Did comets or asteroids deliver life intact to Earth? Right now, no one knows.
Astrobiologists speculate that Earth's distant past may be preserved on the Moon. We have lost our record from ancient rocks and chemical fossils on Earth which has been erased by wind, rain, and earthquakes over the last four billion years. Lunar rocks, however, may provide insight on the formation of microbial life during the early chaotic period of Earth's formation........
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