Tag: dawn (page 2 of 6)

Dawn Enters Orbit Around Dwarf Planet Ceres ~ Video

March 9, 2015 / / 0 Comments

Ceres Dawn




Dwarf Planet Ceres

Excerpt from spacenews.com

NASA’s Dawn spacecraft arrived in orbit around the dwarf planet Ceres March 6, completing a journey of nearly seven and a half years and five billion kilometers.  In a statement, NASA’s Jet Propulsion Laboratory said Dawn entered orbit about 61,000 kilometers above Ceres at 7:39 am EST March 6, sending a signal to Earth about an hour later confirming it was in orbit and in good health.  “We feel exhilarated,” Dawn principal investigator Chris Russell said in the statement. “We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives.”

Dawn will gradually spiral down to its initial science orbit, 13,500 kilometers above Ceres, by April. Later in its mission Dawn will move gradually closer to the surface, eventually moving into an orbit of 375 kilometers.  The Dawn spacecraft, built by Orbital ATK, launched on a United Launch Alliance Delta 2 rocket in September 2007. After making a gravity assist flyby of Mars in February 2009, it entered orbit around the large main-belt asteroid Vesta in July 2011. It remained there for more than a year, using its ion thrusters to leave orbit in September 2012 to head to Ceres. 

Ceres, the largest object in the main asteroid belt between the orbits of Mars and Jupiter, was the first asteroid discovered by astronomers, in 1801. The International Astronomical Union designated Ceres a “dwarf planet” in 2006, a new category of objects that also includes the former planet Pluto.


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Dawn will gradually spiral down to its initial science orbit, 13,500 kilometers above Ceres, by April. Later in its mission Dawn will move gradually closer to the surface, eventually moving into an orbit of 375 kilometers.
The Dawn spacecraft, built by Orbital ATK, launched on a United Launch Alliance Delta 2 rocket in September 2007. After making a gravity assist flyby of Mars in February 2009, it entered orbit around the large main-belt asteroid Vesta in July 2011. It remained there for more than a year, using its ion thrusters to leave orbit in September 2012 to head to Ceres.
Ceres, the largest object in the main asteroid belt between the orbits of Mars and Jupiter, was the first asteroid discovered by astronomers, in 1801. The International Astronomical Union designated Ceres a “dwarf planet” in 2006, a new category of objects that also includes the former planet Pluto.
- See more at: http://spacenews.com/dawn-enters-orbit-around-ceres/#sthash.yoclEQI4.dpuf
WASINGTON — NASA’s Dawn spacecraft arrived in orbit around the dwarf planet Ceres March 6, completing a journey of nearly seven and a half years and five billion kilometers.
In a statement, NASA’s Jet Propulsion Laboratory said Dawn entered orbit about 61,000 kilometers above Ceres at 7:39 am EST March 6, sending a signal to Earth about an hour later confirming it was in orbit and in good health.
“We feel exhilarated,” Dawn principal investigator Chris Russell said in the statement. “We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives.”
- See more at: http://spacenews.com/dawn-enters-orbit-around-ceres/#sthash.yoclEQI4.dpuf

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8 possible explanations for those bright spots on dwarf planet Ceres

March 8, 2015 / / 0 Comments

Ceres  Excerpt from cnet.com It's a real-life mystery cliffhanger. We've come up with a list of possible reasons a large crater on the biggest object in the asteroid belt looks lit up like a Christmas tree.  We could be approachin...

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Fresh fossil studies push the dawn of man back to 2.8 million years

March 4, 2015 / / 0 Comments

(Reuters) - A 2.8-million-year-old jawbone fossil with five intact teeth unearthed in an Ethiopian desert is pushing back the dawn of humankind by about half a million years.Scientists said on Wednesday the fossil represents the oldest known repres...

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Astronomers Discover Ancient Dust Filled Galaxy ~ Debunks earlier theories that earliest galaxies had no dust only gas

March 3, 2015 / / 0 Comments


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Excerpt from voicechronicle.com


Astronomers have discovered a dust-filled ancient galaxy from the very early universe, which debunks earlier theories that earliest galaxies had no dust but gas. Astronomers from the University of Copenhagen used the Very Large Telescope’s X-shooter instrument along with the Atacama Large Millimeter/submillimeter Array and discovered a galaxy, named Galaxy A1689-zD1, which is an ancient galaxy and far from Earth.
The astronomers stated that the galaxy which
they were surprised to discover is far more evolved system than expected. It had a fraction of dust similar to a very mature galaxy, such as the Milky Way. Such dust is vital to life, because it helps form planets, complex molecules and normal stars. 

