We have only seen the next imagers as blurs, but you can tell there are several objects including probably one moon. Out there in the Kuiper Belt gravity is much weaker.
We have only seen the next imagers as blurs, but you can tell there are several objects including probably one moon. Out there in the Kuiper Belt gravity is much weaker.
http://earthsky.org/space/interstell...e-violent-past
"The strange interstellar visitor to our solar system – dubbed ‘Oumuamua´ by astronomers – is tumbling as it moves through space. A new study suggests its chaotic tumble is likely to continue at least another billion years, and it suggests ‘Oumuamua’s tumble is the result of a violent collision with another asteroid in the past. This collision might have knocked ‘Oumuamua out of its original solar system and sent it toward our solar system.
Astronomer Wes Fraser of Queen’s University in Kingston, Ontario, Canada, led this new research. Fraser and his team analyzed all the available data from optical photometry; that is, they looked at the data on how ‘Oumuamua’s brightness varied over time. Then they used computer modeling to understand why ‘Oumuamua varied in brightness, and to spin out reasonable possibilities for its past and future. Their study was published in the peer-reviewed journal Nature Astronomy on February 9, 2018."
Stunning pictures of Jupiter (Juno Mission)
https://www.vox.com/science-and-heal...ew-photos-juno
"I seemed to have sensed also from an early age that some of my experiences as a reader would change me more as a person than would many an event in the world where I sat and read. "
Gerald Murnane, Tamarisk Row
Yes, very nice!
A new monthly number of astronomy posts:
The SOCIETY for POPULAR ASTRONOMY
Electronic News Bulletin No. 463 2018 February 18
Here is the latest round-up of news from the Society for Popular
Astronomy.
DOUBT CAST ON EVOLUTION OF MARTIAN LIFE
The University of Hong Kong
"Mars has long been of interest as a place to search for evidence of life
beyond the Earth, because the surface has numerous features that appear to be dried-up river channels and dried lake beds that hint at a warmer,
wetter, more-Earthlike climate in the past. However, new research has cast
doubt on the idea of surface life evolving on Mars. For the last 2.5
billion years, surface life on Earth has thrived largely through the
evolution of photosynthesis. Surface life is abundant and very successful
because of the availability of sunlight, surface water, generally moderate
climate conditions, and the protection of our magnetic field. But Mars would never
have experienced such habitable conditions at the surface.
Now scientists show that the climate of Mars has probably been extremely cold and dry most of the time. They argue that the familiar aqueous features on Mars include widespread, weathered soil horizons that could have formed in 'geologically' short climate 'excursions'. In other words, Mars has been cold and dry almost throughout its history and has only had abundant liquid water on its surface during relatively short episodes of climate change. However, all hope for life on Mars is not lost. The scientists point out that the prospects for surface life on Mars might be dim, but the possibilities for sub-surface life are promising. Life on Earth probably began in hydrothermal systems (environments where hot water reacts with rocks), and there is abundant evidence for many locations where hydrothermal environments existed on Mars at the time when life might have originated in similar environments on Earth. The scientists argue that, in order to understand how life formed on Earth, we should ignore the surface environments on Mars and focus exploration on hydrothermal deposits. Using infrared data on Mars collected by spacecraft, astronomers can interpret which minerals are there and describe the 'geology' of ancient hydrothermal systems. That type of work is based on laboratory measurements, which provide the necessary mineralogical background with which to interpret spectroscopic data from Mars."
The SOCIETY for POPULAR ASTRONOMY
Electronic News Bulletin No. 463 2018 February 18
Here is the latest round-up of news from the Society for Popular
Astronomy.
COMPOSITION OF TRAPPIST-1 PLANETS
ESO
The seven Earth-size planets of TRAPPIST-1 are all mostly made of rock, with some having the potential to hold more water than the Earth. The planets' densities, now known much more precisely than before, suggest that some of them could have up to 5 per cent of their mass in water -- which is 250 times more than the oceans on Earth. The form that water would take on TRAPPIST-1 planets would depend on the amount of heat they receive from their star, which is a mere 9 per cent as massive as our Sun. Planets closest to the star are more likely to have water in the form of atmospheric vapour, while those farther away may have water frozen on their surfaces as ice. TRAPPIST-1e is the rockiest planet of them all, but still is believed potentially to have some liquid water. Astronomers now know more about TRAPPIST-1 than about any other planetary system apart from our own. Since the extent of the TRAPPIST system was recognized in 2017 February, researchers have been working hard to characterize the planets better and to collect more information about them. The new study offers better estimates than were available previously for the planets' densities. The TRAPPIST name comes from the Transiting Planets and Planetesimals Small Telescope in Chile, which discovered two of the seven planets we know of today --announced in 2016. The Spitzer space telescope, in collaboration with ground-based telescopes, confirmed those planets and discovered the other five in the system. Since then, the Kepler space telescope has also observed the TRAPPIST-1 system, and Spitzer began a new programme of 500 additional hours of TRAPPIST-1 observations, which will conclude in March. The new body of data has helped the authors of the study to paint a clearer picture of the system than ever before -- although there is still much more to learn about TRAPPIST-1.
