A whole bunch of people want to be the first Earthlings to set foot on Mars, but they could already be too late. millions of years too late, in fact. A new theory has been floating around that the Chicxulub meteor impact (the one that killed off most of the dinosaurs) could have rocketed life-harboring Earth chunks straight onto our little red neighbor's surface.
We're not saying that ol' T. rex was smooshed flat and then shipped off to Mars to father a world of lizard people — not exactly. What scientists are suggesting is that the Chicxulub impact was large enough to send bits of rock from Earth out into the solar system to visit our celestial neighbors. Since Earth is home to a few rocks thought to have originated on the Moon, Venus, and Mars, it's easy to conceive of Earth's space-faring crust making the return trip.
Actually, a number of impacts in Earth's historical record had the oompf to send debris into space. Chicxulub in particular, however, had a good chance of dislodging rocks of the estimated ten foot diameter needed to transport life across the vacuum of space to the surface of Mars. Technically, this makes bacteria a much more likely candidate for such a trip, but some still-vital dino-DNA might have been along for the ride, so we're sticking with that idea, because it's fun to think about. Rachel Worth, the lead author of a recent paper on the subject, takes the idea of life-bearing Earth-meteors a step further:
"We find that rock capable of carrying life has likely transferred from both Earth and Mars to all of the terrestrial planets in the solar system and Jupiter. Any missions to search for life on Titan or the moons of Jupiter will have to consider whether biological material is of independent origin, or another branch in Earth’s family tree."
Published by Penn State University, the paper brings up an interesting prospect. As we go looking across the solar system for signs of alien life, we could in fact find ourselves instead — or at least some seriously distant relatives.