According to the astronomers A1689-zD1 is only observable by virtue of its brightness being amplified more than nine times by a gravitational lens in the form of the spectacular galaxy cluster. Without the gravitational boost, the glow from this very faint galaxy would have been too weak to detect.

The astronomers stated that they are viewing A1689-zD1 when the Universe was only about 700 million years old, which is 5% of its present age. According to them, it is a relatively modest system — much less massive and luminous than many other objects that have been studied before at this stage in the early universe and hence a more typical example of a galaxy at that time.

A1689-zD1 is being observed as it was during the period of reionization, when the earliest stars brought with them a cosmic dawn, illuminating for the first time an immense and transparent universe and ending the extended stagnation of the Dark Ages. Expected to look like a newly formed system, the galaxy surprised the observers with its rich chemical complexity and abundance of interstellar dust.

Dust plays an extremely important role in the universe – both in the formation of planets and new stars.

Darach Watson, Associate Professor at Dark Cosmology Centre, University of Copenhagen, and the lead author of the study, said, “After confirming the galaxy’s distance using the VLT we realized it had previously been observed with ALMA. We didn’t expect to find much, but I can tell you we were all quite excited when we realized that not only had ALMA observed it, but that there was a clear detection. One of the main goals of the ALMA Observatory was to find galaxies in the early Universe from their cold gas and dust emissions — and here we had it!”

The researchers hope that future observations of a large number of distant galaxies could help unravel how frequently such evolved galaxies occur in this very early epoch of the history of the universe.

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Skywatch: Venus and Jupiter continue to accentuate the night heavens

February 28, 2015 / / 0 Comments


Venus (right) & Jupiter


Excerpt from washingtonpost.com
By Blaine Friedlander Jr. 
In winter’s waning weeks, Venus and Jupiter continue to accentuate the night heavens, we change our clocks forward and we grab spring with no intention of letting go.

Check the west-southwestern heavens at dusk to spy the vivacious Venus and the dim Mars. In late February, the two planets met for a sweet cosmic waltz, but in March, they appear to separate. Venus approaches negative fourth magnitude (very bright) while Mars makes do at magnitude 1.3 (dim, hard to find in urban light pollution). With a clear sky, Mars looks like a red pinpoint. 

A young, waxing crescent moon visits Mars on the evening of March 21, and on the next evening the crescent flirts with Venus.
Robust Jupiter ascends the evening’s eastern sky. Find this gas giant at a -2.5 magnitude, very bright, in the constellation Cancer. The lion in the constellation Leo appears to stare at the planet. By the Ides of March, find it south around 10:30 p.m. 

The waxing gibbous moon drops by the dazzling Jupiter on March 2, days before the moon itself becomes full on March 5. 

Catch the ringed Saturn rising after midnight in the east-southeast now, hanging out near a gang of constellations, Scorpius, Ophiuchus and Libra. It’s a zero magnitude object, bright enough that it can be seen under urban skies. The waning moon loiters near Saturn before dawn on March 12. On that morning, the reddish star below them is Antares.
We adjust our clocks to Daylight Saving Time at 2 a.m. March 8. Spring forward, moving the clock ahead one hour. 

Winter is almost over. Spring is weeks away. The vernal equinox brings spring’s official arrival on March 20 at 6:45 p.m. 

Also on March 20 — the day a new moon — the North Atlantic and the Arctic waters get a short total eclipse. We won’t see it here, but Slooh.com will carry it live. Totality will start seconds after 5:44 a.m. and end at 5:47 a.m., according to Geoff Chester of the U.S. Naval Observatory. 

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As Dawn Spacecraft Approaches, A Second Mysterious Light Emerges on Planet Ceres

February 27, 2015 / / 0 Comments

Photo : NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI Excerpt from sciencetimes.com Originally discovered in 1801 by an astronomer in Sicily, Ceres has had quite an interesting history to date. Originally believed to be a shining star in the sky, when i...

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Monster Black Hole Is the Largest and Brightest Ever Found

February 25, 2015 / / 0 Comments



Largest and Brightest Black Hole
An artist's illustration of a monster supermassive black hole at the heart of a quasar in the distant universe. Scientists say the newfound black hole SDSS J010013.02+280225.8 is the largest and brightest ever found.

Excerpt from space.com

 Astronomers have discovered the largest and most luminous black hole ever seen — an ancient monster with a mass about 12 billion times that of the sun — that dates back to when the universe was less than 1 billion years old.

