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Water on Mars - Clues to Life?
PHPee writes: "Reports of water on Mars say that huge amounts of water gushed through the surface of the red planet fairly 'recently'. (Recently being as little as 10 million years ago)
This is big news, because it may lead to finding some simple forms of life on the planet.
For more info, check out:
(story #1)
and
(story #2)."
Indeed this is great, but I wouldn't qualify it as *news*. I thought it was relatively well established that there was proof of water on Mars. Nothing new has happened since then, but hopefully we will go up and take samples sometime.
Europa, one of Jupiter's moons, is also thought to be one of the prime candidates for life in our solar system.
It is to estimate the likelyhood of more life in the universe,
It is a misconception that water is a requirement for life. Sure, life without water is practically impossible on earth. This is mainly because the melting point and boiling point of water are in the range of temeratures encountered here. That is also where carbon-based lifeforms are usefull.
Now on a much hotter planet for instance, COH lifeforms won't hack it, as the COH bindings are too weak to hold on at very high temperatures. In such cases it would be wise to adapt a Si-based form, which has quite similar characteristics to C when placed at a higher temperature.
On the other hand, when a planet is much cooler, water is pretty useless as it's only present as ice. Mind you: ice is no good when you are dealing with cell-like organisms (as we are). In such case another liquid is more practical (maybe some very apolar fluid)
We shouldn't decide whether something can be called 'life' just because it looks like us. Life should be quantified in terms of energy and entropy instead
If an experiment works, something has gone wrong.
That we may find a form of life which simply cannot be classified by anything we have ever seen on earth. What do we do if this happens?
People expect to go on other planets and find the same lifeforms you see on earth, bacteria, and mammals, and so on, what if you find a lifeform thats unlike anything, like a gas or liquid based lifeform, or something just totally weird.
Scientists should at least be ready for it.
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We should have some major precautions in case we do find a bacterium or some other such life form when we do begin exploring mars more thoroughly. We can't have something that could destroy mankind taking root here or being used for ill purposes. IIRC, there was something about a location being set up for extraterrestrial life in a previous slashdot posting. Hopefully this spot is set up to be highly secure.
On another note, it definitely will be strong evidence for life being universal if we find living organisms on any other body outside of earth. It allows us to determine that there are other orbit zones and climates outside of our own to support life. That would increase the number of planets outside of our solar system that we would believe could support life and thus bolster the theory that we are not alone.
... to determine the practicality of creating human colonies on other planets. If water and life are common, then the entire idea becomes far more practical.
If life already exists on other planets, we should leave them alone. Humankind has enough of a bad track-record of screwing up one planet – sending countless species into extinction and precipitating environmental melt-down.
Only if a planet is proven to be free from life should we consider colonising it.
Rubbish
Neither claim is scientific, the only correct statement now is "Until now we have not found life on Mars", and that will remain the claim until one of two things happen:
- We discover alien life on Mars
- We start living there
In both cases, the claim "there is life on Mars" will be scientifically correct.
Remember, the existence of life on Mars is not and never will be a hypothesis/theory (which is where Popper comes in), it is either a fact or an unknown.
Scientists actually finding that unlikely piece of Mars on Earth, in dirt.
I believe the meteorite you're talking about was found in Antarctica. I have a friend who was doing research there one season, and she said one of the things they would do when they were bored was look for meteorites. Pretty much anything that wasn't snow was a meteorite!
Maybe you should re-evaluate your decision to blindly dismiss the value of scientific exploration. I'm not a geneticist, or a biologist, or any brand of scientist that can speak intelligently about the merits of space exploration or the study of life on earth or abroad. However, i am a scientist, and i recognize that scientific discoveries - many if not most of them - come from the most unexpected places.
I think space exploration and the quest for extra-terrestrial life is an invaluable quest for all the reasons we *don't* know about. You can't tell me (and even if you did i'd tell you that you're full of crap) that if someone finds even one tiny living single-cell organism on mars, that there is no possibility that the study of that one small organism could not be a catalyst of evolutionary discovery for all life as we know it. I'm not saying it will change the world. I'm saying it has the chance of adding to our understanding of the world and of ourselves. Every little bit of knowledge advances us one step closer to scientific goals we may not even know exist yet.
Space exploration and space research absurd? Humans have only been flying for about a century. How many discoveries in how many different fields have come from flight, and space research? Rocketry, physics, medical disoveries on so many levels, engineering and computing advances, biologic and genetic research in space or even modified gravity environments; I'm not sure anyone knows exactly how space research has impacted humanity in the last 50 years, because its influence is just too wide-spread. If someone somewhere develops a cure for some disease, or a bitchin new technology that will drive our cars, or even replace our cars 10, 50, or 100 years from now, i'm all for it. Space research is far from absurd. It's integrally linked to the standard of living you and I enjoy today, and will enjoy tomorrow.
As for protection, buddy, the only thing we need protection from is ourselves at this point. If we can't get to another developed species capable of space travel (assuming as i do that one exists "somewhere"), then we're probably ill equipped to defend ourselves if they can get to us - again, assuming they have nothing but hostile intentions. I chuckle at your expense, and at the same time sigh that close-minded individuals like yourself are all too common.
One of the key characteristics of life as we know it is chirality [chiral.com], which is...(snip)
I don't understand this at all..
First of all, it's very hard for a molecule beyond a certain size to not be chiral - if you have an atom coordinated to 4 different groups, that's all you need.
And although organisms are full of chiral molecules, that doesn't mean that chirality is somehow a "key characteristic of life" - it's just a trivial consequence of the fact that you need big, complicated molecules to build robustly self-reproducing objects.
Carbon-based organic molecules have this property but phosphorus-nitrogen ones do not.
But the polyphosphazene polymers you provide a link to could easily be chiral, if the R groups are different!
Chirality suggests that organic molecules might need to embody certain mathematical characteristics that are fundamental to life. What we would need, therefore, is a mathematical definition of life.
But why do we need a mathematical definition of life, or indeed any definition of life at all? It's not as if, should we find something on Mars that reproduced and grew, and had a sophisticated metabolism to extract energy, but didn't fit some dimly imagined 'mathematical definition', we would shrug our shoulders and say, "Well, that's quaint, but it isn't life, you know.. let's ignore it.". The word "life" is like the word "game" - it's a word we have no problem using in daily life, but coming up with a precise definition is both pointless and impossible.
The thing in the box has no place in the language-game at all; not even as a something; for the box might even be empty.