Can Bacteria Survive Space Vacuum, UV?

Porfiry of ExoScience writes: "The theory that microbial life once came to Earth on a meteorite from another planet will be tested on July 26 when a NASA rocket carries into space special microorganisms from research at the University of Maryland Biotechnology Institute (UMBI). The tiny space pioneers will be riding an apogee, or suborbital, flight path similar to the historic 1961 flight of astronaut Alan Shepard. The passengers this time will be four dime-size cultures, each holding about 100 million cells of the microbes that will be exposed to space vacuum and solar radiation for 10 minutes."

Comments

Surviving in space is one thing, but...

[KFury]

Surviving in a hard vacuum and radiation is one thing, but surviving a re-entry into the Earth's atmosphere is quite another.

Not to mention the state the artifact must have been in when it was ejected from Mars in the first place. As I understand it, the theory is that significant meteor strikes on Mars can propel martian fragments outside of its gravity well. From all I've read about meteor strikes on Earth, any 'shrapnel' from a blast that large is molten rock when it ejects.

So the real question is: Can microbial life survive a molten host environment, then frozen, irradiated, and exposed to a hard vacuum (the microbes on the exterior, that is), then heated to near-molten levels again when it reenters the atmosphere? If so, we'd better not go to Io!

Kevin Fox

bacteria survived apollo moon mission

[Benjamin Shniper]

http://www.science.nasa.gov/newhome/headlines/ast0 1sep98_1.htm

Many have referred to it; here it is from a reliable source. Or as reliable as you get on the internet.

-Ben

Re:What's the point?

[Chalst]

I read a fascinating article about how these bacteria are supposed to
survive high doses of radiation: the ionising radiation is so
energetic it will actually sever any DNA it encounters, but the
bacteria is able to reassemble the original DNA from fragments.
Reported in the recent Economist survey on the Genome project.

Maybe it IS the right test

[laborit]

I was briefly annoyed when I saw this article, but fortunately the scientists were smarter than the blurb made them sound. Of course throwing some random bacteria into space won't prove anything about the long-term space-endurance of their entire form of life. Bacteria, thanks to their rudimentary life-support needs and short generations, can undergo some truly striking mutations. The extremophiles are a group of bacteria that have evolved to live in ridiculously inhospitable extremes of heat, cold, and toxicity. Some species grow optimally at >100C and pH1.0 -- a hundred times more acidic than stomach acid and hot enough to boil water! In fact, the project appears to be using something similar, a bacterium which was discovered in an extremely hot geothermal spring.

Even then, Earth bacteria aren't necessarily going to have the right stuff. Bacteria that evolved on a planed without a magnetic field to block harmful high-energy particles and an ozone layer to absorb UV might have tolerances to radiation that would be stupidly excessive for anything in our relatively lax biosphere. Like bacteria from our own poles, life from a very cold planet might have a metabolism slow enough that traveling through space for 10,000 years wouldn't be a big problem (and if not, we always have spores). If you had some bacteria initially living on the interior of a chunk of ground that became a meteor, it's even conceivable that they could gradually evolve specifically to survive on the surface of a spacefaring rock.

If this fails, biologists might turn to trying to engineer bacteria that can survive in space. Creating selection pressure for radiation, vacuum, etc. isn't so hard...

- Michael Cohn