DNA survives fiery heat of re-entry on test rocket
Life came here by meteorite theory gets a boost
Sounding rockets are sub-orbital spacecraft used to test rocket technologies and to run other experiments. Launches of such craft are quite common and most escape attention: the TEXUS-49 mission launched from Sweden on March 29th, 2011, and now doesn't even produce a clean hit on Google.
But the mission is now of rather considerable interest, because as this Plos.One paper explains, “artificial plasmid DNA carrying a fluorescent marker … was attached on different positions of rocket exterior”.
The rocket's trajectory saw it ascend to an altitude of about 270km and experience six minutes of microgravity. On the way down, things got nasty: the paper says “Temperature measurements showed two major peaks at 118 and 130°C during the 780 seconds lasting flight on the inside of the recovery module, while outer gas temperatures of more than 1000°C were estimated on the sample application locations.”
Yet the DNA aboard not only survived, but was later able to reproduce after elaborate tests involving petri dishes, agar, bacteria and lots of shaking it all about.
“We were able to demonstrate experimentally that plasmid DNA attached to the outer surface of the payload of a sounding rocket can withstand a period of residence in space and the re-entry conditions into the Earth atmosphere as well as the landing, and stays intact and active in its function as carrier of genetic information,” the paper reports.
But the paper stops short of saying the results reported are a big tick for the “life arrived on meteorites” theory, as the authors point out they've only tested one part of that theory. Whether micro-organisms or DNA could survive the many other exigencies they would face on an interstellar journey remains unknown. ®