It remains a mystery how black holes could have grown so huge in such a relatively brief time after the dawn of the universe, researchers say.

Supermassive black holes are thought to lurk in the hearts of most, if not all, large galaxies. The largest black holes found so far in the nearby universe have masses more than 10 billion times that of the sun. In comparison, the black hole at the center of the Milky Way is thought to have a mass only 4 million to 5 million times that of the sun. 


Although not even light can escape the powerful gravitational pulls of black holes — hence, their name — black holes are often bright. That's because they're surrounded by features known as accretion disks, which are made up of gas and dust that heat up and give off light as it swirl into the black holes. Astronomers suspect that quasars, the brightest objects in the universe, contain supermassive black holes that release extraordinarily large amounts of light as they rip apart stars.
So far, astronomers have discovered 40 quasars — each with a black hole about 1 billion times the mass of the sun — dating back to when the universe was less than 1 billion years old. Now, scientists report the discovery of a supermassive black hole 12 billion times the mass of the sun about 12.8 billion light-years from Earth that dates back to when the universe was only about 875 million years old.

This black hole — technically known as SDSS J010013.02+280225.8, or J0100+2802 for short — is not only the most massive quasar ever seen in the early universe but also the most luminous. It is about 429 trillion times brighter than the sun and seven times brighter than the most distant quasar known.

The light from very distant quasars can take billions of years to reach Earth. As such, astronomers can see quasars as they were when the universe was young.

This black hole dates back to a little more than 6 percent of the universe's current age of 13.8 billion years.

"This is quite surprising because it presents serious challenges to theories of black hole growth in the early universe," said lead study author Xue-Bing Wu, an astrophysicist at Peking University in Beijing.

Accretion discs limit the speed of modern black holes' growth. First, as gas and dust in the disks get close to black holes, traffic jams slow down any other material that's falling into them. Second, as matter collides in these traffic jams, it heats up, emitting radiation that drives gas and dust away from the black holes.

Newfound Quasar SDSS J0100+2802
The newfound quasar SDSS J0100+2802 has the most massive black hole and the highest luminosity among all known distant quasars, as shown in this comparison chart of the black hole's mass and brightness.


Scientists still do not have a satisfactory theory to explain how these supermassive objects formed in the early universe, Wu said.

"It requires either very special ways to quickly grow the black hole or a huge seed black hole," Wu told Space.com. For instance, a recent study suggested that because the early universe was much smaller than it is today, gas was often denser, obscuring a substantial amount of the radiation given off by accretion disks and thus helping matter fall into black holes.

The researchers noted that the light from this black hole could help provide clues about the dark corners of the distant cosmos. As the quasar's light shines toward Earth, it passes through intergalactic gas that colors the light. By deducing how this intergalactic gas influenced the spectrum of light from the quasar, scientists can deduce which elements make up this gas. This knowledge, in turn, can provide insight into the star-formation processes that were at work shortly after the Big Bang that produced these elements.

"This quasar is the most luminous one in the early universe, which, like a lighthouse, will provide us chances to use it as a unique tool to study the cosmic structure of the dark, distant universe," Wu said.
The scientists detailed their findings in the Feb. 26 issue of the journal Nature.

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Dawn’s imagery of Ceres keeps getting better

February 18, 2015 / / 0 Comments


These two views of Ceres were acquired by NASA's Dawn spacecraft on Feb. 12, 2015, from a distance of about 52,000 miles (83,000 kilometers) as the dwarf planet rotated. The images, which were taken about 10 hours apart, have been magnified from their original size. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
These two views of Ceres were acquired by NASA’s Dawn spacecraft on Feb. 12, 2015, from a distance of about 52,000 miles (83,000 kilometers) as the dwarf planet rotated. The images, which were taken about 10 hours apart, have been magnified from their original size. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA



Excerpt from spaceflightnow.com

Images from NASA’s Dawn spacecraft on approach to the dwarf planet Ceres show a world pockmarked by craters and mysterious bright spots, and scientists are eager for a better look in the weeks ahead.

The latest images were taken Feb. 12 at a distance of 52,000 miles, or 83,000 kilometers, from Ceres. NASA released the fresh views Tuesday.

Every picture taken of Ceres in the coming weeks will show greater detail, as Dawn is set to be captured by the Texas-sized world’s gravity March 6. The dwarf planet will pull Dawn into the first of a series of survey orbits 8,400 miles from Ceres around April 23.

