PDA

View Full Version : A mechanism for a formation of a extremely dry Gaian planet?



m1omg
2007-Oct-23, 07:33 PM
My idea;
If the Moon forming impact was a bit bigger, the Earth would lose almost all of it's water (not all, some will remain and also later cometary impacts will bring some).There will be some deep underground aquifers and shallow saline seas, and life will evolve there.The atmosphere will be the same as previously but almost all CO2 present previously would be boiled to space along with water, so runaway greenhouse would be impossible.An atmosphere with a pressure of a few bars would remain.Eventually, photosynthetic life will evolve.The result will be a living world but with extremely arid enviroment and so life would be adapted to these conditions and became multicellular or even sapient.

If such worlds can exist, what would be the likely adaptations of lifeforms on it?

antoniseb
2007-Oct-23, 07:40 PM
My idea;
If the Moon forming impact was a bit bigger, the Earth would lose almost all of it's water (not all, some will remain and also later cometary impacts will bring some)...
Alternatively, a second event such as that that formed the moon, but *after* the major bombardment period would probably have left the Earth with no water near the surface, and little but Carbon-Dioxide and Argon in the atmosphere.

RalofTyr
2007-Oct-23, 08:22 PM
Maybe something like this?

http://www.worlddreambank.org/S/SERRANA.HTM


Without the fox-people...


I imagin any worlds orbiting Alpha Centauri A would be rather dry as Alpha Centauri B would have absorbed a lot of the comets.

Kaptain K
2007-Oct-24, 03:18 AM
The Moon forming impact occurred very early. The Earth was still collecting loose planetoids. It was still molten or semi-molten rock. There was no water (at least in liquid or solid form).