is related, what regards the constitution of planets.
"Astronomers discover sunscreen snow falling on hot exoplanet
Date:
October 26, 2017
Source:
Penn State
Summary:
Astronomers have used the Hubble Space Telescope to find a blistering-hot giant planet outside our solar system where the atmosphere 'snows' titanium dioxide -- the active ingredient in sunscreen. These observations are the first detections of this 'snow-out' process, called a 'cold trap,' on an exoplanet. The research provides insight into the complexity of weather and atmospheric composition on exoplanets, and may someday be useful for gauging the habitability of Earth-size planets."
https://www.sciencedaily.com/release...1026135325.htm
Yes, its strange how we keep getting caught out by such phenomena like snow falling on a planet that is very close to its star...
There are quite advanced plans to build a space telescope whose main task would be to investigate the planets round the nearest star to us Alpha Centauri: https://www.universetoday.com/137618...lpha-centauri/
Again a very expensive project.
About the blue moon...
"What Is a Blue Moon?
A "Blue Moon" is a fairly infrequent phenomenon involving the appearance of an additional full moon within a given period. But which period — there are two definitions of the term, and one was borne out of a misunderstanding of the other.
The older meaning defines a Blue Moon as the third full moon in a season that has four full moons. Called a seasonal Blue Moon, this occurs about every 2.5 years, according to NASA. Why the third moon? There are roughly 29.5 days between full moons, making it unusual for two full moons to fit into a 30- or 31-day-long month. (This means that February will never have a blue moon.) Seasons normally have three full moons, and some of them, for traditional and religious reasons, must occur at specific times of the year. So, the "Moon Before Yule" is always the one before Christmas.
The other meaning is that a Blue Moon is the second full moon within a single calendar month. This definition — a monthly Blue Moon — has gained popularity in recent years because of a misinterpretation of an almanac's original definition... "
https://www.space.com/15455-blue-moon.html
This is a neat topic, thank you, Danik!
https://www.universetoday.com/137641...hrust-records/
This is a post that indicates savings in both power and thrust while doing so very effectively. Just a small advance, perhaps but never the less worth noting.
https://astronomynow.com/2017/10/26/...ling-galaxies/
This is unexpected but potentially exciting. Evidence of the new physics?
Just registering:
"If this “wobbling” is not an unknown astrophysical phenomenon and in fact the result of the behaviour of dark matter, then it is inconsistent with the standard model of dark matter and can only be explained if dark matter particles can interact with each other – a strong contradiction to the current understanding of dark matter. This may indicate that new fundamental physics is required to solve the mystery of dark matter."
https://astronomynow.com/2017/10/26/...ling-galaxies/
Well, off to Mars!Quote:
Originally Posted by Dreamwoven
"When it comes to the future of space exploration, a number of new technologies are being investigated. Foremost among these are new forms of propulsion that will be able to balance fuel-efficiency with power. Not only would engines that are capable of achieving a great deal of thrust using less fuel be cost-effective, they will be able to ferry astronauts to destinations like Mars and beyond in less time.
...
Hall-effect thrusters have garnered favor with mission planners in recent years because of their extreme efficiency. They function by turning small amounts of propellant (usually inert gases like xenon) into charged plasma with electrical fields, which is then accelerated very quickly using a magnetic field. Compared to chemical rockets, they can achieve top speeds using a tiny fraction of their fuel."
Yes, that is my view too. It can still revolutionise our thinking.
Quote:
Originally Posted by Danik 2016
'Monster' planet discovery challenges formation theory
Date:
October 31, 2017
Source:
Royal Astronomical Society
Summary:
A giant planet, which should not exist according to planet formation theory, has been discovered around a distant star.
"The existence of the 'monster' planet, 'NGTS-1b', challenges theories of planet formation which state that a planet of this size could not be formed around such a small star. According to these theories, small stars can readily form rocky planets but do not gather enough material together to form Jupiter-sized planets."
https://www.sciencedaily.com/release...1031105158.htm
Yes, this was interesting. The original post can be found here:
https://www.universetoday.com/137706...ary-formation/
"If this “wobbling” is not an unknown astrophysical phenomenon and in fact the result of the behaviour of dark matter, then it is inconsistent with the standard model of dark matter and can only be explained if dark matter particles can interact with each other – a strong contradiction to the current understanding of dark matter. This may indicate that new fundamental physics is required to solve the mystery of dark matter."
https://astronomynow.com/2017/10/26/...ling-galaxies/[/QUOTE]
https://www.universetoday.com/137706...ary-formation/
Some basic truths are starting to be questioned...
https://www.universetoday.com/137736...restrial-life/
"Despite the thousands of exoplanets that have been discovered by astronomers in recent years, determining whether or not any of them are habitable is a major challenge. Since we cannot study these planets directly, scientists are forced to look for indirect indications. These are known as biosignatures, which consist of the chemical byproducts we associate with organic life showing up in a planet’s atmosphere.
A new study by a team of NASA scientists proposes a new method to search for potential signs of life beyond our Solar System. The key, they recommend, is to takes advantage of frequent stellar storms from cool, young dwarf stars. These storms hurl huge clouds of stellar material and radiation into space, interacting with exoplanet atmospheres and producing biosignatures that could be detected."
The first sign of exoplanets?