The imagery so far reveals Ceres as a cratered world, and Dawn will make a global map of the dwarf planet during its time in orbit.
But several bright spots have captured the attention of scientists.
“As we slowly approach the stage, our eyes transfixed on Ceres and her planetary dance, we find she has beguiled us but left us none the wiser,” said Chris Russell, principal investigator of the Dawn mission, based at UCLA. “We expected to be surprised; we did not expect to be this puzzled.”

The suspense is compounded by Dawn’s slow rate of approach. The probe’s ion propulsion system is gradually nudging Dawn on a trajectory closer to Ceres, eventually moving the spacecraft close enough to be grasped by the 590-mile diameter dwarf planet’s gravity.

“I want to know what is causing the bright spots,” Russell wrote in an email to Spaceflight Now. “The increased resolution seems to have moved us no closer to answering this mystery. I am frustrated by the suspense. This is the one problem of ion propulsion: We are closing in on Ceres very slowly.”

The latest photos have a resolution have 4.9 miles, or 7.8 kilometers, per pixel, according to a NASA press release.

Dawn’s framing camera will take its next set of images Feb. 20 at a range of about 30,000 miles. After late February, the resolution of Dawn’s imagery will be reduced as the spacecraft passes Ceres and flies in front of it, before being pulled closer in early April for insertion into orbit.

Soon after arriving in April, the spacecraft’s instruments will look for the signature of water vapor plumes shooting into space from the surface of Ceres, which may be blanketed in a crust of ice.
Dawn will orbit closest to Ceres in December at an altitude of 232 miles.

Dawn’s mission planners say the spacecraft could operate around Ceres until late 2016.

Ceres is the second destination for NASA’s Dawn mission, which launched in September 2007 and visited asteroid Vesta in 2011 and 2012.

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NASA probe snaps amazing image of Ceres

February 6, 2015 / / 0 Comments



    NASA's Dawn space probe has taken the sharpest-yet image of Ceres, a dwarf planet in our solar system's asteroid belt.

    Excerpt from SPACE.com

    By Mike Wall  

    NASA's Dawn spacecraft has taken the sharpest-ever photos of Ceres, just a month before slipping into orbit around the mysterious dwarf planet.

    Dawn captured the new Ceres images Wednesday (Feb. 4), when the probe was 90,000 miles (145,000 kilometers) from the dwarf planet, the largest object in the main asteroid belt between Mars and Jupiter.

    On the night of March 5, Dawn will become the first spacecraft ever to orbit Ceres — and the first to circle two different solar system bodies beyond Earth. (Dawn orbited the protoplanet Vesta, the asteroid belt's second-largest denizen, from July 2011 through September 2012.) 

    "It's very exciting," Dawn mission director and chief engineer Marc Rayman, who's based at NASA's Jet Propulsion Laboratory in Pasadena, California, said of Dawn's impending arrival at Ceres. "This is a truly unique world, something that we've never seen before."


    The 590-mile-wide (950 km) Ceres was discovered by Italian astronomer Giuseppe Piazzi in 1801. It's the only dwarf planet in the asteroid belt, and contains about 30 percent of the belt's total mass. (For what it's worth, Vesta harbors about 8 percent of the asteroid belt's mass.)

    Despite Ceres' proximity (relative to other dwarf planets such as Pluto and Eris, anyway), scientists don't know much about the rocky world. But they think it contains a great deal of water, mostly in the form of ice. Indeed, Ceres may be about 30 percent water by mass, Rayman said.

    Ceres could even harbor lakes or oceans of liquid water beneath its frigid surface. Furthermore, in early 2014, researchers analyzing data gathered by Europe's Herschel Space Observatory announced that they had spotted a tiny plume of water vapor emanating from Ceres. The detection raised the possibility that internal heat drives cryovolcanism on the dwarf planet, as it does on Saturn's moon's Enceladus. (It's also possible that the "geyser" was caused by a meteorite impact, which exposed subsurface ice that quickly sublimated into space, researchers said).

    The interior of Ceres may thus possess liquid water and an energy source — two key criteria required for life as we know it to exist.
    Dawn is not equipped to search for signs of life. But the probe — which is carrying a camera, a visible and infrared mapping spectrometer and a gamma ray and neutron spectrometer — will give scientists great up-close looks at Ceres' surface, which in turn could shed light on what's happening down below. 

