Tag Archives: Ceres

Dwarf planet Ceres is an ocean world with liquid water beneath the surface

Astronomers have called Ceres many things: the largest object in the asteroid belt; a dwarf planet; a cold, barren rock. But ‘ocean world’ is not something they would have even considered — until very recently.

This animation shows dwarf planet Ceres as seen by NASA’s Dawn. The map overlaid at right gives scientists hints about Ceres’ internal structure from gravity measurements. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Ceres lies within the asteroid belt between Mars and Jupiter. First considered to be a planet in the 19th century, it is now known to be an asteroid, and classed as a dwarf planet, like Pluto.

Now, a flurry of studies forces us to rethink Ceres once again, as astronomers report evidence indicative of a salty ocean beneath its surface.

“We can now say that Ceres is a sort of ocean world, as are some of Saturn’s and Jupiter’s moons,” Maria Cristina De Sanctis, from Rome’s Istituto Nazionale di Astrofisica and one of the study authors, told AFP.

De Sanctis and colleagues analyzed images sent from NASA’s robotic Dawn spacecraft, which entered orbit around Ceres in 2015. As Dawn approached Ceres, it offered an unprecedented glimpse into the planetoid, showing impact craters and signs of cryovolcanic activity (volcanism that erupts frozen water, ammonia, or methane, instead of molten rock). Now, researchers also analyzed infrared images, which showed the presence of a rock called hydrohalite.

A fracture system inside the rim of the Occator Crater, where the new studies found evidence of water. Image credits: NASA.

As the name implies (hydro=water, halite=rock salt), hydrohalite is a mineral that forms in salty waters and has until now only been observed on Earth. The deposit seems to have built up during the last two million years, which is extremely recent in geologic history, suggesting that the processes behind it are still very much active. In other words, it seems that brine is still ascending from the planet’s interior, a “smoking gun” for liquid water.

“That material is unstable on Ceres’ surface, and hence must have been emplaced very recently,” said co-authors Julie Castillo-Rogez, from the California Institute of Technology’s Jet Propulsion Laboratory.

Another published paper found evidence of cryovolcanism that started around 9 million years ago and lasted for several million years, also indicative of a deep brine source. Gravity data and thermal modeling also imply an extensive deep brine reservoir beneath the Ceresian surface.

A crater on Ceres in enhanced color. Image credits: NASA.

In a separate paper, researchers used remote sensing to analyze the crust of Ceres, finding evidence of density and rheological variations, which are also consistent with a liquid ocean under the surface. Whether or not this is still an active ocean or just a remnant of one is unclear.

This finding could have massive implication for the field of astrobiology. Not only does Ceres (a seemingly dull object in the asteroid belt) feature liquid water beneath its surface, shielded from radiation — but it also features salt.

According to De Sanctis, the ingredients of life seem to be lining up nicely on Ceres.

“The material found on Ceres is extremely important in terms of astrobiology,” she said.

“We know that these minerals are all essential for the emergence of life.”

Journal References:

  • C. A. Raymond et al. Impact-driven mobilization of deep crustal brines on dwarf planet Ceres, Nature Astronomy (2020). DOI: 10.1038/s41550-020-1168-2
  • A. Nathues et al. Recent cryovolcanic activity at Occator crater on Ceres, Nature Astronomy (2020). DOI: 10.1038/s41550-020-1146-8
  • R. S. Park et al. Evidence of non-uniform crust of Ceres from Dawn’s high-resolution gravity data, Nature Astronomy (2020). DOI: 10.1038/s41550-020-1019-1
  • M. C. De Sanctis et al. Fresh emplacement of hydrated sodium chloride on Ceres from ascending salty fluids, Nature Astronomy (2020). DOI: 10.1038/s41550-020-1138-8
  • B. E. Schmidt et al. Post-impact cryo-hydrologic formation of small mounds and hills in Ceres’s Occator crater, Nature Geoscience (2020). DOI: 10.1038/s41561-020-0581-6
A simulated perspective of Ahuna Mons. Credit: NASA/JPL-CALTECH/UCLA/MPS/DLR/IDA/PSI

Volcanoes on dwarf planet ooze ice instead of molten lava

A simulated perspective of Ahuna Mons. Credit: NASA/JPL-CALTECH/UCLA/MPS/DLR/IDA/PSI

A simulated perspective of Ahuna Mons. Credit: NASA/JPL-CALTECH/UCLA/MPS/DLR/IDA/PSI

The dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter. It’s also one of the most interesting cosmic bodies in the area, with studies showing it may have water-vapor plumes and even a subsurface ocean. Now, new research shows that the dwarf planet’s geology is even more fascinating than meets the eye. Apparently, volcanoes have been erupting on the surface of Ceres for the past billion years. But these aren’t your typical volcanoes — instead of explosively spewing lava, they gently ooze ice!

The ice volcanoes

Ceres, which stretches only 965 km (600 miles) across, was first spotted on Jan. 1, 1801 by Sicilian astronomer Giuseppe Piazzi.  At first, Ceres was called a planet, but as more asteroid belt members were discovered, the cosmic object was demoted to an asteroid status. Its status changed again in 2006 when it was promoted to a dwarf planet — a classification it shares with Pluto.

In 2015, NASA’s Dawn mission discovered a huge volcano on the surface of Ceres. Called Ahuna Mons, the volcano measures 19 km (12 miles) at its base and stands 4.8 km (3 miles) tall. All its features suggested that Ahuna Mons was a young volcano, no older than 200 million years. This was downright perplexing to scientists, seeing how Ceres is geologically dead. Volcanic activity in the inner solar system generally wanes over time as the interior of a body cools, as is the case on Venus, Mars, and Earth’s moon. Why would a 4.5-billion-year-old Ceres suddenly become volcanically active?