The TRAPPIST-1 planets huddle so close to one another that a person standing on the surface of one of them would have a spectacular view of the neighbouring planets in the sky. Those planets would sometimes appear larger than the Moon looks to an observer on Earth. They may also be tidally locked, meaning that the same side of the planet is always facing the star, with each side in perpetual day or night. Although the planets are all
closer to their star than Mercury is to the Sun, TRAPPIST-1 is such a cool
star that some of its planets could still, in theory, hold liquid water.
It is impossible to know exactly how each planet looks, because they are so
far away. In our own Solar System, the Moon and Mars have nearly the same density, yet their surfaces appear entirely different. TRAPPIST-1b, the innermost planet, is likely to have a rocky core, surrounded by an atmosphere much thicker than the Earth's. TRAPPIST-1c also probably has a rocky interior, but with a thinner atmosphere than planet b. TRAPPIST-1d is the lightest of the planets -- about three-tenths the mass of the Earth.
Scientists are uncertain whether it has a large atmosphere, an ocean or an
ice layer -- all three of those would give the planet an 'envelope' of
volatile substances, which would make sense for a planet of its density.
Scientists were surprised that TRAPPIST-1e is the only planet in the system
slightly denser than the Earth, suggesting that it may have a relatively
larger iron core than our home planet. Like TRAPPIST-1c, it does not
necessarily have a thick atmosphere, ocean or ice layer -- making those two
planets distinct in the system. It is a mystery why TRAPPIST-1e has a much
rockier composition than the rest of the planets. In terms of size, density
and the amount of radiation it receives from its star, it is the planet that
is most similar to the Earth. TRAPPIST-1f, g and h are far enough from the
host star that water could be frozen as ice on their surfaces. If they have
thin atmospheres, they would be unlikely to contain heavy molecules such as carbon dioxide.
Scientists can calculate the densities of the planets because their orbits
happen to be oriented in such a way that they transit in front of their
star, causing a slight dimming of the starlight. The amount of dimming is
related to the radius of the planet. To get the density, scientists take
advantage of what are called 'transit timing variations'. If there were no
other gravitational forces on a transiting planet, it would always cross in
front of its host star in the same amount of time -- for example, the Earth
orbits the Sun every 365 days. But because the TRAPPIST-1 planets are
packed so close together, they change the timing of one another's 'years'
ever so slightly. Those variations in orbital timing are used to estimate
the planets' masses. Then, mass and radius are used to calculate density.
The next step in exploring TRAPPIST-1 will be with the James Webb space
telescope, which may be able to determine whether these planets have
atmospheres and, if so, what those atmospheres are like. A recent study
using the Hubble telescope found no detection of hydrogen-dominated
atmospheres on planets TRAPPIST-1d, e and f -- another piece of evidence for rocky composition -- although a hydrogen-dominated atmosphere cannot be ruled out for good.
Sounds like a valid approach.The scientists argue that, in order to understand how life formed on Earth, we should ignore the surface environments on Mars and focus exploration on hydrothermal deposits. Using infrared data on Mars collected by spacecraft, astronomers can interpret which minerals are there and describe the 'geology' of ancient hydrothermal systems. That type of work is based on laboratory measurements, which provide the necessary mineralogical background with which to interpret spectroscopic data from Mars.
"I seemed to have sensed also from an early age that some of my experiences as a reader would change me more as a person than would many an event in the world where I sat and read. "
Gerald Murnane, Tamarisk Row
"I seemed to have sensed also from an early age that some of my experiences as a reader would change me more as a person than would many an event in the world where I sat and read. "
Gerald Murnane, Tamarisk Row
I thought this article very interesting too:
How does space change the human body?
NASA’s Twins Study sent one identical twin to space for a year, while the other stayed on Earth. Ten separate research projects then tracked how each twin changed.
http://www.astronomy.com/news/2018/0...the-human-body
I only didn´t understand why they sent the twin to space, that wasn´t an astronaut.
"I seemed to have sensed also from an early age that some of my experiences as a reader would change me more as a person than would many an event in the world where I sat and read. "
Gerald Murnane, Tamarisk Row
It is interesting how they research the differences. They have tried to do really far-reaching studies that explore the differences in great detail.
