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posted by Fnord666 on Monday October 30 2017, @07:31AM   Printer-friendly
from the surfing-a-moon dept.

Dawn Finds Possible Ancient Ocean Remnants at Ceres

Minerals containing water are widespread on Ceres, suggesting the dwarf planet may have had a global ocean in the past. What became of that ocean? Could Ceres still have liquid today? Two new studies from NASA's Dawn mission shed light on these questions.

The Dawn team found that Ceres' crust is a mixture of ice, salts and hydrated materials that were subjected to past and possibly recent geologic activity, and that this crust represents most of that ancient ocean. The second study builds off the first and suggests there is a softer, easily deformable layer beneath Ceres' rigid surface crust, which could be the signature of residual liquid left over from the ocean, too.

"More and more, we are learning that Ceres is a complex, dynamic world that may have hosted a lot of liquid water in the past, and may still have some underground," said Julie Castillo-Rogez, Dawn project scientist and co-author of the studies, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

Ceres.

Constraints on Ceres' internal structure and evolution from its shape and gravity measured by the Dawn spacecraft (open, DOI: 10.1002/2017JE005302) (DX)

The interior structure of Ceres as revealed by surface topography (DOI: 10.1016/j.epsl.2017.07.053) (DX)

Previously: Dawn Spies Magnesium Sulphate and Possible Geological Activity on Ceres
Ceres's Cryovolcanoes Viscously Relax Into Nothingness
Organic Molecules Found on Ceres
Early Asteroids May Have Been Made of Mud Rather Than Rock
Dawn Mission Extended at Ceres


Original Submission

Related Stories

Dawn Spies Magnesium Sulphate and Possible Geological Activity on Ceres 15 comments

The Dawn spacecraft has found evidence of magnesium sulphate (epsom salts) on Ceres, causing the mysterious bright spots:

The US space agency's Dawn satellite continues to return remarkable images from the dwarf planet Ceres. Now just 385km above the surface (lower than the space station is above Earth), the probe has revealed new features inside the mini-world's Occator Crater. This is the 92km-wide depression that has multiple bright spots of what are thought to be exposed salts.

[...] "The intricate geometry of the crater interior suggests geologic activity in the recent past, but we will need to complete detailed geologic mapping of the crater in order to test hypotheses for its formation." Scientists think the bright spots are deposits of epsom salts (magnesium sulphate), the trace remains of briny water-ice that at one time became exposed on the surface.

With no atmosphere on the dwarf planet, the water content would have rapidly vaporised, leaving only the magnesium sulphate spots. Ceres likely has quite a lot of buried water-ice. This idea is being investigated by the satellite's GRaND instrument, which senses neutrons and gamma rays produced by cosmic ray interactions with surface materials. It is a means to understand the chemistry of the top metre or so of Ceres' rocky "soil".

Lunar and Planetary Science Conference.


Original Submission

Ceres's Cryovolcanoes Viscously Relax Into Nothingness 3 comments

Scientists theorize that Ceres's cryovolcanoes slowly flatten over time:

A recently discovered solitary ice volcano on the dwarf planet Ceres may have some hidden older siblings, say scientists who have tested a likely way such mountains of icy rock – called cryovolcanoes – might disappear over millions of years. NASA's Dawn spacecraft discovered Ceres's 4-kilometer (2.5-mile) tall Ahuna Mons cryovolcano in 2015. Other icy worlds in our solar system, like Pluto, Europa, Triton, Charon and Titan, may also have cryovolcanoes, but Ahuna Mons is conspicuously alone on Ceres. The dwarf planet, with an orbit between Mars and Jupiter, also lies far closer to the sun than other planetary bodies where cryovolcanoes have been found.

Now, scientists show there may have been cryovolcanoes other than Ahuna Mons on Ceres millions or billions of years ago, but these cryovolcanoes may have flattened out over time and become indistinguishable from the planet's surface. They report their findings in a new paper accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.

