A liquid ocean under the crust of Ceres, the largest object in the asteroid belt, may have led to the formation of its cryovolcano, Ahuna Mons:
Ahuna Mons is a giant mountain with a[n] icy volcanic dome, a so-called cryovolcano. All volcanic activity for cryovolcanoes happens at low temperatures; they spew icy magma which can consist of freezing water, ammonia or methane instead of hot bubbling lava. The lack of craters on the volcano's surface meant it was probably formed quite recently – a couple of hundred million years at most. Ottaviano Ruesch, lead author of the paper and a NASA scientist working on the Dawn mission, said: "This is the only known example of a cryovolcano that potentially formed from a salty mud mix, and which formed in the geologically recent past."
The possibility of cryovolcanism on Ceres has important implications. Not only does this confirm the dwarf planet's surface temperature of minus 40°C, but it also suggests that its interior has kept warm enough for a sea of salty liquid water to exist below the planet's surface for a relatively long time. "Ceres appears differentiated internally, with a core and a complex crust made of 30 to 40 per cent water ice mixed with silicate rock and salts," said Williams.
The geomorphology of Ceres (DOI: 10.1126/science.aaf4332) (DX)
Related Stories
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.
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:
Pluto and Ceres
After Eight Years, NASA's Dawn Probe Brings Dwarf Planet Ceres Into Closest Focus
NASA's Dawn Orbiter Finds a Mountain on Ceres
Dawn Spies Magnesium Sulphate and Possible Geological Activity on Ceres
Ceres' Cryovolcano Ahuna Mons Formed in the Geologically Recent Past
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
Ceres May Have Had a Global Surface Ocean in the Past
Bright Areas on Ceres Suggest Geologic Activity
Dawn's Orbit Around Ceres: A New Low
Dawn's Orbit Around Ceres: First Images
Dawn Spacecraft Captures Closest-Ever Images of Ceres' Shiny Occator Crater
(Score: 2) by bzipitidoo on Sunday September 04 2016, @12:32AM
How can Ceres be -40? Is sunlight at Ceres orbit strong enough to warm Ceres that much? Hard to believe it could be remnant heat from formation, I'd think Ceres is too small to have any left. Radioactive elements? Seems unlikely, as most of those are heavy elements. But not impossible. Tidal heating? Can't see that one at all, it's not in a close orbit to anything, nowhere close to the Roche limit. Chemical reactions? Hard to see how that could be either, though just maybe being barely big enough to differentiate, maybe the slowness of that process on Ceres very slowly brings reactive chemicals together and that's how chemical reactions could still be generating heat after several billion years. Cosmic radiation? Well if sunlight isn't enough, how could the much weaker cosmic radiation do it? Something else? Like, that alien civilization? A fun idea, but nah.
I'm guessing it's radioactivity.
(Score: 2) by aristarchus on Sunday September 04 2016, @12:47AM
How can Ceres be -40? Is sunlight at Ceres orbit strong enough to warm Ceres that much?
Good question! -40C is a balmy February day in Calgary, Saskatchewan! But just think of the possibilities! Forty below, and what ever the appropriate equivalent of "geo-thermal" energy (asteroid-thermal?) would be to heat a space station. Wow, "Powered by cryovolcanos".
(Score: 0) by Anonymous Coward on Sunday September 04 2016, @04:05AM
Dark Warmth
(Score: 1) by khallow on Sunday September 04 2016, @04:59AM
How can Ceres be -40? Is sunlight at Ceres orbit strong enough to warm Ceres that much?
Starting with the rough estimate that the Moon has a mean temperature of 0C, Ceres is slightly darker (absorbs 5% more sunlight), heat radiates as the mean temperature to the fourth power, and closest approach (perihelion) to the Sun of 2.5577 AU, I get an estimate of the mean surface temperature of -100 C roughly. But -40C refers to the hottest areas [sciencedirect.com] rather than the mean temperature. On the Moon, the temperature has been measured up to 123C. The same calculation would yield a peak surface temperature of around -32C on Ceres.
So IMHO yes, that can be done with sunlight alone.
(Score: 2) by takyon on Sunday September 04 2016, @06:34AM
Not much radioactivity I'd assume. It is between Mars and Jupiter, but it is much closer to Mars than Jupiter (Mars = 1.38-1.67 AU, Ceres = 2.56-2.98 AU, Jupiter = 4.95-5.45 AU) Also, the Dawn orbiter will be pulled back into a higher orbit in time to see what happens when Ceres is at perihelion (and the hottest it will get):
http://www.spaceflightinsider.com/missions/higher-orbit-will-help-dawn-address-science-questions-about-ceres/ [spaceflightinsider.com]
https://en.wikipedia.org/wiki/Mars [wikipedia.org]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 1, Funny) by Anonymous Coward on Sunday September 04 2016, @09:56AM
It pains me to see you waste your efforts like this, it really does, especially since you are so inquisitive.
'Ceres', as depicted here, is pure fantasy, as is the rest of 'space' the way space agencies present it. Job-wise, I have spent a decade to this stuff, and only after I mastered geometry and calculus. I have met several of these people.
Is there wonder, awe and mystery in creation? You bet. And it is way, WAY more wonderful, awesome and mysterious that what these clowns want you to believe. The catch is that "gravity" is out of the picture, completely non-existent: hence no spinning balls, and the whole heliocentric paradigm is pure hokum.
See how a slinky free-falls, clearly pushed from above and against all gravity math. See how a gyroscope becomes 'lighter' while spinning, and completely ignores the presumed rule that it has to keep its orientation fixed relative to the fixed stars. All easy experiments to perform on your own, in this age of digital scales and high-framerate digital cameras.
Now go on, once more, and rank this post a 'Troll', a 'Flamebait' and so forth, all without investigation and out of the dogma that you have been indoctrinated with and feel the utter urge to defend. After all, the Truth sounds like hate to those who hate the Truth.
(Score: 0) by Anonymous Coward on Sunday September 04 2016, @11:53PM
There's overwhelming evidence that the Earth is round, and we're inside it.
(Score: 2) by aristarchus on Monday September 05 2016, @08:57PM
and the whole heliocentric paradigm is pure hokum.
AC: "And those fools at the Academy laughed when I presented my findings! Then they censored me! I had to move in with The Mighty Buzzard. Then he kicked me out, too, something about a Tesla coil in the bathroom, so I had to go live with khallow. But soon they will all stop laughing! Very soon, my Antigravitational Electric Universe Death Ray (AEUDR, for short) will be fully operational! That is, once I find the illudium Q-36 explosive space modulator. They will all be sorry!!"
The one fatal flaw of insane archvillains: they just can't help telling everyone about their evil plans on the internets.