Protecting the Solar System From Contamination 121
tcd004 writes "An article at PBS begins, 'Imagine this crazy scenario: A space vehicle we've sent to a distant planet to search for life touches down in an icy area. The heat from the spacecraft's internal power system warms the ice, and water forms below the landing gear of the craft. And on the landing gear is something found on every surface on planet Earth... bacteria. Lots of them. If those spore-forming bacteria found themselves in a moist environment with a temperature range they could tolerate, they might just make themselves at home and thrive and then, well... the extraterrestrial life that we'd been searching for might just turn out to be Earth life we introduced.' The article goes on to talk about NASA's efforts to prevent situations like this. It's a job for the Office of Planetary Protection. They give some examples, including the procedure for sterilizing the Curiosity Rover: 'Pieces of equipment that could tolerate high heat were subjected to temperatures of 230 to 295 degrees Fahrenheit for up to 144 hours. And surfaces were wiped down with alcohol and tested regularly.'"
Re:Office Of Planetary Protection? (Score:5, Informative)
I'm so glad we put so much effort into protecting other planets.
Now how about we stop tossing radioactive shit all over our own? kthx.
I don't think that's NASA's department. You'd have to talk to the Department of Energy to ask them to stop letting coal plants emit so much radioactive waste products if your goal is to limit radiation release.
Re:Already done (Score:5, Informative)
Actually, you should read up on the topic before you go spouting nonsense.
Transfer of Life-Bearing Meteorites from Earth to Other Planets [arxiv.org] for example.
Re:alcohol? doesn't kill them all (Score:5, Informative)
Re:Already done (Score:5, Informative)
As my handle suggests, I am a research biologist. Mostly, that just means I like to think about this sort of topic. Don't take it as me attempting to shut you or others down.
Your logic is more or less on the ball... DNA isn't made of amino acids. There are plenty of other nitrogenous bases which could have been used in DNA without any other complications. The paired bases do have to match up in a consistent way. Various forms of synthetic DNA has been made with alternate bases and it seems to behave like DNA in a physical sense.
I too prefer to think that the bases our DNA use has do do with which ones were most readily available, or which were most available in the little puddle where the biosystem started. Those basic organisms which started later or used things 'almost as good' got eaten in the endgame.
Similar logic comes in to play with the amino acids which we use to make proteins. There are many alternatives, several of which have been experimentally introduced into living biosystems. (There are E.coli which now use amino acids not found in any natural biological system; labs at University of Texas-Austin study this topic.) With amino acids, there is even more room for random chance in the initial choise of basic modules. Once that first living system started, it probably ate every other nascent living system. There is good reason to believe that amino acids will be used to form proteins and that a certain diversity of amino acids is needed, covering several basic chemistries, but that the specific amino acids isn't so important. (The E.coli types with chemically novel amino acids grow just fine.)