[...] Ceres has no atmosphere, so the processes that wear down volcanoes on Earth – wind, rain and ice – aren't possible on the dwarf planet. Sori and his colleagues hypothesized that another process, called viscous relaxation, could be at work. Viscous relaxation is the idea that just about any solid will flow, given enough time. For example, a cold block of honey appears to be solid. But if given enough time, the block will flatten out until there is no sign left of the original block structure. On Earth, viscous relaxation is what makes glaciers flow, Sori explained. The process doesn't affect volcanoes on Earth because they are made of rock, but Ceres's volcanoes contain ice – making viscous relaxation possible. On Ceres, viscous relaxation could be causing older cryovolcanoes to flatten out over millions of years so they are hard to discern. Ceres's location close to the sun could make the process more pronounced, Sori said.

The vanishing cryovolcanoes of Ceres (open, DOI: 10.1002/2016GL072319) (DX)


Original Submission

Organic Molecules Found on Ceres 12 comments

Scientists using imagery from the Dawn spacecraft have found evidence of organic material on the surface of the dwarf planet Ceres:

NASA's Dawn mission has found evidence for organic material on Ceres, a dwarf planet and the largest body in the main asteroid belt between Mars and Jupiter. Scientists using the spacecraft's visible and infrared mapping spectrometer (VIR) detected the material in and around a northern-hemisphere crater called Ernutet. Organic molecules are interesting to scientists because they are necessary, though not sufficient, components of life on Earth.

[...] "This is the first clear detection of organic molecules from orbit on a main belt body," said Maria Cristina De Sanctis, lead author of the study, based at the National Institute of Astrophysics, Rome. The discovery is reported in the journal Science. Data presented in the Science paper support the idea that the organic materials are native to Ceres. The carbonates and clays previously identified on Ceres provide evidence for chemical activity in the presence of water and heat. This raises the possibility that the organics were similarly processed in a warm water-rich environment.

[...] Having completed nearly two years of observations in orbit at Ceres, Dawn is now in a highly elliptical orbit at Ceres, going from an altitude of 4,670 miles (7,520 kilometers) up to almost 5,810 miles (9,350 kilometers). On Feb. 23, it will make its way to a new altitude of around 12,400 miles (20,000 kilometers), about the height of GPS satellites above Earth, and to a different orbital plane. This will put Dawn in a position to study Ceres in a new geometry. In late spring, Dawn will view Ceres with the sun directly behind the spacecraft, such that Ceres will appear brighter than before, and perhaps reveal more clues about its nature.

Localized aliphatic organic material on the surface of Ceres (DOI: 10.1126/science.aaj2305) (DX)


Original Submission

Early Asteroids May Have Been Made of Mud Rather Than Rock 7 comments

Giant mud balls roamed the early solar system

The earliest asteroids were probably made of mud, not rock. Radioactive heat in the early solar system could have melted globs of dust and ice before they had a chance to turn to rock [open, DOI: 10.1126/sciadv.1602514] [DX], a new simulation published July 14 in Science Advances shows. The results could solve several puzzles about the composition of meteorites found on Earth and may explain why asteroids are different from comets.

[...] Bland reasoned that heat from radioactive decay would melt the ice, and the resulting body would be an enormous dollop of mud. The mud would suspend sediment particles, so they wouldn't be stripped of their sunlike elements. And it would allow the early asteroids to be any size and remain cool.

Bland and Bryan Travis of the Planetary Science Institute, who is based in Los Alamos, N.M., ran computer models of how the mud balls would evolve. Convection currents, like those that move molten rock within the Earth's mantle, would develop, helping to transfer heat into space, the models showed. After several million years, the ball would harden completely, yielding the asteroids seen today.

NASA will make a decision within the next two months on whether to extend the Dawn mission to another asteroid, leaving Ceres.


Original Submission

Dawn Mission Extended at Ceres 1 comment

The Dawn spacecraft will continue to orbit the dwarf planet Ceres, and will capture closer imagery than ever before:

NASA has authorized a second extension of the Dawn mission at Ceres, the largest object in the asteroid belt between Mars and Jupiter. During this extension, the spacecraft will descend to lower altitudes than ever before at the dwarf planet, which it has been orbiting since March 2015. The spacecraft will continue at Ceres for the remainder of its science investigation and will remain in a stable orbit indefinitely after its hydrazine fuel runs out.

