Submission + - Was Earth a Migratory Planet? (discovery.com)
astroengine writes: "Why our planet isn't a "snowball Earth" — a dilemma called the "faint young sun paradox" — has foxed solar and planetary scientists for decades. Since the Earth's formation, a planet covered in ice should have stifled any kind of greenhouse effect, preventing our atmosphere from warming up and maintaining water in a liquid state. Now, David Minton of Purdue University has come up with a novel solution that, by his own admission, straddles science fact and fiction. Perhaps Earth evolved closer to the Sun and through some gravitational effect, it was pushed to a higher orbit as the Sun grew hotter. But watch out, if this is true, planetary chaos awaits."
