The pale-orange coloration around the 39-mile (62-km) -wide Kuiper crater on Mercury is evident in this image, a color composition made from targeted images acquired by NASA’s MESSENGER spacecraft on September 2, 2011.
The color may be due to compositional differences in the material that was ejected during the impact that formed the crater.
Kuiper crater is named after Gerard Kuiper, a Dutch-American astronomer who was a member of the Mariner 10 team. He is regarded by many as the father of modern planetary science.
“Kuiper studied the planets… at a time when they were scarcely of interest to other astronomers. But with new telescopes and instrumentation, he showed that there were great things to discover, which is as true today as it was then.”
– Dr. Bill McKinnon, Professor of Planetary Sciences at Washington University in St. Louis
Airless worlds like Mercury are constantly bombarded with micrometeoroids and charged solar particles in an effect known as “space weathering”. Craters with bright rays — like Kuiper — are thought to be relatively young because they have had less exposure to space weathering than craters without such rays.
See the original image release on the MESSENGER site here.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Poster art for the Russian Phobos-Grunt mission. Russian Federal Space Agency)/IKI
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Russia says “eish odin ras”* for its Mars moon lander mission, according to Roscomos chief Vladimir Popovkin.
If the European Space Agency does not include Russia in its ExoMars program, a two-mission plan to explore Mars via orbiter and lander and then with twin rovers (slated to launch in 2016 and 2018, respectively), Roscosmos will try for a “take-two” on their failed Phobos-Grunt mission.
“We are holding consultations with the ESA about Russia’s participation in the ExoMars project… if no deal is reached, we will repeat the attempt,” said Popovkin on Tuesday.
Phobos-Grunt, an ambitious mission to land on the larger of Mars’ two moons, collect samples and return them to Earth, launched successfully on November 9, 2011. It became caught in low-Earth orbit shortly afterwards, its upper-stage engines having failed to ignite.
After many attempts to communicate with the stranded spacecraft, Phobos-Grunt re-entered the atmosphere and impacted on January 15. Best estimates place the impact site in the Pacific Ocean off the coast of southern Chile.
The failed mission also included a Chinese orbiter and a life experiment from The Planetary Society.
Russia is offering ESA the use of a Proton launch vehicle for inclusion into the ExoMars mission, now that the U.S. has canceled its joint participation and Atlas carrier. Roscomos and ESA are scheduled to discuss the potential partnership in February.
The orbit of asteroid 433 Eros brings it close to Earth on Jan. 31. (www.astronomerswithoutborders.org)
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As the bright Mars-crossing asteroid 433 Eros makes its closest approach to Earth since 1975, astronomers around the globe are taking the opportunity to measure its position in the sky, thereby fine-tuning our working knowledge of distances in the solar system. Using the optical principle of parallax, whereby different viewpoints of the same object show slightly shifted positions relative to background objects, skywatchers in different parts of the world can observe Eros over the next few nights and share their images online.
The endeavor is called the Eros Parallax Project, and you can participate too!
Discovered in 1898, Eros was the largest near-Earth asteroid yet identified. Its close and relatively bright oppositions were calculated by astronomers of the day and used, along with solar transits by Venus (one of which, if you haven’t heard, will also occur this year on June 5!) to calculate distances in the inner solar system.
Having both events take place within the same year offers today’s astronomers an unparalleled opportunity to obtain observational measurements.
Through the efforts of the Astronomers Without Borders organization, along with Steven van Roode and Michael Richmond from the Transit of Venus project, anyone with moderate astrophotography experience can participate in the observation of Eros and share their photos via free online software.
Using the data gathered by individual participants positioned around the world, each with their own specific viewpoints, astronomers will be able to precisely measure the distance to Eros.
The more accurately that distance is known, the more accurately the distance from Earth to the Sun can be calculated – via the orbital mechanics of Kepler’s third law.
The tumbling motion of elongated 33-km-long Eros creates a changing brightness. (via transitofvenus.nl)
The last time such a bright pass of Eros occurred was in January of 1931. Observations of the asteroid made at that time allowed astronomers to calculate a solar parallax of 8″ .790, the most accurate up to that time and the most accurate until 1968, when data acquired by radar measurements gave more detailed measurements.
