Did life sprout on distant planets and crash to Earth?
(Phys.org)—Microorganisms that crashed to Earth embedded in the fragments of distant planets might have been the sprouts of life on this one, according to new research from Princeton University, the University of Arizona and the Centro de Astrobiología (CAB) in Spain. The researchers report in the journal Astrobiology that under certain conditions there is a high probability that life came to Earth—or spread from Earth to other planets—during the solar system's infancy when Earth and its planetary neighbors orbiting other stars would have been close enough to each other to exchange lots of solid material. The work will be presented at the 2012 European Planetary Science Congress on Sept. 25. The findings provide the strongest support yet for "lithopanspermia," the idea that basic life forms are distributed throughout the universe via meteorite-like planetary fragments cast forth by disruptions such as volcanic eruptions and collisions with other matter. Eventually, another planetary system's gravity traps these roaming rocks, which can result in a mingling that transfers any living cargo. Read more here.