Overlooked Treasure: The First Evidence of Exoplanets
Date:
November 1, 2017
Source:
NASA/Jet Propulsion Laboratory
Summary:
Mount Wilson is the site where some of the key discoveries about our galaxy and universe were made in the early 20th century. But there is a far lesser known, 100-year-old discovery from Mount Wilson -- one that was unidentified and unappreciated until recently: the first evidence of exoplanets.
"A detective story
It started with Ben Zuckerman, professor emeritus of astronomy at the University of California, Los Angeles. He was preparing a talk about the compositions of planets and smaller rocky bodies outside our solar system for a July 2014 symposium at the invitation of Jay Farihi, whom he had helped supervise when Farihi was a graduate student at UCLA. Farihi had suggested that Zuckerman talk about the pollution of white dwarfs, which are faint, dead stars composed of mainly hydrogen and helium. By "pollution," astronomers mean heavy elements invading the photospheres -- the outer atmospheres -- of these stars. The thing is, all those extra elements shouldn't be there -- the strong gravity of the white dwarf should pull the elements into the star's interior, and out of sight.
The first polluted white dwarf identified is called van Maanen's Star (or "van Maanen 2" in the scientific literature), after its discoverer Adriaan van Maanen. Van Maanen found this object in 1917 by spotting its subtle motion relative to other stars between 1914 and 1917. Astronomer Walter Sydney Adams, who would later become director of Mount Wilson, captured the spectrum -- a chemical fingerprint -- of van Maanen's Star on a small glass plate using Mount Wilson's 60-inch telescope. Adams interpreted the spectrum to be of an F-type star, presumably based on the presence and strength of calcium and other heavy-element absorption features, with a temperature somewhat higher than our Sun. In 1919, van Maanen called it a "very faint star."
Today, we know that van Maanen's Star, which is about 14 light-years away, is the closest white dwarf to Earth that is not part of a binary system.
"This star is an icon," Farihi said recently. "It is the first of its type. It's really the proto-prototype."
While preparing his talk, Zuckerman had what he later called a "true 'eureka' moment." Van Maanen's Star, unbeknownst to the astronomers who studied it in 1917 and those who thought about it for decades after, must be the first observational evidence that exoplanets exist."
https://www.sciencedaily.com/release...1101175446.htm
When it comes to how and where planetary systems form, astronomers thought they had a pretty good handle on things. The predominant theory, known as the Nebular Hypothesis, states that stars and planets form from massive clouds of dust and gas (i.e. nebulae). Once this cloud experiences gravitational collapse at the center, its remaining dust and gas forms a protoplanetary disk that eventually accretes to form planets.Quote:
Originally Posted by Dreamwoven
However, when studying the distant star NGTS-1 – an M-type (red dwarf) located about 600 light-years away – an international team led by astronomers from the University of Warwick discovered a massive “hot Jupiter” that appeared far too large to be orbiting such a small star. The discovery of this “monster planet” has naturally challenged some previously-held notions about planetary formation.
https://www.universetoday.com/137739...ife-enceladus/
Ever since the Cassini mission entered the Saturn system and began studying its moons, Enceladus has become a major source of interest. Once the probe detected plumes of water and organic molecules erupting from the moon’s southern polar region, scientists began to speculate that Enceladus may possess a warm-water ocean in its interior – much like Jupiter’s moon Europa and other bodies in our Solar System.
In the future, NASA hopes to send another mission to this system to further explore these plumes and the interior of Enceladus. This mission will likely include a new instrument that was recently announced by NASA, known as the Submillimeter Enceladus Life Fundamentals Instrument (SELFI). This instrument, which was proposed by a team from the NASA Goddard Space Flight Center, recently received support for further development.
https://astronomynow.com/2017/10/14/...ntists-report/
Titan, the largest of Saturn’s more than 60 moons, has surprisingly intense rainstorms, according to research by a team of UCLA planetary scientists and geologists. Although the storms are relatively rare — they occur less than once per Titan year, which is 29 and a half Earth years — they occur much more frequently than the scientists expected.
“I would have thought these would be once-a-millennium events, if even that,” said Jonathan Mitchell, UCLA associate professor of planetary science and a senior author of the research, which was published Oct. 9 in the journal Nature Geoscience. “So this is quite a surprise.”
Interesting links, DW. I`ll come back for a closer reading after breakfast.Quote:
Originally Posted by Dreamwoven
Anyway it looks as if the current stage of astronomy is one more of new discoveries than one of definite conclusions.
I agree there is very little about which we can draw definite conclusions. The last week has been particularly poor in that respect.
A very interesting feature of Astronomy is the comparative method, which in your last links refers to wheater. Who would have thought two decades ago that it would be able to compare the weather on distant moons?
Good point, Danik. We take such things for granted.
Another query. I don't understand the carnival of space item: https://www.universetoday.com/137741...l-space-532-2/
I suppose its this:
"If you run a space/astronomy related blog, and would like to get more awareness, participate in the Carnival of Space. Every week, a different webmaster or blogger hosts the carnival, showcasing articles written on the topic of space. It’s a great way to get to know the community, and to help your writing reach a wider audience. If you’d like to be a host for the carnival, please send email to [email protected]" Its followed by several topics.
https://www.universetoday.com/12019/carnival-of-space/
OK, thanks, that was similar to my impression.