The Dawn flight team is studying ways to maneuver Dawn into a new elliptical orbit, which may take the spacecraft to less than 120 miles (200 kilometers) from the surface of Ceres at closest approach. Previously, Dawn's lowest altitude was 240 miles (385 kilometers).

[...] The extended mission at Ceres additionally allows Dawn to be in orbit while the dwarf planet goes through perihelion, its closest approach to the Sun, which will occur in April 2018. At closer proximity to the Sun, more ice on Ceres' surface may turn to water vapor, which may in turn contribute to the weak transient atmosphere detected by the European Space Agency's Herschel Space Observatory before Dawn's arrival. Building on Dawn's findings, the team has hypothesized that water vapor may be produced in part from energetic particles from the Sun interacting with ice in Ceres' shallow surface. Scientists will combine data from ground-based observatories with Dawn's observations to further study these phenomena as Ceres approaches perihelion.

The Dawn spacecraft will remain in orbit at Ceres, where it is expected to operate until late 2018, without being crashed into the surface or sent to another target.


Original Submission

Mars's Oceans May Have Been Older and Shallower Than Previously Thought 4 comments

Mars' oceans formed early, possibly aided by massive volcanic eruptions

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million years earlier and were not as deep as once thought.

[...] The new model proposes that the oceans formed before or at the same time as Mars' largest volcanic feature, Tharsis, instead of after Tharsis formed 3.7 billion years ago. Because Tharsis was smaller at that time, it did not distort the planet as much as it did later, in particular the plains that cover most of the northern hemisphere and are the presumed ancient seabed. The absence of crustal deformation from Tharsis means the seas would have been shallower, holding about half the water of earlier estimates.

"The assumption was that Tharsis formed quickly and early, rather than gradually, and that the oceans came later," Manga said. "We're saying that the oceans predate and accompany the lava outpourings that made Tharsis."

It's likely, he added, that Tharsis spewed gases into the atmosphere that created a global warming or greenhouse effect that allowed liquid water to exist on the planet, and also that volcanic eruptions created channels that allowed underground water to reach the surface and fill the northern plains.

Timing of oceans on Mars from shoreline deformation (DOI: 10.1038/nature26144) (DX)

Related: Evidence of Giant Tsunami on Mars Suggests an Early Ocean
Evidence of Sea Floor Hydrothermal Deposits Found on Mars
Ceres May Have Had a Global Surface Ocean in the Past


Original Submission

Bright Areas on Ceres Suggest Geologic Activity 8 comments

Bright Areas on Ceres Suggest Geologic Activity

Since Dawn arrived in orbit at Ceres in March 2015, scientists have located more than 300 bright areas on Ceres. A new study in the journal Icarus, led by Nathan Stein, a doctoral researcher at Caltech in Pasadena, California, divides Ceres' features into four categories.

The first group of bright spots contains the most reflective material on Ceres, which is found on crater floors. The most iconic examples are in Occator Crater, which hosts two prominent bright areas. Cerealia Facula, in the center of the crater, consists of bright material covering a 6-mile-wide (10-kilometer-wide) pit, within which sits a small dome. East of the center is a collection of slightly less reflective and more diffuse features called Vinalia Faculae. All the bright material in Occator Crater is made of salt-rich material, which was likely once mixed in water. Although Cerealia Facula is the brightest area on all of Ceres, it would resemble dirty snow to the human eye.

More commonly, in the second category, bright material is found on the rims of craters, streaking down toward the floors. Impacting bodies likely exposed bright material that was already in the subsurface or had formed in a previous impact event.

Separately, in the third category, bright material can be found in the material ejected when craters were formed.

The mountain Ahuna Mons gets its own fourth category -- the one instance on Ceres where bright material is unaffiliated with any impact crater. This likely cryovolcano, a volcano formed by the gradual accumulation of thick, slowly flowing icy materials, has prominent bright streaks on its flanks.

Ceres and cryovolcanos.

