This week, DNA carried on a flight through space and back to Earth was found to remain, for the most part, intact and capable of passing on genetic information. The results were published following an experiment on a TEXUS-49 research rocket mission ran by a team from the University of Zurich.
These incredible results were obtained by applying small, double-stranded DNA molecules onto the outer shell of the payload section of the rocket. Following the launch, space flight and re-entry, the plasmid DNA could still be found on each of the application points. Even more astonishing was the discovery that much of the salvaged DNA remained able to transfer genetic information to bacterial and connective tissue cells. The experiment was originally conceived as a test to check the stability of biomarkers during spaceflight and re-entry – meaning the results were all the more unexpected.
The findings have some exciting consequences for our understanding of DNA. Study leader Professor Oliver Ullrich believes the results indicate that ‘DNA’s genetic information is essentially capable of surviving the extreme conditions of space and the re-entry into Earth’s dense atmosphere.’ The inference of this is that organic molecules could potentially spread between planetary bodies through meteor impacts. Around 100 tons of extra-terrestrial material hits Earth each day, a fact that has led some scientists to believe that DNA could reach our planet from space.
Whatever the implications of these findings, they also act as a caution for future space missions, most particularly the search for extra-terrestrial life. The surprising stability of DNA presents a lot of opportunity for contamination. It is very plausible that space ships could carry terrestrial DNA to their target sites.