Ahuna Mons, of course, is not your typical volcano. It’s what scientists call a cryovolcano — a volcano that erupts icy material instead of molten lava. Cryovolcanism can be spotted elsewhere on the moons Enceladus, Europa, and Triton, and perhaps on many other worlds in the outer solar system. These eruptions are likely powered by the bodies’ internal heat and make for some of the best places to search for life beyond Earth because they expel material buried from potentially life-friendly reservoirs below the surface.

Now, a team of researchers led by Michael Sori of the University of Arizona found that Ahuna Mons is not alone. By studying topographic maps captured by Dawn, the researchers found 32 large domes measuring more than 6.2 miles in diameter, which they suspected may be volcanoes. They eventually settled on 22 domes that suggest cryovolcanic activity, all of them estimated to be less than a billion years old.

Ceres. Credit: NASA/Jet Propulsion Laboratory.

Ceres. Credit: NASA/Jet Propulsion Laboratory.

According to the researchers, it’s likely that Ceres has grown a new cryovolcano every 50 million years, on average. These findings help to explain some of the dwarf planet’s puzzling features, showing, for instance, that Ahuna Mons is not the only cryovolcanic construct on Ceres but rather one of many. The results also suggest that although Ceres has been continually cryovolcanic for the past billion years, the amount of eruptive activity is actually but a fraction of what geologists typically see on Earth (100,000 times less volume), much less even than has occurred on Mars and Venus.

In addition to being less productive, the volcanic eruptions on Ceres are also much tamer than those on Earth. Instead of violent eruptions of ash, plume, and lava, cryovolcanoes simply ooze out cryomagma — a salty mix of rocks, ice, and other volatiles such as ammonia — which freezes on the surface.

The causes themselves of cryovolcanic eruptions on Ceres are still a mystery but future research could come up with an explanation as more probes visit other bodies in the solar system.

Scientific reference: Cryovolcanic rates on Ceres revealed by topography, Nature Astronomy (2018). DOI: 10.1038/s41550-018-0574-1. 

Ceres organic matter.

New analysis reveals that Ceres’ spots harbor a lot of organic material

New research shows Ceres’ surface is dotted with organic matter — much more of it that we’ve previously realized. The findings raise questions regarding how this material came to be, and why it concentrates in patches.

Ceres organic matter.

Spots of organic material near Ernutet crater on the dwarf planet Ceres.
Credit: NASA / Hannah Kaplan.

There seems to be more to the organic material the Dawn craft discovered on Ceres last year than we initially thought. The patches of carbon-based compounds may contain a much higher abundance of organic matter than initial analysis revealed, according to a new analysis from Brown University.

Organic, free-range Ceres

“What this paper shows is that you can get really different results depending upon the type of organic material you use to compare with and interpret the Ceres data,” said Hannah Kaplan, lead researcher of the study. “That’s important not only for Ceres, but also for missions that will soon explore asteroids that may also contain organic material.”

The discovery of these organic patches on Ceres last year was made using the Visible and Infrared (VIR) Spectrometer on the Dawn spacecraft, which has been in orbit of the dwarf planet since 2015. The finding was met with enthusiasm at NASA and beyond: organic molecules are, after all, the building blocks of life. So, scientists are understandably keen on finding out how such matter is distributed on planets other than our own. The presence of these compounds on Ceres isn’t proof that there was once life on this bit of rock. However, it definitely increases the odds. Factor in that Ceres also boasts a sizeable stash of water ice, another fundamental requirement for life as we know it, and you get quite the exciting place.

The picture may get even better, however. Dawn’s VIR instrument analyzed the patches on Ceres’ surface using the way its surface interacts with incoming light. By looking at what wavelengths these patches reflected and absorbed, ground control could estimate their chemical makeup. In the region of Ernutet Crater (Ceres’ northern hemisphere), Dawn picked up signals consistent with organic molecules. Next, NASA needed to know just how much organic material they had found — so they compared the VIR data to similar readings performed on samples of organic material from Earth. Based on this comparison, they concluded that Ceres’ spots comprised roughly 10% organic matter.

Kaplan and her team, however, weren’t satisfied with the reference standard NASA used — so they re-did the comparison using a different one. Instead of using Earth-borne rocks, they used samples of carbonaceous chondrite meteorites. Previous analysis of such space rocks that fell to Earth revealed that they contained organic material that is slightly different from that native to our planet.

“What we find is that if we model the Ceres data using extraterrestrial organics, which may be a more appropriate analog than those found on Earth, then we need a lot more organic matter on Ceres to explain the strength of the spectral absorption that we see there,” Kaplan said.

“We estimate that as much as 40 to 50 percent of the spectral signal we see on Ceres is explained by organics. That’s a huge difference compared to the six to 10 percent previously reported based on terrestrial organic compounds.”

Unknown origin

The team proposes two possible explanations for how organic material popped up on Ceres in such high concentrations. They could either have been produced on Ceres itself and then blasted to the surface. Alternatively, they could have been delivered by impacts with organic-rich comets or asteroids.

In the case of delivery, comets are more likely culprits than asteroids — the former tend to have higher contents of organic material, around 40 to 50 percent, which would be consistent with Ceres’ patches. However, this explanation seems unlikely, the team notes. The violence and heat of these impacts would likely destroy a substantial amount of the original organic material, meaning we’d see much lower concentrations on the surface.

The other explanation, that of in-situ generation, is also problematic. Organic material has only been identified in small patches on Ceres’ northern hemisphere — and, if the team’s findings are correct, in high concentrations. It’s a lot of organic material spread over a very small area, and we have no idea how it could get like this.

