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View Full Version : The Fate of the Moon's Atmosphere?



RalofTyr
2008-Mar-28, 05:47 AM
The Moon did have an atmosphere at one time. After the collision, massive volcanism was present on the Moon, so, how long did the atmosphere stick around? Was it as massive as Venus'?


Seconldy, the Moon had to have been struck with many comets as Earth. Where did the water go? Could there not be underground reserves of water on the Moon?

Also, have we found any evidence of running water on the Moon? A dry riverbed and such?

m1omg
2008-Mar-28, 12:19 PM
The Moon did have an atmosphere at one time. After the collision, massive volcanism was present on the Moon, so, how long did the atmosphere stick around? Was it as massive as Venus'?


Seconldy, the Moon had to have been struck with many comets as Earth. Where did the water go? Could there not be underground reserves of water on the Moon?

Also, have we found any evidence of running water on the Moon? A dry riverbed and such?

Earth has only a fraction of it's water from comets and Moon was not massive enough to retain much water, simply, it evaporated into space except maybe for some ice on the bottom of craters in enternal shadow.

No dry riverbeds.

01101001
2008-Mar-28, 02:46 PM
Neil deGrasse Tyson: Water, Water (http://research.amnh.org/~tyson/18magazines_water.php)


Starting in the solar system, if you seek a waterless, airless place to visit then you needn't look farther than Earth's Moon. Water swiftly evaporates in the Moon's near-zero atmospheric pressure and its two-week-long, 200 degree Fahrenheit days. During the two-week night, the temperature can drop to 250 degrees below zero, a condition that would freeze practically anything.

[...] Recent evidence from the Clementine lunar orbiter strongly supports a long-held contention that there may be frozen lakes lurking at the bottom of deep craters near the Moon's north and south poles. Assuming the Moon suffers an average number of impacts per year from interplanetary flotsam, then the mixture of impactors should include sizable water-rich comets. How big? The solar system contains plenty of comets that, when melted, could make a puddle the size of lake Erie.

While one wouldn't expect a freshly laid lake to survive many sun-baked lunar days at 200 degrees, any comet that happened to crash in the bottom of a deep crater near the poles (or happened to make a deep polar crater itself), would remain in darkness because deep craters near the poles are the only places on the Moon where the "Sun don't shine."

mugaliens
2008-Mar-29, 02:49 PM
Actually, the Moon does have an atmosphere (http://en.wikipedia.org/wiki/Atmosphere_of_the_Moon), as do all bodies with any sort of gravitational pull.

Not much of one, though! It keeps getting ripped by solar winds.

darkdrag0nlq
2008-Mar-29, 06:10 PM
I'm pretty sure the moons atmosphere is only out 1-2 inches from the surface.

Grashtel
2008-Mar-30, 12:23 PM
I'm pretty sure the moons atmosphere is only out 1-2 inches from the surface.
Definitely not, the weaker a body's gravitational field the further its atmosphere extends, so the Moon's atmosphere probably extends further than Earth's (assuming that the effects of the solar wind don't tear it away before that). On the other hand a neutron star's atmosphere does extend only a couple of feet from its surface because of its enormous gravitational field.