LIFE on Earth may have begun on Mars, a team of researchers told the American Astronomical Society meeting in Atlanta this week.
Collisions could have blasted life-containing rocks off Mars into space, so if life evolved there it probably reached the early Earth. Life appeared so early on Earth that some scientists in the past have suggested it must have evolved first on another planet outside the Solar System.
But the researchers rule out any source outside the Solar System. “The problem for interstellar transfer is the long transit time,” said Jay Melosh of the University of Arizona. Radiation would…