In many ways the 2012 close approach by Eros – astronomically close, but still a very safe 16.6 million miles (26.7 million km) away – will allow for a re-eneactment of the 1931 event… with the exception that this time amateur skywatchers will also contribute data, instantly, from all over the world!
One has to wonder…when Eros comes this close again in 2056, what sort of technology will we use to watch it then…
If you like math, music and space (separately or in any combination) you’re gonna love this. Musician Daniel Starr-Tambor has created a song by assigning each planet a note and speeding up the orbital periods of the planets where 2 seconds represents one Earth year, with a note playing for each orbit. But this isn’t just any typical song; it ends up being a musical palindrome, which means it can be played the same both forwards and backwards … that is, if you lived long enough to play to the end of the song. At the accelerated speeds of the Solar System, Starr-Tambor estimates it would continue without repetition for over 532.25 septendecillion years (5.3225 X 10 56). And with more than 62 vigintillion (6.2 X 10 64) individual notes, this composition, called “Mandala,” is the longest musical palindrome in existence.
Back in the 17th century composers like J.S. Bach created musical palindromes (mostly to show off!) and Starr-Tambor pays homage to Bach by choosing the precise position of the Solar System at the moment of Bach’s birth, viewed from the perspective of the Sun as it faces the constellation Libra, “so that each note chronicles his birthday on every planet.”
This radar image of asteroid 2005 YU55 was obtained on Nov. 7, 2011. Credit: NASA/JPL/Caltech.
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Look up in a clear night sky. How many moons do you see? Chances are, you’re only going to count to one. Admittedly, if you count any higher and you’re not alone, you may get some funny looks cast in your direction. But even though you may not be able to actually see them, there may very well be more moons out there orbiting our planet.
For the time being, anyway.
Today, Earth has one major moon in orbit around it. (Technically the Earth-Moon system orbits around a common center of gravity, called the barycenter, but that’s splitting hairs for the purpose of this story.) At one time Earth may have had two large moons until the smaller eventually collided into the larger, creating the rugged lump we now call the farside highlands. But, that was 4 billion years ago and again not what’s being referred to here.
Right now, at his moment, Earth may very well have more than the one moon we see in the night sky. Surprise.
Of course, it would be a very small moon. Perhaps no more than a meter across. But a moon nonetheless. And there could even be others – many others – much smaller than that. Little bits of solar system leftovers, orbiting our planet even farther out than the Moon we all know and love, coming and going in short-lived flings with Earth without anyone even knowing.
This is what has been suggested by researcher Mikael Granvik of the University of Helsinki in Finland. He and his colleagues have created computer simulations of asteroids believed to be occupying the inner solar system, and what the chances are that any number of them could be captured into Earth orbit at any given time.
Orbit of 2006 RH120, a confirmed TCO identified in 2006.
The team’s results, posted Dec. 20 in the science journal Icarus, claim it’s very likely that small asteroids would be temporarily captured into orbit (becoming TCOs, or temporarily captured objects) on a regular basis, each spending about nine months in up to three revolutions around Earth before heading off again.
Some objects, though, might hang around even longer… in the team’s simulations one TCO remained in orbit for 900 years.
“There are lots of asteroids in the solar system, so chances for the Earth to capture one at any time is, in a sense, not surprising,” said co-author Jeremie Vauballion, an astronomer at the Paris Observatory.
In fact, the team suspects that there’s most likely a TCO out there right now, perhaps a meter or so wide, orbiting between 5 and 10 times the distance between Earth and the Moon. And there could be a thousand smaller ones as well, up to 10 centimeters wide.
So if these moons are indeed out there, why don’t we know about them?
Put simply, they are too small, too far, and too dark.
At that distance an object the size of a writing desk is virtually undetectable with the instruments we have now.. especially if we don’t even know exactly where to look. But in the future the Large Synoptic Survey Telescope (LSST) may, once completed, be able to spot these tiny satellites with its 3200-megapixel camera.
Once spotted, TCOs could become targets of exploration. After all, they are asteroids that have come to us, which would make investigation all the easier – not to mention cheaper – much more so than traveling to and back from the main asteroid belt.