The SOCIETY for POPULAR ASTRONOMY
Electronic News Bulletin No. 463 2018 February 18
MASSIVE, DENSE SUPER-EARTH DETECTED
Carnegie Institution for Science
A star about 100 light-years away in the constellation Pisces, GJ 9827, has
what may be one of the most massive and dense super-Earth planets detected to date, according to new research. That new information provides evidence to help astronomers understand the process by which such planets form. The GJ 9827 star actually hosts three planets, discovered by the exoplanet-hunting Kepler/K2 mission, and all three are slightly larger than the Earth. That is the size that the Kepler mission found to be most common in the Galaxy with periods between a few and several hundred days. Intriguingly, no planets of that size exist in the Solar System. That makes scientists curious about the conditions under which they form and evolve. One important key to understanding a planet's history is its composition. Are these super-Earths rocky like our own planet? Or do they have solid cores surrounded by large, gassy atmospheres? To try to understand what an exo-planet is made of, scientists need to measure both its mass and its radius, which allow them to determine its bulk density. When quantifying planets in that way, astronomers have noticed a trend. It turns out that planets with radii greater than about 1.7 times that of the Earth have a gassy envelopes, like Neptune's, and those with radii smaller than that are rocky, like ours. Some researchers have proposed that the difference is caused by photo-evaporation, which strips planets of their envelopes of so-called volatiles -- substances like water and carbon dioxide that have low boiling points -- creating smaller-radius planets. But more information is needed to test that theory. That is why GJ 9827's three planets are special -- with radii of 1.64 (planet b), 1.29 (planet c) and 2.08 (planet d), they span the dividing line between super-Earth (rocky) and sub-Neptune (somewhat gassy) planets.
Luckily, scientists have been monitoring GJ 9827 with their Planet-Finding
Spectrograph (PFS), so they were able to constrain the masses of the three
planets with data in hand, rather than having to scramble to get many new
observations of GJ 9827. Usually, if a transiting planet is detected, it
takes months if not a year or more to gather enough observations to measure its mass. Because GJ 9827 is a fairly bright (tenth-magnitude) star, the team already had it in the catalogue of stars that it been monitoring for planets since 2010. The spectrograph was mounted on the Magellan Clay Telescopes at Las Campanas Observatory. The PFS observations indicate that planet b is roughly eight times the mass of the Earth, which would make it one of the most-massive and dense super-Earths yet discovered. The masses for planets c and d are estimated to be about two and a half and four times that of the Earth respectively, although the uncertainty in those two determinations is very high. That information suggests that planet d has a significant volatile envelope, and leaves open the question of whether planet c has a volatile envelope or not. But the better constraint on the mass of planet b suggests that that it is roughly 50% iron. More observations are needed to pin down the compositions of the three planets, but they do seem to be some of the best candidates to test our ideas about how super-Earths form and evolve.
The SOCIETY for POPULAR ASTRONOMY
Electronic News Bulletin No. 463 2018 February 18
PLANETS FOUND IN ANOTHER GALAXY
University of Oklahoma
A team of astronomers has discovered for the first time a population of
planets beyond the Milky Way galaxy. Using microlensing, researchers were able to detect objects in extragalactic systems that range from the mass of the Moon to the mass of Jupiter. The discovery was made using data from the Chandra X-ray Observatory, a telescope in space that is controlled by the Smithsonian Astrophysical Observatory. The small planets are the best candidates for observations by the microlensing technique. While planets are often discovered within the Milky Way using microlensing, the gravitational effect of even small objects can create high magnification, leading to a signature that can be modelled and explained in external galaxies. Until this study, there had been no evidence of planets in other galaxies. The galaxy concerned is 3800 million light-years away, and there is not the slightest chance of observing the planets directly. However, microlensing makes it possible to study them, unveil their presence and even obtain an idea of their masses.
Well, here we are with four new planets. It´s still early to say if the news are good or bad.
"I seemed to have sensed also from an early age that some of my experiences as a reader would change me more as a person than would many an event in the world where I sat and read. "
Gerald Murnane, Tamarisk Row
That was a poor post I made! Struggling to find something new on the astronomy front.
Idon´t think so. But there really isn´t much to report today.
With the approach of Valentine day, NASA seems to be getting sentimental. But the image is beautiful indeed.
A lonely beauty
Date:
February 14, 2018
Source:
ESA/Hubble Information Centre
Summary:
Beauty, grace, mystery -- this magnificent spiral galaxy has all the qualities of a perfect galactic Valentine. The galaxy NGC 3344 presents itself face-on, allowing astronomers a detailed look at its intricate and elegant structure. And Hubble's ability to observe objects over a wide range of different wavelengths reveals features that would otherwise remain invisible.
https://www.sciencedaily.com/release...0214150237.htm
"I seemed to have sensed also from an early age that some of my experiences as a reader would change me more as a person than would many an event in the world where I sat and read. "
Gerald Murnane, Tamarisk Row