Planetary scientists still consider the theory of panspermia, in which life can naturally transfer between planets, a serious hypothesis.
New research presented at the European Planetary Science Congress at UCL is aiming to answer the final question, of whether entry and impact being survivable for simple organisms.
Using frozen samples of Nannochloropsis oculata, a type of single-celled ocean-dwelling algae, Dina Pasini (University of Kent) set out to test the conditions which early life would have had to survive if it did indeed travel through space.
Using a two-stage light gas gun, which can accelerate objects up to very high speeds, Pasini fired frozen pellets of Nannochloropsis into water and tested the samples to see if any had survived.
Pasini said that as people might expect, raising the speed of impact does increase the proportion of algae that die but even at 6.93 kilometers per second, a small proportion survived.
She said that this sort of impact velocity might be expected if a meteorite hit a planet similar to the Earth. Ice and rocks can provide protection against radiation, especially if the organism is deeply embedded inside.
This research suggests that panspermia, while certainly not proven, is not impossible either.