“If the organics are made on Ceres, then you likely still need a mechanism to concentrate it in these specific locations or at least to preserve it in these spots,” said Ralph Milliken, a study co-author.

“It’s not clear what that mechanism might be. Ceres is clearly a fascinating object, and understanding the story and origin of organics in these spots and elsewhere on Ceres will likely require future missions that can analyze or return samples.”

It’s not all unanswered questions. The research will help improve our ability to analyze the chemical make-up of extraterrestrial bodies. The team hopes their findings will “provide a framework of how to better interpret data of asteroids and make links between spacecraft observations and samples in our meteorite collection.”

With NASA announcing that it discovered organic material on Mars just one week ago, it seems that the universe may be a much more organic place than we’d assumed.

The paper “New Constraints on the Abundance and Composition of Organic Matter on Ceres” has been published in the journal Geophysical Research Letters.

Ceres, the largest object in the asteroid belt is still ‘evolving’

Astronomers found evidence that compounds on Ceres formed from liquid water in the recent geologic past.

Distribution and intensity of the carbonate absorption in VIR data. Image credit: Carrozzo et al., Sci. Adv. 2018;4: e1701645

In a way, Ceres is both big and small. It’s the largest object in the asteroid belt, but it’s still a dwarf planet — and it’s much too small to be really considered a planet. About four times smaller than the moon, Ceres has a diameter of approximately 945 kilometers. It was first discovered in 1801 by Giuseppe Piazzi and considered a planet, but was then relegated to asteroid status. But this doesn’t mean that Ceres isn’t exciting in its own right.

The NASA spacecraft Dawn entered orbit around Ceres on 6 March 2015, allowing astronomers to study it in unprecedented detail. In a new study, authors report that Ceres is still evolving.

Using the visible-infrared mapping spectrometer aboard Dawn, they observed significant quantities of magnesium-calcium carbonates covering most of the dwarf planet. Finding carbonates — a salt of carbonic acid (H2CO3) — is extremely important since it is usually a sign of water. Judging by the current analysis, astronomers now believe water amounts to about 30% of the dwarf planet’s mass.

Carbonates are abundant and ubiquitous across the surface, but variations in the strength and position of infrared spectral absorptions indicate variations in the composition and amount of these minerals. Also, not all carbonates are hydrated, and therefore not all of them can be connected to water.

Some carbonate patches featured sodium carbonate in its hydrated form — which is a clear indication of liquid water. Pictured is the distribution of water ice (left), sodium carbonate (center) and hydrated sodium carbonate (right) in a crater on Ceres. Credits: Carozzo et al.

Ceres appears to have differentiated rocky core and an icy mantle. Researchers have known for quite a while that Ceres probably had liquid water in its recent history (and perhaps still has), but the wide distribution of carbonates, and therefore, the water, is surprising.

“The different chemical forms of the sodium carbonate, their fresh appearance, morphological settings, and the uneven distribution on Ceres indicate that the formation, exposure, dehydration, and destruction processes of carbonates are recurrent and continuous in recent geological time, implying a still-evolving body and modern processes involving fluid water,” the researchers write.

Patches of hydrated sodium carbonate (green and red) were found around craters with domes or mounds by the team. Image credits: Carozzo et al.

The authors suggest that the connection between carbonates and extrusive surfaces implies that carbonates are possibly brought to the surface by rising subsurface fluids. This could indicate that beneath a frozen surface, there is an ocean of liquid water. The carbonate mapping indicates active geological processes such as upwelling, excavation, and exposure of salts.

Ceres doesn’t get nearly as much love as Pluto does, but given recent findings, perhaps it should.

The study has been published in Science AdvancesDOI: 10.1126/sciadv.1701645

More surprises on Ceres: astronomers discover an ice volcano

Pictures from NASA’s Dawn spacecraft seem to indicate that the dwarf planet was much more active than we thought.

There is probably an ice volcano on Ceres. Image color indicates elevation. Image via NASA.

Ceres is the largest body in the asteroid belt – too big to really be an asteroid, but too small to be a planet, it’s trapped in the “minor planet” classification. But Ceres might be much more interesting than other similar bodies, with its mysterious bright spots being a constant source of amazement. In October 2015, observations revealed white patches on Ceres’ surface, which researchers initially presumed to be ice and then turned out to be salt.

“When we got to Ceres, we were expecting to be surprised, and we have been in many ways,” Dawn principal investigator Chris Russell, a professor of geophysics and space physics at the University of California, Los Angeles (UCLA), told Space.com.

This time, astronomers found something which may very well be an ice volcano – a planetary pimple called Ahuna Mons. The mountain protrudes in an otherwise smooth terrain, it is not an impact feature, and it appears to be the only mountain of its kind on Ceres. Bright streaks run top to bottom on its slopes.

“This is an amazing construct and a huge mountain,” Christopher Russell told Gizmodo. “It’s nothing like a terrestrial ice mound we’ve ever seen.”

For a volcano, it would be pretty big. It is estimated to have an average height of about 4 km (2 mi) and a maximum height of about 5 km (3 mi), or 16,000 feet, on its steepest side; it is about 20 km (12 mi) wide at the base. But why do people think it’s a volcano anyway – and an ice volcano at that?

NASA’s Dawn probe captured this high-resolution image of the Ceres mountain Ahuna Mons. Image width is 19 miles (30 kilometers).
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Well, it’s mostly because we don’t have a better explanation. We’ve previously observed ice volcanoes on bodies like Saturn’s moon Enceladus. When the temperature becomes low enough (as is the case on Enceladus and Ceres), “classical volcanoes” can’t exist, and any volcanic phenomenon is manifested through ice.

