Science Forums 2

[Turtle]

Originally Posted by Prolu2007

I always thought it came from huge meteorite impacts, and as far as I understand it's from two sources Primary Water and Water from Comets.

... However, in Earths First Billion years and over the past 4.5 billion years, the main source of water was from comets.

The water-from-comets idea is now passee.

Originally Posted by NASA

PASADENA -- A new Caltech study of comet Hale-Bopp suggests that comets did not give Earth its water, contrary to the longstanding belief of many planetary scientists.

http://www2.jpl.nasa.gov/comet/news98.html

Originally Posted by findarticle.com

Taken together with the signatures of volatiles on Earth, these data suggest that no more than 50 percent, and probably less than 15 percent, of Earth's water could have been added from space at the end of our planet's formation, says Drake.

http://www.findarticles.com/p/articl..._84546023/pg_1