Might Mars Contain Life? 368
stagmeister writes "According to the BBC, the Viking probes to Mars in the 1970s "detected strange signs of activity in the Martian soil - akin to microbes giving off gas," and that while those findings were not acknowledged as proof of life then, "in 1997, reached the conclusion ... that the so-called LR (labelled release) work had detected life." At the same time, the British are launching a probe to try to find life on Mars."
Comfort (Score:5, Interesting)
what to look for? (Score:5, Interesting)
I would have to agree, this is the tough part. The evidence is 20 years old from Viking, and its still being debated. Remember the martian rocks that "contained signs of life"? Me either.
. We're not even sure what to look for ... at least we're pretty damn sure what water looks like at this point ... these missions are expensive, I wouldn't waste a mission on something unlikely to succeed anyway.
Fascinating, Mr Spock (Score:5, Interesting)
For example, is the life DNA based? All life on earth is DNA based, and if the life elsewhere isn't then we are going to learn a lot by studying it - it will be an using an entirely different mechanism to do essentially the same thing as DNA. How does it work? How did it evolve?
And if it *IS* DNA based then we need to find out if DNA is the logical conclusion of evolutionary biology... ie, I can imagine that intelligent life elsewhere have designed the same things we have (think "the wheel") because there are only so many ways you can do something. Therefore, is DNA (or something very similar) the only mechanism life can use to sustain itself? Or did the DNA originate from the same place as DNA on the earth? And if so, how?
contamination (Score:5, Interesting)
What are the chances those probes contaminated Mars with terrestrian microorganisms? Since the 1970's it was discovered life is more resilient than it was thought, with bacteria not only surviving, but thiriving, in mediums considered to be sterile - like in thermal water springs or nuclear reactor cores.
The meaning of "sterile" has changed a lot - see what measures NASA is preparing to take now for a (still theoretical) mission to Europa (Jupiter's satellite, for the challenged).
Life on Mars? (Score:1, Interesting)
And is there intelligent life on Slashdot?
Ok, three things, is there life after Slashdot?
Re:Carl Sagan said no (Score:3, Interesting)
A Closer Look at the Summer of '76 (Score:4, Interesting)
I remember the summer of 1976 well.
Not because our big cartoon-broadcasting neighbor to the south had just turned 200 years old. Not because the Olympics were in Canada, nor because Nadia Comaneci scored the first perfect 10 in Olympic history - causing one of the most famous computer crashes in history. Not even because Disco Duck was Top 40.
I remember the summer of 1976 vividly because Viking 1 touched down on the flat plains of Chryse Planitia on Mars, and shortly thereafter discovered the first scientific evidence of extraterrestrial life - a very big event for a nine year old spacegeek like me. Curiously though, not long after NASA announced discovering life on Mars, they retracted their statement and said what they detected was not life, but rather an unusual chemical reaction.
Re:Fascinating, Mr Spock (Score:2, Interesting)
Peroxides != life (Score:5, Interesting)
They found nothing more than solid peroxides (which tend to evolve oxygen when exposed to water), along with some unusual (but entirely explicable) iron-catalyzed reactions (remember why we call it the "red" planet).
Now, that doesn't disprove the presence of life, particularly a few meters below the surface. It does, however, present a VERY hostile surface environment (even ignoring the temperature and lack of an active planetary magnetic field) to life as we know it on Earth.
Hey, I'd like to find life there as much as the next guy... But it takes quite a leap of faith to interpret the Vikings' readings as "life". And science does not (or at least, should not) include any aspect of "faith".
Re:Fascinating, Mr Spock (Score:5, Interesting)
For example, is the life DNA based? All life on earth is DNA based, and if the life elsewhere isn't then we are going to learn a lot by studying it - it will be an using an entirely different mechanism to do essentially the same thing as DNA. How does it work? How did it evolve?
There is evidence for at least _some_ cross-contamination between Earth and Mars occurring. If we find DNA or RNA based organisms there it may just be that they were seeded from here (or vice versa, back when Mars had water and a thicker atmosphere).
The place to look for *really* interesting things is environments that are isolated from ours, or that have conditions different enough that a different basic chemistry would be required.
Thermal vents on Io would be one option - there's lots of interesting sulphur-based chemistry upon which complex organisms could be based.
The oceans of Europa would also be an interesting spot - it's far from earth, and the potentially (earth-like-) life-bearing areas are beneath a thick crust of ice, so cross-contamination is less likely.