“In the outer solar system, we never see classic volcanoes because the temperatures are so low,” explains Ottaviano Ruesch of the Goddard Spaceflight Center, who analyzed the images of Ahuna Mons. “Instead, we have salty water ice. At the right temperatures, that material can become molten and rise to the surface.”

There is strong evidence that it isn’t an impact feature, and it’s instead something that comes from within.

“Ceres has been active during its history inside; the interior has been changing, evolving, much like the Earth’s interior changes with time,” added Russell, lead author of one of the new Science papers and co-author on the other five. “It’s in the transition between the smaller asteroids and the Earth, in that it changes, and has changed, over the years from the time that the material initially came together.”

But not everyone is sold on the ice volcano theory. Jeffrey Moore, head of the Geology and Geophysics Imaging Team for the New Horizons mission, has a lot of experience with this kind of features, after analyzing several features on Pluto which look a lot like ice volcanoes.

“It’s an intriguing hypothesis that it is a volcano, and it’s hard to explain without a volcano, but in my view it’s not conclusive,” Moore told Gizmodo. “If Ahuna Mons had more unambiguous flow features coming out of the volcano and down the slope, or a more conspicuous central depression, I think it’d be an easier sell.”

Whether it’s an ice volcano or not, we know it happened relatively recently. Ahuna Mons is just a few hundred million years old, whereas Ceres has a 4.5 billion year history. Further information will hopefully enable us to properly understand this geological feature.

NASA’s Dawn mission reveals Ceres craters that can trap water ice

Ceres contains shadowy regions that may be cold enough to trap water ice for up to a billion years, according to a new study.

Image credits NASA/JPL

New data from NASA’s Dawn mission has revealed the presence of craters on Ceres that exist in permanently shadowed regions of the dwarf planet. Due to the low temperatures of these areas, scientists believe that these regions could hold ice deposits that stem from water ice that has remained trapped for approximately one billion years

“The conditions on Ceres are right for accumulating deposits of water ice,” said Norbert Schorghofer, a researcher from the University of Hawaii at Manoa and first author of the study. “Ceres has just enough mass to hold on to water molecules, and the permanently shadowed regions we identified are extremely cold – colder than most that exist on the moon or Mercury.”

The regions of Ceres subject to permanent shadow are craters that are not exposed to direct sunlight. Typically, these areas are located along crater floors or sections of their walls that face toward the pole. Although these regions are still subject to indirect sunlight exposure, when temperatures remain below minus 151 degrees Celsius they become a prime location for the stable accumulation of water ice – also known as a cold trap.

Schorghofer and his team made their findings through the examination of Ceres’ northern hemisphere, which was chosen due to its more favorable illumination conditions compared to the south. NASA’s Dawn cameras revealed Ceres’ craters, plains and other unique features in three dimensions.

In combination with computer modeling, the data was used to reveal the presence of numerous shadowed regions across the northern hemisphere, with the largest located inside a 10-mile-wide crater.

Due to the distance of Ceres from the sun, the permanently shadowed regions outlined in the new study are suggested to be colder than those on Mercury or the moon.

“On Ceres, these regions act as cold traps down to relatively low latitudes,” said Erwan Mazarico, a Dawn guest investigator at NASA’s Goddard Space Flight Center and co-author of the study. “On the moon and Mercury, only the permanently shadowed regions very close to the poles get cold enough for ice to be stable on the surface.”

Although Ceres’ permanently shadowed regions take up less than one percent of the surface area of its northern hemisphere, approximately one in every 1,000 water molecules created on its surface will end up in a cold trap during any given year on the dwarf planet. Over the period of around 100,00 years, these cold traps could lead to the creation of thin but detectable ice deposits.

“While cold traps may provide surface deposits of water ice as have been seen at the moon and Mercury, Ceres may have been formed with a relatively greater reservoir of water,” said Chris Russell of the University of California, Los Angeles and first author of the study. “Some observations indicate Ceres may be a volatile-rich world that is not dependent on current-day external sources.”

Journal Reference: The permanently shadowed regions of dwarf planet Ceres. Published 6 July 2016. 10.1002/2016GL069368

NASA reveals two new spectacular photos of Ceres

NASA released a new set of images of Ceres – and they’re a sight to behold.

A false-color image of Haulani Crater shows evidence of recent landslides. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The pictures were taken by the Dawn spacecraft, a space probe launched by NASA in 2007 to study Vesta and Ceres. After spending time around Vesta and revealing a trove of valuable information about it, Dawn is now orbiting Ceres already providing some surprises.

“Ceres continues to amaze, yet puzzle us, as we examine our multitude of images, spectra and now energetic particle bursts,” said Chris Russell, Dawn principal investigator at the University of California, Los Angeles.

The image above is of the Haulani Crater, a surprisingly bright impact crater on Ceres. It was taken when Dawn was still in its high-altitude mapping orbit, about 1,480 kilometers (920 miles) above Ceres. Spectacular as this image is, it was made to look even better. The image has been color enhanced, and the blueish streak you see is not the natural color of the crater.

“Haulani perfectly displays the properties we would expect from a fresh impact into the surface of Ceres. The crater floor is largely free of impacts, and it contrasts sharply in color from older parts of the surface,” said Dr. Martin Hoffmann of the Max Planck Institute for Solar System Research, Germany, in a statement.

Oxo Crater with the “slump” to the bottom right. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

Another intriguing picture was snapped of the Oxo Crater, the second brightest feature on Ceres. Minerals on the bottom of this crater appear to be different than on the rest of the protoplanet, and astronomers want to study it in more detail in the future.