    For example, Dawn may see chemical signs of interactions between subsurface water, if it exists, and the surface, Rayman said.
    "That's the sort of the thing we would be looking for — surface structures or features that show up in the camera's eye, or something about the composition that's detectable by one of our multiple spectrometers that could show evidence," he told Space.com. "But if the water doesn't make it to the surface, and isn't in large enough reservoirs to show up in the gravity data, then maybe we won't find it."

    Dawn will also attempt to spot Ceres' water-vapor plume, if it still exists, by watching for sunlight scattered off water molecules above the dwarf planet. But that's going to be a very tough observation to make, Rayman said.

    "The density of the water [observed by Herschel] is less than the density of air even above the International Space Station," he said. "For a spacecraft designed to map solid surfaces of airless bodies, that is an extremely difficult measurement." 

    Merging onto the freeway

    Dawn is powered by low-thrust, highly efficient ion engines, so its arrival at Ceres will not be a nail-biting affair featuring a make-or-break engine burn, as most other probes' orbital insertions are.

    Indeed, as of Friday (Feb. 6), Dawn is closing in on Ceres at just 215 mph (346 km/h), Rayman said —and that speed will keep decreasing every day.

    "You take a gentle, curving route, and then you slowly and safely merge onto the freeway, traveling at the same speed as your destination," Rayman said. "Ion propulsion follows that longer, more gentle, more graceful route."

    Dawn won't start studying Ceres as soon as it arrives. The spacecraft will gradually work its way down to its first science orbit, getting there on April 23. Dawn will then begin its intensive observations of Ceres, from a vantage point just 8,400 miles (13,500 km) above the dwarf planet's surface.

    The science work will continue — from a series of increasingly closer-in orbits, including a low-altitude mapping orbit just 230 miles (375 km) from Ceres' surface — through June 30, 2016, when the $466 million Dawn mission is scheduled to end.
    Rayman can't wait to see what Dawn discovers.

    "After looking through telescopes at Ceres for more than 200 years, I just think it's really going to be exciting to see what this exotic, alien world looks like," he said. "We're finally going to learn about this place."

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    Jupiter Wins the Starring Role in February’s Planet Parade

    February 6, 2015 / / 0 Comments

    Excerpt from nbc.com Planets are on parade in February's night sky. Giant Jupiter will dazzle all nig...

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    Dawn Probe’s Views of Ceres Add to Mystery of the Glowing White Spots

    February 5, 2015 / / 0 Comments



    Image: Ceres
    NASA / JPL-Caltech / UCLA / MPS / DLR / IDA
    A picture of Ceres from the Dawn spacecraft shows craters with central peaks on the surface. The pictures will become clearer as Dawn comes closer over the next month.

    Excerpt from nbcnews.com

    NASA's Dawn spacecraft is snapping increasingly detailed pictures of the dwarf planet Ceres as it zooms in for next month's rendezvous, but so far the images have only heightened the mystery surrounding bright spots on the surface. 
    The pictures released Thursday show that Ceres — the largest asteroid as well as the closest and smallest known dwarf planet — is pockmarked by craters. The craters are to be expected: The 590-mile-wide (950-kilometer-wide) mini-world has been pummeled for billions of years by other objects in the asteroid belt. But the white spots? They're a real puzzle. 
    One spot in particular has shown up prominently in pictures from the Hubble Space Telescope and from Dawn, which was launched back in 2007 to study Ceres and its sister asteroid Vesta. The latest pictures, taken on Wednesday from a distance of about 90,000 miles (145,000 kilometers), appear to show still more bright blips on Ceres. Are they patches of light material or ice at the bottom of craters? Or frost on the top of prominences?
    "We are at a phase in the mission where the curtain is slowly being pulled back on the nature of the surface," UCLA planetary scientist Chris Russell, the principal investigator for the $466 million mission, told NBC News in an email. "But the surface is different from that of other planets, and at this stage the increasing resolution presents more mysteries rather than answers them." 
    Russell said the science team was particularly interested in the big bright spot and the region surrounding it. 
    "Naively we expect a bright region to be fresh and a dark region to be old. So the surface of Ceres seems to have a number of circular features of varying freshness on a predominantly dark, presumably old surface," Russell wrote. "The one type of feature that clearly came into view this time were examples of central peak craters with overall similarity to large lunar craters." 
    The mysteries will be cleared up by the time Dawn enters orbit around Ceres in March. OR WILL THEY?