The formation and evolution of bright spots on Ceres (open, DOI: 10.1016/j.icarus.2017.10.014) (DX)

Previously: A Closer Look At Mystery Spots On Dwarf Planet Ceres
NASA's Dawn Orbiter Finds a Mountain on Ceres
Ceres's Cryovolcanoes Viscously Relax Into Nothingness
Organic Molecules Found on Ceres
Dawn Mission Extended at Ceres
Ceres May Have Had a Global Surface Ocean in the Past


Original Submission

Dawn's Orbit Around Ceres: A New Low 9 comments

Previously, NASA planned to lower the closest approach to Ceres of the Dawn spacecraft to around 120 miles (200 km) from 239 miles (385 km). Now, the XMO7 orbit will reach an altitude of just 22 miles (35 km) above Ceres. The images returned should be over 9000 times better than what Hubble can capture. This is the final orbit planned:

NASA's Dawn spacecraft is maneuvering to its lowest-ever orbit for a close-up examination of the inner solar system's only dwarf planet.

In early June, Dawn will reach its new, final orbit above Ceres. Soon after, it will begin collecting images and other science data from an unprecedented vantage point. This orbit will be less than 30 miles (50 kilometers) above the surface of Ceres -- 10 times closer than the spacecraft has ever been.

Dawn will collect gamma ray and neutron spectra, which help scientists understand variations in the chemical makeup of Ceres' uppermost layer. That very low orbit also will garner some of Dawn's closest images yet.

The transfer from Dawn's previous orbit to its final one is not as simple as making a lane change. Dawn's operations team worked for months to plot the course for this second extended mission of the veteran spacecraft, which is propelled by an ion engine. Engineers mapped out more than 45,000 possible trajectories before devising a plan that will allow the best science observations.

Previously: Dawn Mission Extended at Ceres

Related: Ceres May Have Had a Global Surface Ocean in the Past
Evidence of a Seasonal Water Cycle and Surface Changes Found on Ceres


Original Submission

Dawn's Orbit Around Ceres: First Images 3 comments

The Dawn spacecraft has entered its lowest-ever orbit around Ceres:

Dawn entered orbit around 1 Ceres on March 6, 2015. Up until this year, Dawn's orbits brought it no closer than 483 kilometers (300 miles) from the rock's surface. The complicated process of entering the new 27-hour, 13-minute orbit around the asteroid began on April 16th, when NASA engineers instructed Dawn to fire its ion engines. The new orbit has a periapsis of less than 48 km above the pockmarked surface of Ceres and an apoapsis of 4,000 km.

[...] Attaining a low orbit around Ceres object is no mean feat, as the asteroid's gravitational field is lumpy due to the asteroid's uneven composition. NASA engineers looked at over 45,000 possible trajectories before settling on the solution. A lower orbit will allow researchers to map Ceres's gravitational field and hence its internal mass distribution. Surprises may be in store, though: Dawn's reaction wheels failed earlier this year, so it now uses its hydrazine-fueled thrusters to control its orientation in space.

[...] We can enjoy the final closeups of Ceres before Dawn falls silent later this year. Then, the excitement in asteroid exploration will shift towards the arrival of the Japanese Aerospace Exploration Agency's Hayabusa-2 at 162173 Ryugu this July, as well as Osiris-REX's arrival at 101955 Bennu this August.

Check out Landslides Along Occator Crater's Rim and other recent images.

162173 Ryugu and 101955 Bennu.

Previously: Dawn Mission Extended at Ceres
Dawn's Orbit Around Ceres: A New Low

Related: Ceres May Have Had a Global Surface Ocean in the Past
Evidence of a Seasonal Water Cycle and Surface Changes Found on Ceres


Original Submission

Evidence of a Seasonal Water Cycle and Surface Changes Found on Ceres 4 comments

NASA Dawn Reveals Recent Changes in Ceres' Surface

NASA's Dawn mission has found recently exposed deposits that give us new information on the materials in the crust and how they are changing, according to two papers published March 14 in Science Advances that document the new findings.

Observations obtained by the visible and infrared mapping spectrometer (VIR) on the Dawn spacecraft previously found water ice in a dozen sites on Ceres. The new study revealed the abundance of ice on the northern wall of Juling Crater, a crater 12 miles (20 kilometers) in diameter. The new observations, conducted from April through October 2016, show an increase in the amount of ice on the crater wall.

