Trying to piece together the appearance of life on Earth is a little like looking through a kaleidoscope. There are competing theories for where Earth’s water came from, and there’s incomplete evidence for how the moon formed and what role it played in life’s emergence. There are a thousand other questions, each with competing answers. Sometimes, contradictory research is published within days of each other.
Click here for original story, Asteroids are dangerous, but they might also be the key to life on Earth
Source: Phys.org