“The price of the mission would actually be pretty small,” Granvik said. And that, of course, makes the chances of such a mission getting approved all the better.
Read more on David Shiga’s article on New Scientist here.
Click on the image to download the full map and explore it in more detail.
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Was the early solar system bombarded with lots of big impacts? This is a question that has puzzled scientists for over 35 years. And it’s not just an academic one. We know from rocks on Earth that life began to evolve very early on, at least 3.8 billion years ago. If the Earth was being pummeled by large impacts at this time, this would certainly have affected the evolution of life. So, did the solar system go through what is known as the Late Heavy Bombardment (LHB)? Exciting new research, using data from the Lunar Reconnaissance Orbiter Camera (LROC) may cast some doubt on the popular LHB theory.
It’s actually quite a heated debate, one that has polarized the science community for quite some time. In one camp are those that believe the solar system experienced a cataclysm of large impacts about 3.8 billion years ago. In the other camp are those that think such impacts were spread more evenly over the time of the early solar system from approximately 4.3 to 3.8 billion years ago.
The controversy revolves around two large impact basins, which are found fairly close to each other on the Moon. The Imbrium basin is one of the youngest basins on the near side of the Moon, while the Serenetatis basin is thought to be one of the oldest. Both are flooded with volcanic basalts and are big enough to be seen from Earth with the naked eye.
What if the Apollo 17 samples didn't come from the Serenitatis basin, where the astronauts collected them, but rather from the Imbrium basin, located some 600 km away? Studies from the new Lunar Reconnaissance Orbiter Camera suggest this may be the case. If true, this means Serenitatis is much older than the Imbrium basin and a solar system-wide impact catastrophe is not needed to explain the uncannily close ages of the Imbrium and Serenitatis basins.
Image credit: NASA
Click on the image to download the full map and explore it in more detail.
Scientists know the relative ages of such lunar basins because of a concept called superposition. Basically, superposition states that what is on top must be younger than what is beneath. Using such relationships, scientists can determine which basins are older and which are younger.
To get an absolute age, though, scientists need actual bits of rock, so they can use radiometric dating techniques. The lunar samples returned by the Apollo program provided exactly that. But, the Apollo samples suggest that the Imbrium and Serenitatis basins are barely 50 million years apart.
Relative age dating tells us there are over 30 other basins that formed within that time frame. This means that roughly one major impact occurred every 1.5 million years! Now, 1.5 million years may sound like a long time. But consider the last large impact that happened on Earth, the Chicxulub event 65 million years ago, which is thought to have exterminated the dinosaurs. Imagine another 40 dinosaur-killing impacts occurring since then. It would be surprising if any life survived such a barrage!
This is why a team of researchers, led by Dr. Paul Spudis of the Lunar and Planetary Institute, is looking very carefully at this question. Their research is using the principle of superposition to show that several of the areas visited by the Apollo program were blanketed by material from the Imbrium impact. This could mean that many of the collected Apollo materials may be sampling the same event.
Dr. Spudis’s research focuses on the Montes Taurus area, between the Serenitatis and Crisium basins, not far from the Apollo 17 landing site. This is a region dominated by sculpted hills that have been interpreted to be ejected material from the adjacent Serenitatis basin impact. But, Dr. Spudis and his team have found that, instead, this sculpted material comes from the Imbrium basin some 600 kilometers away.
Previous data of this area, from the Lunar Orbiter IV camera, hadn’t shown this because a fog on the camera lens made the details difficult to see (this fog problem was eventually resolved, and Lunar Orbiter IV provided a lot of useful data on other parts of the Moon).The new LROC data, however, shows that the sculpted terrain seen at Apollo 17 is very widespread, extending far beyond the Montes Taurus region. Furthermore, the grooves and lineated features of this terrain point to the Imbrium basin, not the Serenitatis basin, and line up with similar features in the Alpes and Fra Mauro Formations, which are known to be ejecta from the Imbrium impact. In the north of Serenitatis, these Imbrium formations even seem to transform into the Montes Taurus, confirming that the sculpted hills do, in fact, originate from the Imbrium impact.
