# Prehistoric Earth and Mars?

**URL:** <https://boards.straightdope.com/t/prehistoric-earth-and-mars/131340>\
**Category:** Factual Questions\
**Created:** [October 8, 2002, 12:44pm UTC](https://boards.straightdope.com/t/prehistoric-earth-and-mars/131340 "2002-10-08T12:44:30Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Earthworm\_Jim](https://avatars.discourse-cdn.com/v4/letter/e/f07891/32.png) [@Earthworm\_Jim](https://boards.straightdope.com/u/Earthworm_Jim)\
**Post date:** [October 8, 2002, 12:44pm UTC](https://boards.straightdope.com/t/prehistoric-earth-and-mars/131340/1 "2002-10-08T12:44:30Z")

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If I understand things correctly (a big if), Mars was pretty well formed about 10 - 30 million years after the formation of the solar system (myafss). About 70 - 100myafss the Earth was struck by a mars-sized object, resulting in the moon. My questions are: How long did it take the earth to ‘recover’ from this? Also, I recall reading that in most models two moons resulted, one of which crashed back to earth - what would the result of that impact be? Finally, what was the state of Mars during this time frame - or, was there ever a time in the history of the solar system when mars was warm and wet, but the earth was not?

Thank you all 🙂