Have you ever wondered if life on Earth could have been seeded by extra-terrestrials?  Findings of a recent study suggest that this may, indeed, have taken place.  This phenomenon, called lithopanspermia, is the transfer of micro-organisms between meteors or planetoids that collide in outer space.

Until recently, notions about the gravity and velocity of matter in space suggested that there were very few collisions between two objects. For this reason, lithopanspermia was not a viable hypothesis. In the new study, scientists considered asteroid speeds up to 50 times slower than before. These speeds, they believe, would have occurred when bits of matter fell into orbit around massive, stationary star clusters. These orbiting meteors and planetoids would have only been partly captured in the star’s gravitational field. As a result, they would remain subject to the gravitational pull of other passing bodies. These weak and wobbly orbits increased the chances of impact between two passing objects. The study concluded that collisions may have been frequent enough to warrant further inquiry.

The next step was to cross-reference the other assumptions we hold about the development of the solar system, and see if lithopanspermia was compatible. Based on a comprehensive list of other data, including the capacity for life to survive on meteors, the age of the sun, and the changing habitat on earth, the study concluded the following:

"So, if life arose on Earth shortly after surface water was available, there were possibly about 400 million years when life could have journeyed from the Earth to another habitable world, and vice versa, the researchers report. If life had an early start in other planetary systems and developed before the sun's birth cluster dispersed, life on Earth may have originated beyond our solar system."

While this may still be a far cry from colonization by intelligent extra-terrestrial entities, these findings reinforce a perception of the early universe as an interconnected whole.  Changes and developments in one region of space could ripple and percolate through the network of stars and planets. Studies like this one help to quietly initiate a more expansive and inclusive perception of the universe beyond Earth.


Image by
Smithsonian Institution, courtesy of Creative Commons licensing.