21 Jan 2015 - Gullies on Vesta Suggest Past Water-Mobilized Flows

[NASA]

http://solarsystem.nasa.gov/missions/images/miss-dawn-mp.jpg (http://solarsystem.nasa.gov/news/display.cfm?News_ID=48664)21 Jan 2015 - Gullies on Vesta Suggest Past Water-Mobilized Flows
Protoplanet Vesta, visited by NASA's Dawn spacecraft from 2011 to 2013, was once thought to be completely dry, incapable of retaining water because of the low temperatures and pressures at its surface.


More... (http://solarsystem.nasa.gov/news/display.cfm?News_ID=48664)

[Bill Ryan]

http://solarsystem.nasa.gov/missions/images/miss-dawn-mp.jpg (http://solarsystem.nasa.gov/news/display.cfm?News_ID=48664)21 Jan 2015 - Gullies on Vesta Suggest Past Water-Mobilized Flows
Protoplanet Vesta, visited by NASA's Dawn spacecraft from 2011 to 2013, was once thought to be completely dry, incapable of retaining water because of the low temperatures and pressures at its surface.

More... (http://solarsystem.nasa.gov/news/display.cfm?News_ID=48664)

This interesting report raised my eyebrows. Vesta is one of the larger asteroids, some 500 km in diameter. But its gravity is merely 2% of the Earth's. For water to erode rock, even with sharp little particles in it, some pressure must be needed, that can only come from gravity. That tiny gravitational field just doesn't seem like enough to cause any kind of erosion at all.

Wildly guessing here, but I'm wondering if the erosion actually dates back to BEFORE whatever the h*** happened that created the asteroid belt in the first place, like a destruction of a large rocky planet.

[Limor Wolf]

Hi Bill, Is it known when the asteroid belt was created? If it was created close to the formation of the solar system than this wildly guess may not be possible. According to the article the erosion is dated to "less than a few hundred million years old", while Vesta's age is dated to 4.6 billion years.

It is interesting to learn about the various assumptions of the researchers, In the news item above it says that - "The leading theory to explain the source of the curved gullies is that Vesta has small, localized patches of ice in its subsurface. No one knows the origin of this ice, but one possibility is that ice-rich bodies, such as comets, left part of their ice deep in the subsurface following impact. A later impact would form a crater and heat up some of the ice patches, releasing water onto the walls of the crater"

I did a little research and found an article from 2012 which was published in the journal 'Nature Geoscience', where it's topic was 'water on the moon'. The researcher's assumption there was that the water did not come from a comet or other space fragments or from debris, but "are the result of "solar wind" - a stream of charged particles coming from the direction the sun and hit the moon."

In that same article (more than two years ago) the researchers also mentioned Vesta in the same context of the moon and said that "these celestial bodies have very different environments, but they all have the potential to form water."

[meat suit]

http://solarsystem.nasa.gov/missions/images/miss-dawn-mp.jpg (http://solarsystem.nasa.gov/news/display.cfm?News_ID=48664)21 Jan 2015 - Gullies on Vesta Suggest Past Water-Mobilized Flows
Protoplanet Vesta, visited by NASA's Dawn spacecraft from 2011 to 2013, was once thought to be completely dry, incapable of retaining water because of the low temperatures and pressures at its surface.

More... (http://solarsystem.nasa.gov/news/display.cfm?News_ID=48664)

This interesting report raised my eyebrows. Vesta is one of the larger asteroids, some 500 km in diameter. But its gravity is merely 2% of the Earth's. For water to erode rock, even with sharp little particles in it, some pressure must be needed, that can only come from gravity. That tiny gravitational field just doesn't seem like enough to cause any kind of erosion at all.

Wildly guessing here, but I'm wondering if the erosion actually dates back to BEFORE whatever the h*** happened that created the asteroid belt in the first place, like a destruction of a large rocky planet.

well, have a look at this,
I wouldnt be surprised if this camera eventually became eroded ...in orbit around the sun at a distance where the water would stay warm enough to be liquid... unless you need athmospheric pressure to hold it all together like in the video....??
https://www.youtube.com/watch?v=9ZEdApyi9Vw