Bright spots on Ceres are signs of geological activity

Ceres is the largest body in the asteroid belt – too big to really be an asteroid, but too small to be a planet, it’s trapped in the “minor planet” classification. But Ceres might be much more interesting than other similar bodies, with its mysterious bright spots being a constant source of amazement.

The bright spots on Ceres from different angles.

We’ve written about the bright spots on Ceres before and how we don’t really know what they are. An informal NASA poll during May offered the following ideas for the nature of the spots: ice, volcanos, geysers, salt deposits, rock, or other.

New and very precise observations using the HARPS spectrograph at the ESO 3.6-metre telescope at La Silla, Chile, have revealed not only the rotation of these spots due to Ceres rotating around its own axis, but also unexpected variations which indicate that the spots are volatile and evaporate in sunlight. Ceres spins every nine hours and the velocities to and away from the Earth caused by this rotation are very small, but still large enough to be measurable via the Doppler effect with high-precision instruments such as HARPS.

The lead author of the new study, Paolo Molaro, at the INAF-Trieste Astronomical Observatory, explains:

“As soon as the Dawn spacecraft revealed the mysterious bright spots on the surface of Ceres, I immediately thought of the possible measurable effects from Earth. As Ceres rotates the spots approach the Earth and then recede again, which affects the spectrum of the reflected sunlight arriving at Earth.”

It only took two nights of observation from HARPS. The measurements were made in July and August in 2015, but were only now interpreted.

“The result was a surprise,” adds Antonino Lanza, at the INAF-Catania Astrophysical Observatory and co-author of the study. “We did find the expected changes to the spectrum from the rotation of Ceres, but with considerable other variations from night to night.”

The team now believes that whatever the substance within the bright spots may be, it is volatile enough to evaporate when exposed to sunlight. This effect, however, changes from night to night, giving rise to additional random patterns, on both short and longer timescales. If this is the case, then Ceres would be very different from other similar bodies like Ceres, and still geologically active. Ceres is known to be rich in water, but it is unclear whether this is related to the bright spots.

The energy source that drives this continual leakage of material from the surface is also unknown.

NASA continues to reveal insights about Ceres

At the European Planetary Science Conference in Nantes, France, NASA presented some spectacular maps and observations about Ceres, the largest object in the asteroid belt, and the largest of the minor planets within the orbit of Neptune. Astronomers analyzed data coming from the Dawn spacecraft, which entered orbit around Ceres on 6 March 2015.

This view, made using images taken by NASA’s Dawn spacecraft, is a color-coded topographic map of Occator crater on Ceres. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

“Ceres continues to amaze, yet puzzle us, as we examine our multitude of images, spectra and now energetic particle bursts,” said Chris Russell, Dawn principal investigator at the University of California, Los Angeles.

This color-coded map from NASA’s Dawn mission shows the highs and lows of topography on the surface of dwarf planet Ceres – basically a topography map. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

For starters, NASA revealed tantalizing (false-color) maps of Ceres which definitely stole the show in Nantes. The maps highlight the compositional differences present on the surface, especially a puzzling, cone-shaped 4-mile-high (6-kilometer-high) mountain which is still an enigma. The mountain, which is now referred to as the Lonely Mountain, was found back in April, and while several theories have been proposed, no satisfying answer has stood out. Dawn’s chief investigator Christopher Russell said:

“We’re having difficulty understanding what made that mountain and we have been getting many suggestions from the public.”

The peculiar shapes of the craters on Ceres are also surprising.

“The irregular shapes of craters on Ceres are especially interesting, resembling craters we see on Saturn’s icy moon Rhea,” said Carol Raymond, Dawn’s deputy principal investigator based at NASA’s Jet Propulsion Laboratory, Pasadena, California. “They are very different from the bowl-shaped craters on Vesta.” Vesta is another large planetoid in the area.

Another unexpected observation was the data coming from the gamma ray and neutron spectrometer on Dawn. The instrument detected three bursts of energetic electrons – these may result from the interaction between Ceres and the Sun’s radiation, but that’s also not confirmed.

“This is a very unexpected observation for which we are now testing hypotheses,” Russell said.

Observations made on Ceres suggest that it has a differentiated body, a rocky core overlain with an icy mantle. This 100-kilometer-thick mantle (23%–28% of Ceres by mass) contains up to 200 million cubic kilometers of water, which would be more than the amount of fresh water on Earth. This result is supported by the observations made by the Keck telescope in 2002 and by evolutionary modeling, and Dawn observations are also consistent.

Dawn became the firsts mission to ever reach a dwarf planet, arriving at the planetoid on March 6, 2015, after it conducted measurements on March 6, 2015. Currently, Dawn is orbiting Ceres at an altitude of 915 miles (1,470 kilometers); it will conduct several full orbits, each of which will last 11 days.

 

ceres bright spots

Mysterious bright spots on dwarf-planet Ceres imaged in detail by NASA spacecraft

NASA’s spacecraft Dawn is currently orbiting Ceres – a dwarf planet and the largest object in the asteroid belt – in order to study this highly fascinating, yet enigmatic object. For instance, strange and peculiar brights spots on its surface are still puzzling scientists. NASA has kindly shared some of the photos documenting these brights spots, taken by Dawn from only 2,700 miles above the surface.

ceres bright spots

Image: NASA

When these bright spots were first spotted by NASA researchers, everybody was amazed. All indications point to a volcano-like origin of the spots, but no one could tell for sure until the spacecraft came closer. Even at 2,700 miles away, things aren’t clear yet what these spots, each about 6 miles wide nestled inside giant craters up to 50 miles wide, are supposed to be or how they formed.

