We've heard about lots of big plans for the Moon: mining colonies, space tourism, science outposts, observatories, even art installations. But now we might be able to add "fossil park." New research suggests that fossils dislodged from Earth could have hit the lunar surface — and remained intact.
Mark Burchell, a professor of space science at the University of Kent, led the study, which simulated the conditions that fossilized diatoms— microscopic algae with detailed shells— might have faced if travelling from the Earth to the Moon.
This would have been a tough journey. The typical scenario would involve two extreme shock events. The first would occur when a giant object—say an asteroid— impacted the Earth and threw up high-speed ejecta, which would then escape into space. The second, more extreme shock would occur when, after a period of traveling in space, the terrestrial rock would make a violent arrival at its new home, impacting the Moon at speeds as high as 3 kilometers per second.
Burchell's research team turned fossil-filled rock into powder, which they then mixed with water and froze to replicate meteoroids. The icy samples were then fired into a bag of water—at speeds between 0.4 and 5 kilometers per second— using a large gas-powered gun that simulated the impact of being launched into orbit. The high pressure that the samples experienced as they hit the water roughly duplicated the conditions of hitting the lunar surface.
The scientists found that the higher the speed, the more fragmented the fossils. But, some of those fragments could still be recognized as biological in origin, and the smaller fossils could survive intact at speeds slightly higher than 5 kilometers per second. (See left: Images a, b, c show intact diatoms; d, e, f show fragments).
The conclusion: Rocks on the Moon might contain fossilized life forms from Earth's distant past. All we need to do now is go up there and look for them.