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andro
2010-May-27, 02:09 AM
Hey I have another ques. Can water exists on mercury:think:. In 1991 scientists at Caltech bounced radio waves off Mercury and found an unusual bright return from the north pole. The apparent brightening at the north pole could be explained by ice on or just under the surface. But is it possible for Mercury to have ice? Because Mercury's rotation is almost perpendicular to its orbital plain, the north pole always sees the sun just above the horizon. The insides of craters would never be exposed to the Sun and scientists suspect that they would remain colder than -161 C. These freezing temperatures could trap water outgassed from the planet, or ices brought to the planet from cometary impacts. These ice deposits might be covered with a layer of dust and would still show bright radar returns.

01101001
2010-May-27, 03:01 AM
Hey I have another ques. Can water exists on mercury [...]

There's probably enough data to suggest the possibility.

NASA Space Science Data Center: Ice on Mercury (http://nssdc.gsfc.nasa.gov/planetary/ice/ice_mercury.html)


How can this discovery be tested?

Direct observations of Mercury from Earth are difficult because Mercury is so close to the Sun. The only effective way to study the polar regions beyond radar observations is to send a space probe equipped with an imager and spectrometry instruments.

The MESSENGER mission (http://www.nasa.gov/mission_pages/messenger/main/index.html) should provide strong evidence one way or another. About one year to orbit insertion.

WayneFrancis
2010-May-28, 03:27 AM
To be technical...ice can...water can't.

andro
2010-May-28, 12:15 PM
why???????????

loglo
2010-May-28, 06:25 PM
No atmosphere. Ice sublimates directly to gas when heated.

catloaf
2010-May-28, 11:35 PM
Hey I have another ques. Can water exists on mercury:think:. In 1991 scientists at Caltech bounced radio waves off Mercury and found an unusual bright return from the north pole. The apparent brightening at the north pole could be explained by ice on or just under the surface. But is it possible for Mercury to have ice? Because Mercury's rotation is almost perpendicular to its orbital plain, the north pole always sees the sun just above the horizon. The insides of craters would never be exposed to the Sun and scientists suspect that they would remain colder than -161 C. These freezing temperatures could trap water outgassed from the planet, or ices brought to the planet from cometary impacts. These ice deposits might be covered with a layer of dust and would still show bright radar returns.

Can water exist on Mercury? Certainly.

Does water exist on Mercury? Probably exists as ice in shadowed craters.

Murphy
2010-May-29, 01:06 AM
Well... since we've discovered large amounts of water ice in similar dark craters on the Moon (which was previously thought to be totally dry), I think it is entirely possible on Mercury as well. But we'll have to wait and see.

WayneFrancis
2010-May-29, 04:49 AM
No atmosphere. Ice sublimates directly to gas when heated.

Exactly, I should have explained that. Sorry

Shaula
2010-May-29, 06:40 AM
One thing to bear in mind is that due to the fact that Mercury formed so close to the Sun and given that it is believed that it underwent a sort of scouring by a very hot early phase of the Sun (or a collision that stripped off most of the mantle) the amount of water left in it would be minute. Any found is more likely to have been deposited or swept up later. Outgassing is a fairly unlikely mechanism to explain any significant water deposits.

cjameshuff
2010-May-29, 03:12 PM
To be technical...ice can...water can't.

Water's water regardless of phase. Nobody asked about liquid water.



One thing to bear in mind is that due to the fact that Mercury formed so close to the Sun and given that it is believed that it underwent a sort of scouring by a very hot early phase of the Sun (or a collision that stripped off most of the mantle) the amount of water left in it would be minute. Any found is more likely to have been deposited or swept up later. Outgassing is a fairly unlikely mechanism to explain any significant water deposits.

One mechanism for some of the water is a result of solar wind protons (hydrogen ions) implanting into silicate (silicon dioxide) rocks. Over time, the solar wind hydrogen steals oxygen from the rock and forms water molecules.

This sputtering process might not account for enough water to form surface deposits, but may account for a decent portion of the "atmospheric" water vapor.

WayneFrancis
2010-May-30, 06:08 PM
Water's water regardless of phase. Nobody asked about liquid water.


People often don't ask unambiguous questions here and I was just emphasising that particular point because there will be lurkers that might read the post and think of water as in H2O in its liquid form. My answer just added information to the thread. Since the original poster used both the terms water and ice I thought I'd clarify and Andro's post #4 kind of shows even the OP might not have understood that liquid water is not possible. Sorry you found it some how offensive.