Ceres bright spots

Image: NASA

 

What’s certain is that the eight spots that have spotted so far are made up of some kind of reflective material, either ice or salt. Maybe even glass formed by impacts, considering all the spots are found inside craters.  No alien cities I’m afraid.

“The surface of Ceres has revealed many interesting and unique features. For example, icy moons in the outer solar system have craters with central pits, but on Ceres central pits in large craters are much more common. These and other features will allow us to understand the inner structure of Ceres that we cannot sense directly,” Carol Raymond, deputy principal investigator for the JPL-based Dawn mission, said in the release.

Another interesting feature is a large, mountain-like peak that stands five miles high. That’s peculiar considering the rest of the dwarf planet’s surface is virtually flat. We’ll know more for certain once Ceres descends to a lower orbit.

“Dawn is the first mission to visit a dwarf planet, and the first to orbit two distinct targets in our solar system. It arrived at Ceres, the largest object in the main asteroid belt between Mars and Jupiter, on March 6, 2015,” read NASA’s release. “Dawn will remain in its current altitude until June 30, continuing to take images and spectra of Ceres in orbits of about three days each. It then will move into its next orbit at an altitude of 900 miles (1,450 kilometers), arriving in early August.”

Ceres bright spots

Image: NASA

Dwarf Planet Ceres reveals its colors, but keeps its secrets

NASA’s Dawn spacecraft already has an impressive resume – it’s traveled to the asteroid belt and managed to start orbiting the dwarf planet Ceres, even though Ceres measures only 950 kilometers (590 miles) in diameter and has a very small gravitational field. But it’s not stopping just yet – after previously revealing a number of black and white pictures, Dawn has now provided a color photograph, but here’s the thing – it poses more questions than it answers.

Infrared images suggest that Spot 1 (top row), an area on Ceres, is made of ice. But the pair of bright gleams known as Spot 5 were invisible to an infrared camera (bottom right). Image credits: NASA/JPL-Caltech/UCLA/ASI/INAF

Ceres is the largest object in the asteroid belt between Mars and Jupiter. It comprises of rock and ice, and despite its small size (it’s about as big as Argentina), it is considered to be a dwarf planet (though some astronomers consider it an asteroid). Subsequently, it’s drawn quite a lot of scientific interest, and Hubble first looked at it a few years ago; but it wasn’t until the Dawn spacecraft actually started orbiting it that we got a really good look at it.

“This is the first idea of what the surface looks like,” said Martin Hoffmann, a Dawn scientist from the Max Planck Institute for Solar System Research in Göttingen, Germany.

Dawn took several tantalizing pictures of bright spots on Ceres, which might be the result of some active geology – something extremely exciting. In total, astronomers noticed 5 particular spots which they are trying to figure out.

The surface of the dwarf planet Ceres (shown here) has fewer large craters than researchers expected. Image credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

But could a celestial body so small actually have proper geology? Some scientists have speculated that one of the spots could be linked to an icy plume – a feature of so-called ‘cryovolcanoes’, volcanoes that spew ice and water instead of magma and ash. Finding such a small and yet active body is intriguing to say the least, but for now, Ceres is still keeping its secrets. We don’t know for sure what those spots are, how they were created, whether or not there is active geology or even whether frozen volcanoes actually exist.

“Dawn took its most recent set of images on 10 April, but only a small fraction of Ceres’s surface was illuminated at the time and mission scientists have not yet released them. The spacecraft will begin detailed science investigations on 23 April, after it settles into permanent orbit around Ceres,” Nature writes.

Dawn will near Ceres even more and take even more revealing, hopefully helping unravel the secrets that Ceres is hiding. The fact that we can get up-close and personal with something that’s so small and 400 million km away is absolutely mind blowing to me

Dawn spacecraft will soon figure out what Ceres actually is

NASA’s Dawn spacecraft has set sail to Ceres – one of the most intriguing objects in our solar system. Ceres is the largest object in the asteroid belt between Mars and Jupiter, containing a third of all the mass in the asteroid belt. The unmanned Dawn spacecraft is scheduled to arrive at Ceres in early 2015, and will hopefully shed provide new insights not only on Ceres itself, but also the asteroid belt and the solar system.

Ceres as seen by Hubble Space Telescope (ACS). The contrast has been enhanced to reveal surface details.

The asteroid belt is a very accurate name – it represents the place between  the orbits of the planets Mars and Jupiter, occupied by numerous irregular bodies, called asteroids. But among all these asteroids, Ceres alone is considered a dwarf planet – an object the size of a planet (a planetary-mass object) but that is neither a planet nor a moon or other natural satellite. Ceres has a diameter of about 950 km, and to put it bluntly… we don’t really know what it is.

Ceres is probably a surviving protoplanet (planetary embryo), which formed 4.57 billion years ago in the asteroid belt – this is the main theory. In 2014, Ceres was found to have an atmosphere with water vapor, confirmed by the Herschel space telescope, which adds even more mystery to Ceres. Vesta, the second largest object in the asteroid belt is also a point of interest.

“These two bodies are much more massive than any body yet visited in this region of space and are truly small planets,” the Dawn mission team, at NASA’s Jet Propulsion Laboratory (JPL), wrote in their mission statement.

Studying these objects could also tell us more about our solar system – no matter what’s there, it’s almost certainly unchanged since the early days of the planetary formation.

Ceres (bottom left), the Moon and the Earth, shown to scale. Image via Wiki Commons.

“When Dawn visits Ceres and Vesta, the spacecraft steps us back in solar system time,” the JPL team said.