"This is the first direct detection of change on the surface of Ceres," said Andrea Raponi of the Institute of Astrophysics and Planetary Science in Rome.

[...] In a second study, VIR observations also reveal new information about the variability of Ceres' crust, and suggest recent surface changes, in the form of newly exposed material.

[...] This study, led by Giacomo Carrozzo of the Institute of Astrophysics and Planetary Science, identified 12 sites rich in sodium carbonates and examined in detail several areas of a few square miles that show where water is present as part of the carbonate structure. The study marks the first time hydrated carbonate has been found on the surface of Ceres, or any other planetary body besides Earth, giving us new information about the dwarf planet's chemical evolution.

Ceres.

Variations in the amount of water ice on Ceres' surface suggest a seasonal water cycle (open, DOI: 10.1126/sciadv.aao3757) (DX)

Nature, formation, and distribution of carbonates on Ceres (open, DOI: 10.1126/sciadv.1701645) (DX)

Previously: Ceres's Cryovolcanoes Viscously Relax Into Nothingness
Organic Molecules Found on Ceres
Ceres May Have Had a Global Surface Ocean in the Past
Bright Areas on Ceres Suggest Geologic Activity


Original Submission

Study Finds Evidence of More Organic Material on Ceres 7 comments

Organic Matter on Dwarf Planet Ceres More Abundant than Thought

A new analysis of data collected by NASA's Dawn orbiter suggests that organic molecules may exist in surprisingly high concentrations on the surface of Ceres. The study [DOI: 10.1029/2018GL077913] [DX] appears in the journal Geophysical Research Letters.

[...] To get an initial idea of how abundant those compounds might be, researchers compared the [Visible and Infrared Spectrometer] data from Ceres with lab reflectance spectra of organic material formed on Earth. Based on that standard, they concluded that 6-10% of the spectral signature they detected on Ceres could be explained by organic matter.

But for this the new study, Southwest Research Institute researcher Hannah Kaplan and co-authors wanted to re-examine those data using a different standard. Instead of relying on Earth rocks to interpret the data, they turned to an extraterrestrial source: meteorites. Some meteorites have been shown to contain organic material that's slightly different from what's commonly found on our own planet. And the new analysis shows that the spectral reflectance of the extraterrestrial organics is distinct from that of terrestrial counterparts. [...] "We estimate that as much as 40-50% of the spectral signal we see on Ceres is explained by organics. That's a huge difference compared to the 6-10% previously reported based on terrestrial organic compounds."

[...] There are two competing possibilities for where Ceres' organics may have come from. They could have been produced internally on Ceres and then exposed on the surface, or they could have been delivered to the surface by an impact from an organic-rich comet or asteroid.

Previously: Organic Molecules Found on Ceres

Related: Dawn Spies Magnesium Sulphate and Possible Geological Activity on Ceres
Ceres May Have Had a Global Surface Ocean in the Past


Original Submission

Dawn Spacecraft Runs Out of Hydrazine, Ceases Operations 13 comments

NASA's Dawn Mission to Asteroid Belt Comes to End

NASA's Dawn spacecraft has gone silent, ending a historic mission that studied time capsules from the solar system's earliest chapter.

Dawn missed scheduled communications sessions with NASA's Deep Space Network on Wednesday, Oct. 31, and Thursday, Nov. 1. After the flight team eliminated other possible causes for the missed communications, mission managers concluded that the spacecraft finally ran out of hydrazine, the fuel that enables the spacecraft to control its pointing. Dawn can no longer keep its antennae trained on Earth to communicate with mission control or turn its solar panels to the Sun to recharge.

The Dawn spacecraft launched 11 years ago to visit the two largest objects in the main asteroid belt. Currently, it's in orbit around the dwarf planet Ceres, where it will remain for decades.

Ceres, Vesta, and Dawn.

Also at Ars Technica, The Verge, and Science News.

Previously: NASA's Dawn Spacecraft Nears the End of its Mission
NASA Retires the Kepler Space Telescope after It Runs Out of Hydrazine

Related:


Original Submission

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  • (Score: 2) by c0lo on Monday October 30 2017, @07:46AM (4 children)

    by c0lo (156) Subscriber Badge on Monday October 30 2017, @07:46AM (#589366) Journal

    Some people [soylentnews.org] would go bust if alcohol isn't available, what's with this discrimination?