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    As Dawn spacecraft closes in on Ceres, things start to look ‘rough’

    January 28, 2015 / / 0 Comments


    Ceres: Dawn spies dwarf planet
    This image, taken 147,000 miles from Ceres by NASA's Dawn spacecraft, is part of a series of views representing the best look so far at the dwarf planet. The spacecraft is set to enter orbit March 6. (NASA)

    Eat your heart out, Hubble! NASA’s Dawn spacecraft is in the home stretch of its journey to Ceres and has snapped the best images yet of the dwarf planet. Grainy as they are, the new views of the 590-mile-wide world are already turning up unexpected features on the surface.
    “What we expect at Ceres is to be surprised, so it’s getting off to a good start,” said deputy principal investigator Carol Raymond.
    The images, taken 147,000 miles from Ceres on Jan. 25, are 30% higher-resolution than the images taken by NASA’s Hubble Space Telescope in 2003 and 2004. They measure 43 pixels wide, a significant improvement over Dawn’s images from earlier this month, which were 27 pixels across.
    The images show significant brightness and darkness variations over the surface – particularly a bright spot gleaming in the northern hemisphere and darker spots in the southern hemisphere. While the scientists were aware of those major spots, they weren’t expecting to see quite so much texture on the surface, said Raymond, a geophysicist at the Jet Propulsion Laboratory.

    Ceres is fairly warm by ice-world standards; temperatures generally range from 180 to 240 Kelvin (or minus-136 degrees Fahrenheit to minus-28 degrees Fahrenheit), Raymond said. Theoretically, the ice on Ceres’ surface should start to flow as it warms up, smoothing out any bumps such as those from impact craters. But the brightness variations across the surface make it appear very rough, she said.
    “This is just starting to illuminate the fact that Ceres is one of these unique bodies that has astrobiological potential ... and it’s just continued to become more intriguing as we’ve been marching inexorably closer,” she added.

    Ceres was not the first stop in Dawn’s 3-billion-mile journey. The first was the protoplanet Vesta, which is vastly different from its fellow mega-asteroid, Ceres. Where Vesta is dry and lumpy, Ceres is icy and round, massive enough to have been pulled into a planet-like shape. Scientists want to find out why these two space-fossils from the early solar system ended up with such different geophysical life stories.
    At least with Vesta, there were meteorites linked to the asteroid that planetary scientists can study, Raymond pointed out. For Ceres, there are no such space rocks found on Earth – so the researchers have somewhat less of an idea of what to expect.

    “I am excited,” Raymond said. “Just having had the wild ride at Vesta, I’m also just in awe of what’s going to happen. It’s going to be amazing.”

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    Gullies suggest comet Vesta once had flowing water on its surface

    January 26, 2015 / / 0 Comments



    This image of the giant asteroid Vesta was taken by NASA's Dawn spacecraft, as part of a rotation characterization sequence on July 24, 2011


    Excerpt from natmonitor.com

    NASA’s Dawn spacecraft is currently approaching the dwarf planet Ceres, the largest object in the asteroid belt that lies between Mars and Jupiter. However, from 2011 to 2013 Dawn collected extensive data on Vesta, the second largest object in the asteroid belt and one of the largest known comets in our solar system.

    The data collected from Vesta is still being analyzed and will continue to be for years to come. As the data is examined interesting new information about the giant asteroid is coming to light. Vesta which is very cold and has no atmosphere has long thought to be dry. A new study published in the journal Earth and Planetary Science Letters casts doubt on that assumption.
    While there are certainly no rivers and lakes on Vesta, photographs taken by Dawn show evidence of short lived flows of water mobilized material on the surface.

    “Nobody expected to find evidence of water on Vesta. The surface is very cold and there is no atmosphere, so any water on the surface evaporates. However, Vesta is proving to be a very interesting and complex planetary body,” said Jennifer Scully, postgraduate researcher at the University of California, Los Angeles in a statement.

    The research could change some basic assumptions in planetary science.

    “These results, and many others from the Dawn mission, show that Vesta is home to many processes that were previously thought to be exclusive to planets. We look forward to uncovering even more insights and mysteries when Dawn studies Ceres,” said UCLA’s Christopher Russell, principal investigator for the Dawn mission.
    The curved gullies on vesta are very different from what would be expected from dry material flows, say the researchers.

    “We’re not suggesting that there was a river-like flow of water. We’re suggesting a process similar to debris flows, where a small amount of water mobilizes the sandy and rocky particles into a flow. These features on Vesta share many characteristics with those formed by debris flows on Earth and Mars,“ said Scully.

    The leading theory so far is that Vesta has small patches of ice beneath the surface, possibly deposited by impacts from other comets. Later impacts could have heated the ice enough to thaw some of the water, releasing it into the crater.

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