This is incredible. Apparently, that Mars meteorite that hit us some 13,000 years ago contains biogenic magnetite crystals, which are almost certainly due to ancient bacterial life forms.
The team says that microscopic crystals found in the rock are almost certainly fossilised bacteria that have many characteristics in common with bacteria found on Earth.
“The evidence supporting the possibility of past life on Mars has been slowly building up during the past decade,” said David McKay, Nasa chief scientist for exploration and astrobiology.
“This evidence includes signs of past surface water including remains of rivers, lakes and possibly oceans and signs of current water near or at the surface.”
Studies in 1996 originally suggested this, but the debate was pretty hot at the time — new evidence coming from the most recent round of studies refute critics’ claims that this form of crystal could form due to thermal decomposition.
So, now the question is, did life from Earth get seeded up to Mars, vice versa, or did abiogenesis happen on two planets in our solar system? If the third option, then there goes the egocentrism around which most personal-god theism is based — that some divine creator created life on Earth uniquely and life is some kind of rarity that could never happen by itself (no matter how long it was given or how favorable conditions were to such an event). This won’t stop deists and people who worship nature itself but call it “God”, mind you — but such people are far less of a threat to rationality than those that believe in the supernatural.
This is really exciting news, but I’m not sure if it’s conclusive yet. Some of the researchers back in 1996 were pretty confident that they had found clear evidence of life as well, but most other experts disagreed. I think that we’ll have to wait and see here if the same thing happens or if it really holds up under scrutiny this time.
In any event I hope that this spurs a continuing long-term commitment from many countries to fund new generations of robotic craft for research on both Mars and other planets, moons, asteroids, etc., in the solar system. If the verdict is that it is probably of biological origin, then there is a major incentive to explore Mars a lot more to see if we can find any evidence on the planet itself. Who knows, there might even be funding for crewed missions!
It’s certainly not as conclusive as I’d like. I am hopeful though, with all the new circumstantial evidence that keeps popping up (e.g, the aforementioned water, the methane outgassing, etc.), that we will find some kind of biotic or even prebiotic life there. Of course, even if we very conclusively find ironclad evidence, someone’s bound to say “oh, we seeded it there with our probes obviously”. And some people will say there’s whole civilizations on Mars and that Cydonia was covered up by the government and blah blah blah.
I wonder how biotic life on Mars would affect us. If it would be infectious. Probably would be nothing like Doctor Who’s “Waters of Mars”, mind you, but it would be interesting. As long as it doesn’t turn epidemic.
I’m hopeful, too. If we do find living things, hopefully they will be different enough from anything on earth to rule out contamination from earth in the last few decades as a possibility. It might be quite different even in the most basic aspects of its biochemistry. If the most basic biochemistry is very similar, that would seem to lend weight to the theory that either earth or mars was “seeded” from the other planet early in the history of life.
I’ve read somewhere that organisms from, say, Mars would most likely not be very dangerous or infectious – lots of differences in chemistry and a lack of a any evolutionary “experience” of living inside larger organisms would probably make the inside of our bodies (or the bodies of most other earth organisms) fairly inhospitable to Martian microbes. On the other hand, it would be crazy to just assume that there is no risk – with bad luck, there could be something that thrives inside a human body and has lethal effects simply by coincidence.