Cold worlds like tidally-heated moons of the outer gas giants would also be an interesting place to look. At those temperatures, life would a) run much more slowly and b) have to be based on lower-energy processes and substances with weaker binding forces for the available energy to be used to break down and rebuild biochemicals.
When we finally have probes capable of doing really detailed chemical and biological surveys of the outer solar system, we're going to find some very interesting things. Our own world shows us that microbes, at least, will show up wherever there's the energy and chemistry to support them.
Re:Carl Sagan said no (Score:5, Interesting)
Can't recall off the top of my head if it was the preasure/temp or both that changed.. but the environment in the experiment was not that of mars surface which caused the problem.
Why not seed life? (Score:3, Interesting)
Re:Comfort (Score:3, Interesting)
This is based on what? The planets we've detected thus far? Well, since we can only detect extrasolar planets that are as or more massive than Jupiter it's no wonder that they're all looking awfully big! I bet if you go to a Ford plant and look at what cars they make you'll only find Fords too. Doesn't mean that there are only Fords out there though.
We have no way of knowing that our solar system is typical (nor do we know that it's atypical), but if we were to use it as a basis point then you could say that 5/9's or more of the planets in the universe will be non-gas giants. Because of the 9 commonly recognized planets (no, don't go there) only 4 are gas giants. But that's about as much of a fair comparison as your statement is... the reality is we won't be able to make good guesses about extrasolar planetary systems until we have much, much better telescopes and other detection mechanisms.
Sure, we have models, and those models seem to indicate that our solar system is rare, but none of the models is completely accurate. And they're all based off of a single data point.
Life on Mars may not increase the likelihood of life being elsewhere in the Universe -- since life on both planets could have come from the same source (which is not necessarily Earth). But it does mean that life can exist on other planets, and that's a big step. A huge one.
This whole life on Mars things is a red herring (Score:2, Interesting)
Exploration is not about finding answers to pre-formulated questions. It is much more open ended than than, its about expanding horizons and finding new unexpected opportunities.
Another problem with the life-as-a-reason to explore mentality is that at some point the jig is gonna be up: there is very little chance of finding life on Mars and once the answer is concluded positively no, will the people turn away from space exploration?
Re:No doubt (Score:1, Interesting)
Guess our government would rather see stealth bombers murdering people than a manned space flight to mars. Make space shuttles not war....
Dont forget that much of our space technology came from things learned while planning/preparing/inventing for war.. as well as the other way around
The most interesting question to me is... (Score:3, Interesting)
I can not wait to hear the spin put on that one.
Note: I am serious when I say it is the most interesting question. I really do want to hear how the world's religons grapple with this issue if/when it does arise.
Re:Peroxides != life (Score:3, Interesting)
Have you tested EVERY theory that your hypothesis relies on in preparation of your current experiment?
No?
Are you *SURE* gravity on earth is 9.8m/s^2? When was the last time you tested it? And are you sure of that meter?
Science is just chock full of "faith"... read any experiment which begins "Given X..." You have to trust that you know what X is and that it is true.
robotic sample return mission (Score:2, Interesting)
With sample return mission, we can also afford to do things like look for DNA, RNA, and proteins. That would be impractical and too high risk to do with just a robotic lander, but it would be cheap and easy to perform those tests on returned samples.
We've known this for thirty years (Score:4, Interesting)
(For those who remember the Cosmos series by Carl Sagan, there is a section on this where he mentions the experiment designed by his friend Wolf Vishniac, which IIRC was not one that was included on the Mars jaunts, but did discover life in Antarctic valleys previously thought sterile.)
There were three experiments. It was agreed that the likelyhood of life was so low that a positive in any one would be treated as evidence of living processes. Two were positive, the other was negative. Despite the undertakings before the mission, the single negative was treated as the official and definitive answer to the question "is there life on Mars". The other two were explained away as 'merely chemical processes'. (Of course, so are things like respiration and digestion.)
Given the current state of evidence, the best we can say as to life on Mars is 'maybe', and we need more experiments -- experiments where the rules aren't changed halfway through because the data is unexpected would be nice!
Re:Comfort (Score:3, Interesting)
Religion is a memetic virus. It mutates, adapts, and evolves for the sole purpose for propagating itself.
Language is a virus, too.
Re:Comfort (Score:5, Interesting)
Anyway, science and religion don't have to be at odds. In fact, they shouldn't be at odds -- religion and technology may often have a beef with each other, but science should just be seen as exploring God's creation.