Quizzes & Puzzles12 mins ago
Life On Mars?
A group of academics say they have identified fossilised sponges, corals, worm eggs, algae and more on the surface of Mars, and say life there may even be thriving today.
“We have photos of fungi growing out of the ground, increasing in size, increasing in number, as based on sequential images,” said Dr Rudolph Schild of the Harvard-Smithsonian Center for Astrophysics, speaking on behalf of the researchers.
Finding life somewhere other than Earth would have major implications for humanity, proving for the first time that we are not alone in the universe. And if life is present so close to home, it opens fascinating questions as to what life might be like further afield.
“Definitive proof would tell us we are not alone,” added Dr Schild. “We could assume that life has evolved on innumerable Earth-like planets.
“This then raises questions about the antiquity of life. There are planets and Solar Systems that are billions of years older than our own. What if human-like life evolved on those planets billions of years ago? The implications are staggering and humbling.”
https:/
Exciting stuff? I think so. What say you?
“We have photos of fungi growing out of the ground, increasing in size, increasing in number, as based on sequential images,” said Dr Rudolph Schild of the Harvard-Smithsonian Center for Astrophysics, speaking on behalf of the researchers.
Finding life somewhere other than Earth would have major implications for humanity, proving for the first time that we are not alone in the universe. And if life is present so close to home, it opens fascinating questions as to what life might be like further afield.
“Definitive proof would tell us we are not alone,” added Dr Schild. “We could assume that life has evolved on innumerable Earth-like planets.
“This then raises questions about the antiquity of life. There are planets and Solar Systems that are billions of years older than our own. What if human-like life evolved on those planets billions of years ago? The implications are staggering and humbling.”
https:/
Exciting stuff? I think so. What say you?
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The consensus amongst astrobiologists points to water in its liquid form as an essential ingredient to sustain life. There is evidence to support water was once present on Mars. Therefore and understandably some will enthuse at the expectancy of life, if not in the present, but at sometime in the very long distant past.
For me, the chances of life existing in two different places in our very own solar system just seems statistically infeasible!!
For me, the chances of life existing in two different places in our very own solar system just seems statistically infeasible!!
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Indeed, the question of how "statistically (in)feasible" life is on other worlds in our Solar System seems quite open. It surely also depends on what you consider to be "life". The evidence on Earth, I think, shows that life must have arisen very quickly indeed in the Earth's history, and perhaps even at more or less the earliest opportunity. It doesn't seem to be much of a stretch, based on that, to argue that even if there were just the smallest window of opportunity, then life will have taken it on other worlds too.
Of course, once you start seeking *complex* life, that's a whole different question, and conditions for that may be very selective indeed. But it would be enough to find simple forms of life, or their unambiguous traces, to be excited.
Of course, once you start seeking *complex* life, that's a whole different question, and conditions for that may be very selective indeed. But it would be enough to find simple forms of life, or their unambiguous traces, to be excited.
Athiest \Surely we have a sample of one, and that can tell us nothing?\
Your comment taken statistically and in isolation is correct!
ClareT \if there were just the smallest window of opportunity, then life will have taken it on other worlds too\
Consider this though. There are several key cornerstones upon which the existence of life on earth depend. The mass of our sun, earth's distance from the sun so as to maintain enough water in its liquid form, its magnetic core and the atmosphere itself, whose greenhouse effect prevents water from freezing.
IMHO, it is unlikely the above criteria can be met in a different place within our own solar system. I would much prefer time and money was spent on looking elsewhere for habitable conditions with the outlook of human colonisation, than searching for life on Mars.
Your comment taken statistically and in isolation is correct!
ClareT \if there were just the smallest window of opportunity, then life will have taken it on other worlds too\
Consider this though. There are several key cornerstones upon which the existence of life on earth depend. The mass of our sun, earth's distance from the sun so as to maintain enough water in its liquid form, its magnetic core and the atmosphere itself, whose greenhouse effect prevents water from freezing.
IMHO, it is unlikely the above criteria can be met in a different place within our own solar system. I would much prefer time and money was spent on looking elsewhere for habitable conditions with the outlook of human colonisation, than searching for life on Mars.
Quite -- but even if not, then I think kuiperbelt's comment is also too fixated on sustained life, or complex life -- or, at the very least, on life still existing today. It's possible for example that life of some form was present on Venus, say, early in its history, before the current conditions took over. Granted, establishing this one way or another is particularly difficult on Venus, but even still, four billion years is a long time, and you only need habitable conditions on the planet for, say, a few tens of millions of years (which is thought plausible, see eg http://
At the other end, one can arguably exaggerate the role the Sun plays in sustaining life (in terms of distance, light etc) -- it's difficult to see how relevant the Sun is, for example, to sustaining life found at the bottom of the Ocean, where its light doesn't penetrate and so its influence is at most indirectly felt; likewise, the existence of the "deep biosphere", which is to say life that exists well below the surface of the Earth's crust, is also pretty evidently free of the Sun's influence.
All of this means, in effect, that even on Earth the conditions required to maintain life in some form are not actually that tightly constrained. So, not only do you have Naomi's point that maybe there are other conditions beyond our planet in which life could emerge, but you also have solid evidence that it can exploit all sorts of conditions -- from low to high temperatures, from low to high pressures, with little available water or lots of it, with a lot of oxygen or none at all, with abundant energy sources or with the bare minimum, etc etc.
This isn't to say that life can emerge literally everywhere, or can maintain itself indefinitely regardless of the conditions or what changes may occur, but I *do* think it says that one should take seriously the idea that life can emerge on other planets, or other moons, in the Solar system. There is, for example, plenty of water on Enceladus, or Europa, or Titan -- also the only moon in our solar system with a significant atmosphere. There are apparently many other moons of interest, too numerous to mention, and while some of this may be wishful thinking, there's enough interest that several missions have already been funded over just the coming decade to visit a few of these places.
Even if those missions find nothing, or nothing concrete, it seems worth looking.
At the other end, one can arguably exaggerate the role the Sun plays in sustaining life (in terms of distance, light etc) -- it's difficult to see how relevant the Sun is, for example, to sustaining life found at the bottom of the Ocean, where its light doesn't penetrate and so its influence is at most indirectly felt; likewise, the existence of the "deep biosphere", which is to say life that exists well below the surface of the Earth's crust, is also pretty evidently free of the Sun's influence.
All of this means, in effect, that even on Earth the conditions required to maintain life in some form are not actually that tightly constrained. So, not only do you have Naomi's point that maybe there are other conditions beyond our planet in which life could emerge, but you also have solid evidence that it can exploit all sorts of conditions -- from low to high temperatures, from low to high pressures, with little available water or lots of it, with a lot of oxygen or none at all, with abundant energy sources or with the bare minimum, etc etc.
This isn't to say that life can emerge literally everywhere, or can maintain itself indefinitely regardless of the conditions or what changes may occur, but I *do* think it says that one should take seriously the idea that life can emerge on other planets, or other moons, in the Solar system. There is, for example, plenty of water on Enceladus, or Europa, or Titan -- also the only moon in our solar system with a significant atmosphere. There are apparently many other moons of interest, too numerous to mention, and while some of this may be wishful thinking, there's enough interest that several missions have already been funded over just the coming decade to visit a few of these places.
Even if those missions find nothing, or nothing concrete, it seems worth looking.
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