|
Written by Michael Mascha
|
|
Thursday, 02 November 2006 00:00 |
|
Ours is the blue planet, and the hallmark of life on Earth is water. But where did this colorless, odorless liquid first come from?
Recent discoveries in astrophysics suggest that water is not native to Earth but rather was imported from the edges of our solar system as ice trapped in comets. Scientists think this water was first delivered here more than four billion years ago. During the meteor shower that gave the Moon most of its craters, Earth received five hundred times more "hits" than its moon did; since the planet has a greater critical mass than its satellite, Earth was also able to hold on to much of the water from the ice.
|
|
Last Updated ( Sunday, 29 March 2009 16:53 )
|
|
Read more...
|