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What is the theory for how the moon was formed?

what is the evidence for the formation of the moon?

what are asteriods

where do asteroids come from and where are many of them found?

what evidence is there that asteroids have hit the earth?

what is a comet?

how does the speed of a comet changes as it gets nearer to the sun?

what are NEOs and how are they observed?

what actions could be taken to reduce the threat of NEO s

what is the big bang theory