Recent high quality data from the Lunar Reconnaissance Orbiter Camera shows that the sculpted terrain, which is present at the Apollo 17 landing site, is related to material that is known to be from the Imbruim impact. This means that Apollo 17 may have sampled Imbrium and not Serenitatis material. This could explain the unusually close ages of these two basins, suggested by the Apollo samples. If so, the Serenitatis impact may have occurred much earlier than previously thought, meaning that a barrage of frequent bombardments did not occur, and life on Earth could have evolved without being molested by too many impact events.
Image credit: NASA/GSFC/Arizona State University
Click on the image to explore the LROC data in greater detail.
If the sculpted hills are Imbruim ejecta, then it is possible that Apollo 17 sampled Imbrium and not Serenitatis materials. That casts suspicion on the very close radiometric ages of these two basins. Perhaps these ages are so close because we effectively measured the same material. In that case, the age of Serenitatis could be much older than the 3.87 billion years the Apollo 17 samples suggest. If true, this would mean that there was no Late Heavy Bombardment at the time life was forming on the early Earth, leaving life to evolve with relatively few impact-related interruptions.
MESSENGER captures image of curious "hollows" around a crater peak
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The latest featured image from NASA’s MESSENGER spacecraft, soon to complete its first year in orbit around Mercury, shows the central peak of the 78-mile (138-km) – wide crater Eminescu surrounded by more of those brightly-colored surface features dubbed “hollows”. Actually tinted a light blue color, hollows may be signs of an erosion process unique to Mercury because of its composition and close proximity to the Sun.
First noted in September of last year, hollows have now been identified in many areas across Mercury. They showed up in previous images as only bright spots, but once MESSENGER established orbit in March of 2011 and began high-resolution imaging of Mercury’s surface it became clear that these features were something totally new.
The lack of craters within hollows seems to indicate that they are relatively young features. In fact, they may be part of a process that continues even now.
“Analysis of the images and estimates of the rate at which the hollows may be growing led to the conclusion that they could be actively forming today,” said David Blewett of the Johns Hopkins University Applied Physics Laboratory (APL).
One hypothesis is that the hollows are formed by the sublimation of subsurface material exposed during the creation of craters, around which they are most commonly seen. Being so close to the Sun (29 million miles/46 million km at closest) and lacking a protective atmosphere like Earth’s, Mercury is constantly being scoured by the powerful solar wind. This relentless stream of charged particles may literally be “sandblasting” exposed volatile materials off the planet’s surface!
The image above shows an area approximately 41 miles (66 km) across. It has been rotated to enhance perspective; see the original image and caption here.
Image: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Artist's conception of New Horizons during its flyby of Pluto in 2015. Credit:Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI)
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First there was the recent story about evidence for a possible subsurface ocean on Pluto, of all places. Now there is a new report regarding evidence for complex molecules on its surface, from scientists at Southwest Research Institute and Nebraska Wesleyan University. Little enigmatic Pluto is starting to get even more interesting…
The findings come from the Hubble Space Telescope, using the new and highly sensitive Cosmic Origins Spectrograph which indicate that there is a strong ultraviolet-wavelength absorber on the surface. This absorbing material is thought to likely be complex hydrocarbons and/or nitriles. The results have been published in the Astronomical Journal.
Pluto’s surface is known to be coated with ices composed of methane, carbon monoxide and nitrogen (it is extremely cold there!). The putative molecules can be produced by sunlight or cosmic rays interacting with those ices.
“This is an exciting finding because complex Plutonian hydrocarbons and other molecules that could be responsible for the ultraviolet spectral features we found with Hubble may, among other things, be responsible for giving Pluto its ruddy color,” said project leader Dr. Alan Stern.
The team also found evidence for surface changes in the ultraviolet spectrum, comparing current observations to those from the 1990s. The cause may be an increase in the pressure of Pluto’s tenuous atmosphere or different terrain which is being viewed at different times.
In a unique first for Universe Today, Dr. Alan Stern was the first researcher to be asked questions from readers via the comments section of this recent interview article by Ray Sanders. His answers to the top five questions (as ranked by “likes” on the discussion posts) will be posted soon in a subsequent article. Stern is also the principal investigator for the New Horizons spacecraft currently en route to Pluto.