In 2007, Dawn paid a short visit to Vesta, and found a dry and metallic wasteland. Astronauts are expecting quite a different story with Ceres – maybe even some water under the icy surface, though that’s highly debatable. Whatever it is, the good thing is that we’ll have a chance to study.

“Now, finally, we have a spacecraft on the verge of unveiling this mysterious, alien world,” Marc Rayman, chief engineer and mission director of the Dawn mission, said in a statement. “Soon it will reveal myriad secrets Ceres has held since the dawn of the solar system.”

Water found on dwarf planet Ceres may erupt from ice volcanoes

It takes the form of vapor plumes erupting into space and the theory the scientists have agreed upon is that the main cause could be the ice geysers on the planet surface functioning similarly to volcanoes. The scientific explanation of the fact is detailed in the journal Nature on January 22, where it is explained as a result of the orbit bringing the planet so close to the sun to partly melt its surface, mostly covered with ice. The amount of water the scientists believe it produces is shockingly large.

While the first hypothesis on the vapor formation is icy volcanic activity, another possibility would be the sublimation of the ice near the surface, or turning directly from solid to gas, pulling along with it dust from the surface, similarly to comets.

One of the scientists conducting the researching program declared that ‘This is the first time water vapor has been unequivocally detected on Ceres or any other object in the asteroid belt and provides proof that Ceres has an icy surface and an atmosphere’. Michael Kuppers is an active member of the IAU (International Astronomy Union) in benefit of the European Space Agency. Pluto (formerly classified as a fully recognized planet), Eris, Haumea and Makemake are, along with Ceres, part of the IAU lists other dwarf planets orbiting the sun beyond Neptune, out of which only Ceres is known to exist in the asteroid belt.

Ceres is either a dwarf planet or a giant asteroid, depending on the definitions followed, nevertheless the largest object in the asteroid belt. Its framing stated Ceres was believed to be a large asteroid, when, in 2006, the International Astronomical Union reclassified it as a dwarf planet because of its very large size. Ceres is orbiting at 2.8 astronomical units, approximately the distance from Earth to the sun, while its diameter has 950 kilometers of a rocky interior, covered with a compact ice layer. A comparison has been made by the scientists, who believe that by melting its entire quantity of ice the water resulted would actually be a larger amount than all the water we have on Earth.

The scientific community suspected that there existed ice on Ceres, but it was only after using technologies such as the Herschel space telescope or the heterodyne instrument for the far-infrared in researching procedures when a clear spectral signature of water vapors was identified without doubt. And while the astrologists were used to blasting plumes of gas and vapor from comets – mostly because of their icy structure), nobody really expected similar behavior from an object residing in an asteroid belt.

This perspective view of Marcia crater on the giant asteroid Vesta shows the most spectacularly preserved example of "pitted terrain," an unexpected discovery in data returned by NASA's Dawn mission. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/JHUAPL

Hints of water found on the giant space rock Vesta

Two studies conducted by scientists at NASA based on data gathered by the Dawn spacecraft, which orbited around the Vesta asteroid, showed that the giant space rock holds tantalizing signs of water on its surface – albeit in very small amounts, in the form of hydrated minerals.

This perspective view of Marcia crater on the giant asteroid Vesta shows the most spectacularly preserved example of "pitted terrain," an unexpected discovery in data returned by NASA's Dawn mission. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/JHUAPL

This perspective view of Marcia crater on the giant asteroid Vesta shows the most spectacularly preserved example of “pitted terrain,” an unexpected discovery in data returned by NASA’s Dawn mission. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/JHUAPL

These conclusions were drawn after scientists found that volatile, or easily evaporated materials, have colored Vesta’s surface in a broad swath around its equator. Again, concerning its geometry,  peculiar pothole-like features mark some of the asteroid’s surface where the volatiles, likely water, released from hydrated minerals boiled off and eroded the rock. These formations have been found to be extremely similar to those on Mars, however while the planet is known to have been abundant  in water at a time; these feature identified on Vesta, an asteroid, took scientists particularly by surprise.

Again, no actual water was found, but scientists explain that due to the high energy release during collisions with other space rocks, the hydrogen bound to the minerals was converted into water, which instantly evaporated and thus geologically shaped the asteroid. The holes that were left as the water escaped stretch as much as 0.6 miles (1 kilometer) across and go down as deep as 700 feet (200 meters).

“The source of the hydrogen within Vesta’s surface appears to be hydrated minerals delivered by carbon-rich space rocks that collided with Vesta at speeds slow enough to preserve their volatile content,” said Thomas Prettyman, the lead scientist for Dawn’s gamma ray and neutron detector (GRaND) at the Planetary Science Institute in Tucson, Ariz.

At first, the researchers hypothesized that it might be possible for ice water to survive on the surface of the asteroid, at its poles. However,  Vesta has no permanently shadowed polar regions where ice might survive, and is permanently exposed to sunlight in a cyclic fashion.

“These results provide evidence that not only were hydrated materials present, but they played an important role in shaping the asteroid’s geology and the surface we see today.”

The Dawn spacecraft left last month from Vesta’s orbit, which is the 2nd largest rock in the asteroid belt, and is currently heading for the dwarf planet of Ceres – the biggest rock in the asteroid belt.

The findings were described in two papers published in the journal Science.

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NASA’s Dawn spaceship departs Vesta asteroid, heads for Ceres

It’s one asteroid down and one to go, for NASA’s Dawn spacecraft. After spending a year studying the Vesta asteroid and retrieving valuable information to Earth, Dawn is now ready to head for its next destination: Ceres.