    (grin)

    --
    https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
    • (Score: 1, Touché) by Anonymous Coward on Monday October 30 2017, @08:04AM

      by Anonymous Coward on Monday October 30 2017, @08:04AM (#589368)

      You haven't heard of the scandal? Many alcohol products sitting on our nation's liquor store shelves are adulterated with 60%... or sometimes even as much as 96% water! ...Then there is O'Doul's.

      (smirk)

    • (Score: 2) by rylyeh on Monday October 30 2017, @08:46AM

      by rylyeh (6726) <reversethis-{moc.liamg} {ta} {htadak}> on Monday October 30 2017, @08:46AM (#589374)

      Some yeast, some sugar and Voila!

      --
      "a vast crenulate shell wherein rode the grey and awful form of primal Nodens, Lord of the Great Abyss."
    • (Score: 0) by Anonymous Coward on Monday October 30 2017, @01:05PM (1 child)

      by Anonymous Coward on Monday October 30 2017, @01:05PM (#589420)

      wait, i don't get any busts without alcohol. well, if they don't get alcohol. still

      and i discriminate amongst them because some busts are better than others, but alcohol can help provide a mountainous playing field.

      what were we talking about

      • (Score: 0) by Anonymous Coward on Monday October 30 2017, @01:24PM

        by Anonymous Coward on Monday October 30 2017, @01:24PM (#589423)

        what were we talking about

        Not weed, no

  • (Score: 2) by rylyeh on Monday October 30 2017, @08:50AM (3 children)

    by rylyeh (6726) <reversethis-{moc.liamg} {ta} {htadak}> on Monday October 30 2017, @08:50AM (#589375)

    Dell Rey's https://en.wikipedia.org/wiki/Lester_del_Rey/ [wikipedia.org] future concentrated on populating the moons of the outer planets. Engineers, right again!

    --
    "a vast crenulate shell wherein rode the grey and awful form of primal Nodens, Lord of the Great Abyss."
    • (Score: 0) by Anonymous Coward on Monday October 30 2017, @10:39AM (2 children)

      by Anonymous Coward on Monday October 30 2017, @10:39AM (#589398)
      That's no moon...
      • (Score: 0) by Anonymous Coward on Monday October 30 2017, @11:20AM (1 child)

        by Anonymous Coward on Monday October 30 2017, @11:20AM (#589404)

        Right, it's a minor planet.

  • (Score: 3, Informative) by aiwarrior on Monday October 30 2017, @03:49PM (3 children)

    by aiwarrior (1812) on Monday October 30 2017, @03:49PM (#589482) Journal

    On an interesting article, the 2 threads are off-topic and useless. One, joking about alcohol and the other about some inside joke. It is ironic we then have a post about how Instagram is the reflection of current civilization. If a site that was supposed to be for nerds cannot get better than this, than the current situation is worse than I thought.

    In the mean time I went to research Ceres, and learned that it is not a Jovian moon, but something between Mars and Jupiter, in the asteroid belt. One of things that got me curious is that it has a huge volume of water in it, which makes it yet another interesting target for human exploration. Of course the sun light is useless so I am sure that some geothermal or nuclear facilities could be arranged. One of the things that I was wandering about the other day is, who currently develops nuclear engineering for more mundane applications like RTGs and small generators? I was even dreaming of using decay as a very dense energy source that knocked out electrons and generated electricity. I digress..

    The interesting thing about Ceres and previously Europa, is that they are much more interesting planets than Mars. I would say that Mars is terribly disappointing having only the gravity as it's advantage/disadvantage. Based on my immense ignorance I find exploring Mars a waste of time and resources. With the lower gravities, these moons are much cheaper to survey and work with, plus they have active geology. Having active geology is what is believed to have created the conditions for life on Earth. Also active geology is key to understanding xeno-geology.

    There soylent. I ranted on my opinion, maybe unfounded but it is up to you to supplement, improve or discard it. At least it is on topic.

