The Moon forming impact (4.5 Gyr) occurred ~100 million years after Earth's formation. The earliest solid grain comes from another ~100 million years after that (4.4 Gyr). The earliest signs of life (4.1 Gyr) are from ~300 million years after the earliest grain. Does not seem implausible that life could have arisen during the first 100 million years as well. We know very little about that era since the impact liquified the whole surface.
There's been some research from my alma mater that it might have had water even that early [1]. I haven't seen good data on the estimated temperature during this time (it was hot certainly, the question would be how frequently were there pockets where hyperthermophiles would be able survive). I like this paper's approach [2] - they end up with a small chance of life before the impact.
Comments
The Moon forming impact (4.5 Gyr) occurred ~100 million years after Earth's formation. The earliest solid grain comes from another ~100 million years after that (4.4 Gyr). The earliest signs of life (4.1 Gyr) are from ~300 million years after the earliest grain. Does not seem implausible that life could have arisen during the first 100 million years as well. We know very little about that era since the impact liquified the whole surface.
Ah ok, didn’t know the moon formed that quickly, thank you for your detailed answer, very interesting :)
Wouldn’t the (pre Moon) Earth have been pretty hot after formation and probably no water either?
There's been some research from my alma mater that it might have had water even that early [1]. I haven't seen good data on the estimated temperature during this time (it was hot certainly, the question would be how frequently were there pockets where hyperthermophiles would be able survive). I like this paper's approach [2] - they end up with a small chance of life before the impact.
[1] https://archive.is/NZwpJ
[2] https://www.liebertpub.com/doi/pdf/10.1089/ast.2005.5.154