The new discovery of water on Mars has certainly increased
interest/discussion in life on Mars. For years I've been wondering how
Earth got all of its water. We take it for granted, but where did it come
from? I teach astronomy, and books often mentioned that at least some of
our water came from comets. Makes sense.
I was flipping channels tonight and came across How The Universe Works
("The First Oceans" episode) on The Science Channel. It portrayed the
three ways Earth got its water -- from asteroids/meteorites, from Earth
itself, and from Jupiter! The show said that Jupiter, in the very young
solar system, was closer to the Sun and attracted lighter/colder
particles, which were redirected toward the Earth. This was the primary
method the Earth its water. I learn something new every day!
But will we every really understand how the Earth got so wet?