    • (Score: 2) by HiThere on Monday October 30 2017, @05:42PM

      by HiThere (866) Subscriber Badge on Monday October 30 2017, @05:42PM (#589552) Journal

      What I can't figure out is how quickly would any surface liquid water have sublimated? Even ice will evaporate when the partial pressure is low enough, so how could Ceres hold liquid water on the surface for any geologically measurable amount of time?

      My guess is that the water was internal, but that raises the question of how the minerals got to the surface. I can't believe plate tectonics, Ablation seems more plausible, but not very likely. Frost heaves?

      --
      Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
    • (Score: 4, Informative) by takyon on Monday October 30 2017, @06:37PM (1 child)

      by takyon (881) <takyonNO@SPAMsoylentnews.org> on Monday October 30 2017, @06:37PM (#589585) Journal

      https://www.google.com/search?q=site:soylentnews.org+Ceres [google.com]

      We have lots of articles on Ceres, including one 10 days ago. At some point jokes are the only thing that are going to be added unless the article proposes a mission there.

      Actually, solar power can be used at Ceres. It can be used as far as Jupiter: https://www.jpl.nasa.gov/news/news.php?feature=4818 [nasa.gov]

      The four-ton Juno spacecraft carries three 30-foot-long (9-meter) solar arrays festooned with 18,698 individual solar cells. At Earth distance from the sun, the cells have the potential to generate approximately 14 kilowatts of electricity. But transport those same rectangles of silicon and gallium arsenide to a fifth rock from the sun distance, and it's a powerfully different story.

      "Jupiter is five times farther from the sun than Earth, and the sunlight that reaches that far out packs 25 times less punch," said Rick Nybakken, Juno's project manager from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "While our massive solar arrays will be generating only 500 watts when we are at Jupiter, Juno is very efficiently designed, and it will be more than enough to get the job done."

      The Dawn mission to Ceres uses solar power: https://en.wikipedia.org/wiki/Dawn_(spacecraft)#Specifications [wikipedia.org]

      https://en.wikipedia.org/wiki/Sunlight#Intensity_in_the_Solar_System [wikipedia.org]

      45.9 W/m2 minimum for Jupiter, 715 W/m2 maximum for Mars. Ceres is somewhere in between.

      https://www.space.com/31584-dwarf-planet-ceres-colonization-the-expanse.html [space.com]

      the dwarf planet receives about 10 times less sunlight than Earth.

      "You just have to put out 10 times as many solar panels,"

      So about 2.5 more solar intensity than Juno is getting while orbiting Jupiter. Or is it?

      This page [pveducation.org], with inputs 382.62, 414.01, 445.41 (x109 meters) gives me:

      Perihelion = 382.62 x 109 m = 2.5577 AU
      197.69 W/m2

      Semi-major axis = 414.01 x 109 m = 2.7675 AU
      168.85 W/m2

      Aphelion = 445.41 x 109 m = 2.9773 AU
      145.88 W/m2

      So on average, Ceres gets a bit closer to 1/8 of the solar intensity near Earth-Moon rather than 1/10. Over three times what Jupiter gets, and Jupiter gets more like 1/27 than 1/25 what Earth gets.

      The dip when approaching aphelion could be trouble, but it is entirely possible to use a useful amount of solar power at Ceres.

      --
      [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
      • (Score: 2) by bob_super on Monday October 30 2017, @06:42PM

        by bob_super (1357) on Monday October 30 2017, @06:42PM (#589592)

        Even if you can calculate that, do not tell the odds of a spacecraft surviving a visit to a planet in an asteroid belt.

  • (Score: 3, Insightful) by bob_super on Monday October 30 2017, @06:39PM

    by bob_super (1357) on Monday October 30 2017, @06:39PM (#589589)

    > More and more, we are learning that [place we actually looked at] is a complex, dynamic world

    Funny how that seems to happen everywhere, every time we get a better look.
    Maybe, our narrow-minded astronomers (ironic given the size of what they study) should just rewrite every book about every object, starting with "we're not quite sure how yet, but it's safe to assume that billion-year-old piece of rock is probably a complex place with some interesting history"

    Next, I'm going after all those biologists assuming other animals are simple and dumb.

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