I've never heard a theory that the moon itself impacted the Earth. There has been discussion of the idea of a fast glancing blow by Theia, which is omitted: ht

I've never heard a theory that the moon itself impacted the Earth. There has been discussion of the idea of a fast glancing blow by Theia, which is omitted: http://www.bbc.com/news/science-environment-19011013 http://www.bbc.com/news/science-environment-19011013