A copy of the paper by Stern et al. is available here.
With all of the new discoveries already being made about Pluto, it should be very interesting when New Horizons gets there in 2015, providing us with the first close-up look of this fascinating little world.
Jupiter, the largest and most massive planet in our solar system, may be its own worst enemy. It turns out that its central core may in fact be self-destructing, gradually liquifying and dissolving over time. This implies it was previously larger than it is now, and may dissolve altogether at some point in the future. Will Jupiter eventually destroy itself completely? No, probably not, but it may lose its heart…
The core is composed of iron, rock and ice and weighs about ten times as much as Earth. That’s still small though, compared to the overall mass of Jupiter itself, which weighs as much as 318 Earths! The core is buried deep within the thick atmosphere of hydrogen and helium. Conditions there are brutal, with a temperature of about 16,000 kelvin – hotter than the surface of the Sun – and a pressure about 40 million times greater than the atmospheric pressure on Earth. The core is surrounded by a fluid of metallic hydrogen which results from the intense pressure deep down in the atmosphere. The bulk of Jupiter though is the atmosphere itself, hence why Jupiter (and Saturn, Uranus and Neptune) are called gas giants.
One of the primary ingredients in the rock of the core is magnesium oxide (MgO). Planetary scientists wanted to see what would happen when it is subjected to the conditions found at the core; they found that it had a high solubility and started to dissolve. So if it is in a state of dissolution, then it was probably larger in the past than it is now and scientists would like to understand the process. According to David Stevenson of the California Institute of Technology, “If we can do that, then we can make a very useful statement about what Jupiter was like at genesis. Did it have a substantial core at that time? If so, was it 10 Earth masses, 15, 5?”
The findings also mean that some exoplanets which are even larger and more massive than Jupiter, and thus likely even hotter at their cores, may no longer have any cores left at all. They would be indeed be gas giants in the most literal sense.
The conditions inside Jupiter’s core can’t be duplicated in labs yet, but the spacecraft Juno should provide much more data when it arrives at and starts orbiting Jupiter in 2016.
All these worlds are yours except Europa Attempt no landing there Use them together use them in peace
Despite that famous cryptic warning in the film 2010: The Year We Make Contact, NASA is planning for a possible attempted landing on Jupiter’s moon Europa. This is a mission that many people have been hoping for, since Europa is believed to have a liquid water ocean beneath the icy surface (as well as lakes within the surface crust itself), making it a prime location in the search for life elsewhere in the solar system. Two landers are being proposed which would launch in 2020 and land about six years later.
As stated by Kevin Hand of JPL, “Europa, I think, is the premier place to go for extant life. Europa really does give us this opportunity to look for living life in the ocean that is there today, and has been there for much of the history of the solar system.”
While the landers wouldn’t be able to access the ocean water which is well below the surface, they could analyze the surface composition with a mass spectrometer, seismometers and cameras. The mass spectrometer could detect organics on the surface if there are any. The landers probably wouldn’t last too long though, because of the intense radiation from Jupiter on the unprotected surface (as Europa has only a very slight, tenuous atmosphere). Accessing any of the water from its ocean or lakes would require drilling deep down, something for a more advanced future mission.
Another mission being considered is a Europa orbiter, which could also launch in 2020. In some ways that might be even better, as it could provide a broader detailed study of the moon over a longer time period. Of course if both missions could be done, that would be fantastic, but budgets will probably only allow for one of them. The lander mission is estimated to probably cost about $800 million to $2 billion, while an orbiter would cost about $4.7 billion.
It might be noted that a return mission to Saturn’s moon Enceladus would also be possible, especially since the water from its subsurface ocean or sea (depending on the various working models of its interior and geology) can be sampled directly from its water vapour geysers, no need to drill down. The Cassini spacecraft has already done that more than once, and has found organics of various complexities, but Cassini’s instruments can’t detect life itself.
Either destination would be exciting, as both are thought to be two of the most likely places in the solar system, besides Earth of course, to be inhabitable or even possibly inhabited. Everywhere on Earth where there is water, there is life. That may or may not be true for Europa or Enceladus, but we’ll never know unless we look.