A different world

Scientists expect Ceres to be very different from Vesta. Ceres is considered to be the largest asteroid in our solar system, accounting for about a third of all the mass in the asteroid belt; in fact, it is a dwarf planet (the only one in the inner system), discovered more than 200 years ago, in 1801 – however, it was thought to be a full sized planet at the moment.

Ceres highlights a rocky inner core, and an icy mantle, and many believe it might hold a liquid ocean beneath the icy surface. The 100 km mantle has more freshwater than the Earth, and while exobiologists haven’t speculated on this matter as much as with Europa, for example, there is a possibility of life existing in the liquid water – if there is such a thing on Ceres.

Leaving Vesta

Vesta is a large asteroid too, the second largest one in our solar system, after Ceres, of course, with a mean diameter of about 525 kilometers; among its notable features, there lies a mountain about three times taller than Mount Everest. After spending one year on Vesta, Dawn slowly powered up its ion thrusters, slowly spiraling away from it after it can finally break free from the gravitational field. However, since its antenna has been pointed away from Earth, researchers have to wait until Wednesday to know if everything went according to plan – pretty much like with the ‘seven minutes of terror‘, for Curiosity. Still, it’s not the same thing.

“It’s not a sudden event. There’s no whiplash-inducing maneuver. There’s no tension, no anxiety,” said chief engineer Marc Rayman of the NASA Jet Propulsion Laboratory, which manages the $466 million mission. “It’s all very gentle and very graceful.”

A new Dawn

The Dawn shuttle is about to reach a historical landmark, if it succeeds in its three year trip: it will become the first shuttle to ‘hook up’ with two different celestial bodies – in a bid to learn more about our solar system’s evolution, and the asteroids themselves.

During its one year stay at Vesta, Dawn was quite busy, using its cameras, infrared spectrometer, gamma ray and neutron detector to explore the asteroid from different altitudes, getting as close as 209 kilometers from its surface; and it wasn’t in vain: Dawn revealed quite a few surprises.

Scientists have long known Vesta is scarred at its southern pole, likely from an impact with a smaller asteroid, but a closer inspection revealed Vesta has another scar pretty close to the first one – evidence that it has been hit twice by asteroids in the last 2 billion years. The collision threw shrapnel like pieces of rock into outer space, some of them actually landing on Earth as meteorites.

Asteroids – friend and foe

Asteroids have been given a lot of attention lately – for varied reasons. There is of course the always present fear that some naughty asteroid might head for our planet and whack us to oblivion – though now NASA keeps track of virtually all near-Earth asteroids, and even with today’s technology, there are ways to deflect an asteroid.

President Barack Obama canceled a return to the moon in favor of landing astronauts on a yet-to-be-selected asteroid as a stepping stone to Mars, and perhaps even more interesting – a number of tech billionaires are planning to mine asteroids for rare metals (gold, platinum, iridium, etc).

Researchers expect a much changed story on Ceres. Unlike the rocky Vesta, the nearly spherical Ceres has a dusty surface with an icy interior.

“Almost everything we see at Ceres will be a surprise and totally different from Vesta,” Russell said.

Via NASA’s Jet Propulsion Laboratory

Hubble Space Telescope images of Vesta and Ceres show two of the most massive asteroids in the asteroid belt, a region between Mars and Jupiter. Credits for Vesta: NASA, ESA, and L. McFadden (University of Maryland) Credits for Ceres: NASA, ESA, and J. Parker (Southwest Research Institute)

NASA spacecraft set to visit giant asteroid this weekend

Hubble Space Telescope images of Vesta and Ceres show two of the most massive asteroids in the asteroid belt, a region between Mars and Jupiter. Credits for Vesta: NASA, ESA, and L. McFadden (University of Maryland) Credits for Ceres: NASA, ESA, and J. Parker (Southwest Research Institute)

Hubble Space Telescope images of Vesta and Ceres show two of the most massive asteroids in the asteroid belt, a region between Mars and Jupiter. Credits for Vesta: NASA, ESA, and L. McFadden (University of Maryland) Credits for Ceres: NASA, ESA, and J. Parker (Southwest Research Institute)

After a four year journey, NASA’s Dawn spacecraft will finally reach the orbit of Vesta, the second largest asteroid in our solar system.

The object, located 117 million miles from Earth and spanning across a circumference of 329 miles, will be visited in premiere by Dawn this weekend when the latter will hover over on July 16. For whoever’s interested, the exact time is 1:00 a.m. EDT.

“It has taken nearly four years to get to this point,” said Dawn project manager Robert Mase of NASA’s Jet Propulsion Laboratory in a press release. “Our latest tests and check-outs show that Dawn is right on target and performing normally.”

The target in question is located in an asteroid- rich filled zone, in between the  solar system’s inner and outer planets. Propulsion and navigation had been powered by Mars’ gravitational force and Dawn’s own ion-powered thrusters. Once the spaceship reaches Dawn, it’s scheduled to hover about 9,900 miles above the asteroid’s surface for a whole year and, in this time, use two different cameras, a gamma-ray detector and a neutron detector to study and map the object. After this part of the mission is over, next July, Down’s ion thrusters will catapult the spaceship out of orbit and towards the dwarf planet Ceres, the largest object in the Asteroid Belt.

Meanwhile, NASA has another asteroid mission running, spearhead by the Osiris-Rex spacecraft, which is supposed to land and collect samples from a near-Earth asteroid, before returning home to Houston by 2023.

Very little is know about both Vesta and Ceres, although a lot of theories are currently emitting suppositions. Vesta maybe once had a molten core before going cold after a few million years, while Ceres, some believe, may have an icy mantle and active mud volcanoes.

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