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Evidence of life on Mars - how likely?

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Original post by kalclash
Earth's dinosaurs became extinct roughly 45 million years ago. If someone were looking at Earth from a telescope there would be no visible evidence that dinosaurs ever existed.

Therefore could the same be true of Mars? Could there have been intelligent civilizations that died out many millions of years ago that have been since hidden?

Is it possible that if archaeologists were able to dig beneath the surface we'd find evidence of once great civilizations that have been forgotten by time? Could Mars have supported life many millions of years ago?

Water disappeared from the Martian surface more than a billion years ago. We would have to dig deep under the dust to find fossils - if there is any.

Spoiler




Water still exist on Mars as underground ice, so it might be possible that bacteriae have survived in there, but again, we would have to dig deep to find out.
(edited 7 years ago)
Original post by Kittyboy
Nitrogen can form a dative bond with boron. It can form 4. "Earth like conditions". Again, all of this is based on the earth. Your argument is flawed :P


Nitrogen does not possess the ability to bond to the wide variety of atoms needed to sustain life as we know it. Furthermore it can't form large tetravalent compounds like Carbon can which would be needed for life.

It's true that is all based off the earth but that is because earth has the unique conditions avaliable for the formation of intelligent life.

Furthermore most experts agree than any life on other planets will have formed under conditions similar to life on earth. Water is a unique solvent in that it possess certain properties that make it a particularly stable solvent in which life can form in. Of course, some primitive life can exist with little water environments, but we have yet to find any examples of complex multi-cellular life which can thrive in low water environments or in any alternative solvents known to earth
Original post by Josb
Water disappeared from the Martian surface more than a billion years ago. We would have to dig deep under the dust to find fossils - if there is any.

Spoiler



Water still exist on Mars as underground ice, so it might be possible that bacteriae have survived in there, but again, we would have to dig deep to find out.


There is actually hypersaline liquid water on Mars, definitely in the shallow subsurface and it has been observed ephemerally at the surface.
Ahem.




Wait why are we talking about water now? Isn't that off topic?
Original post by Plagioclase
This is really controversial


??? Doesn't fit in with the rest of what you said


(I alluded to a combination of nitrogen and boron since stability was apparently the key, not just nitrogen or boron in isolation =D
I suppose respectable scientists base their knowledge on just what's happened on earth then lmao)
Original post by Kittyboy
Ahem.




Wait why are we talking about water now? Isn't that off topic?


Haven't you been paying attention to anything I've typed up to this point? Surely you must know by now that complex biochemical processes in cells require a solvent medium in which reactions take place in? This applies to prokaryotic life and eukaryotes alike. It is due to the unique properties of water that life has been able to exist thus far.

Why do you think most astronomers think that the most likely extraterrestrial places to support life in the solar system are also places with water on?
We weren't talking anything about solvents, so I might ask the same to you :P

And then why can't another type of solvent be used aha? "Life as we know it" lmao. Your argument is so heavily flawed
there may be advanced lifeforms on Uranus.
Original post by Kittyboy
We weren't talking anything about solvents, so I might ask the same to you :P


Well you can't have life without solvents, I'm afraid
Read my now edited post, i added to it.

By the by, that's entirely irrelevant. We weren't talking about solvents, I'm afraid
Original post by the bear
there may be advanced lifeforms on Uranus.


Good contribution. You should invite some more of your bear fellows into this thread.
Original post by Kittyboy
Read my now edited post, i added to it.

By the by, that's entirely irrelevant. We weren't talking about solvents, I'm afraid


Because there is no other solvent medium that can support the biochemical processes required for life that fits the bill quite as well as water can. If you think you know better than the scientists of NASA searching the moons of Jupiter for extra terrestrial life then you are free to think that, but you are wrong.

You do realise by 'solvent' I'm not talking about the stuff that people sniff up in dodgy places but about the stuff that is an important ingredient for life, right? :laugh:
Uranus may be the cradle of life...*
Original post by Kittyboy
??? Doesn't fit in with the rest of what you said


(I alluded to a combination of nitrogen and boron since stability was apparently the key, not just nitrogen or boron in isolation =D
I suppose respectable scientists base their knowledge on just what's happened on earth then lmao)


1. That was obviously a typo.
2. They are not basing their knowledge on earth, they are basing their knowledge on chemistry and physics. The laws of physics don't suddenly change when you leave the Earth, you can make statements about the behaviour of elements that are true regardless of whether you're on Earth or anywhere else in the universe. Carbon, indisputably, has the most complex chemistry of any element. Scientists are not idiots, they are not saying this because it's a casual observation we've made on Earth. Secondly, I don't get which part of "the cosmic abundance of Boron is too low for it to be a base element for life" you didn't understand. We know that the abundance of Boron is low across the universe, both from theory and from observation. Again, you are the only person in the world who seems to be seriously arguing for Boron-based life or Boron-Nitrogen based life. The idea of non-carbon based life is nothing more than a scientific curiosity or a though experiment, it isn't something that astrobiologists take particularly seriously.

In fairness, it's a lot more likely that life based on a non-water solvent would arise than life based on a non-carbon element. Water is undoubtedly the best and very possibly the most likely solvent for life to be based on but from my understanding, astrobiologists are taking seriously the idea of ammonia or methane based life.
(edited 7 years ago)
Quite as well? Well, the suitability of the solvent must depend on the composition that the organisms are made up of, no? Water may be good for us carbon based lifeforms on earth, sure. And even if that's wrong, then "quite as well" isn't really stating that other solvents can't be viable. Perhaps water isn't in abundance on other planets, and another type of solvent is.

I thought you were assuming that I had a grasp of GCSE science lmao. Please, along with your "I'm afraid" phrase you're just coming across as impertinent in a patronising kind of way. Is that really necessary? Let's have a friendlier atmosphere yea?
Original post by Plagioclase
1. That was obviously a typo.
2. They are not basing their knowledge on earth, they are basing their knowledge on chemistry and physics. The laws of physics don't suddenly change when you leave the Earth, you can make statements about the behaviour of elements that are true regardless of whether you're on Earth or anywhere else in the universe. Carbon, indisputably, has the most complex chemistry of any element. Scientists are not idiots, they are not saying this because it's a casual observation we've made on Earth. Secondly, I don't get which part of "the cosmic abundance of Boron is too low for it to be a base element for life" you didn't understand. We know that the abundance of Boron is low across the universe, both from theory and from observation. Again, you are the only person in the world who seems to be seriously arguing for Boron-based life or Boron-Nitrogen based life. The idea of non-carbon based life is nothing more than a scientific curiosity or a though experiment, it isn't something that astrobiologists take particularly seriously.

In fairness, it's a lot more likely that life based on a non-water solvent would arise than life based on a non-carbon element. Water is undoubtedly the best and very possibly the most likely solvent for life to be based on but from my understanding, astrobiologists are taking seriously the idea of ammonia or methane based life.


How so? Ammonia has weaker hydrogen bonds than water and is also flammable in oxygen. It's ability to hold together the complex organic compounds required for life is in dispute

Hydrocarbons such as methane do not possess the polarity exhibited by either water or ammonia so is an inferior solvent to both.
Original post by Plagioclase
1. That was obviously a typo.
2. They are not basing their knowledge on earth, they are basing their knowledge on chemistry and physics.

Forget physics for a second, and focus on chemistry as I did. It's remarkably similar to the other dude bringing in solvents all of a sudden. I wish people would stop going off at tangents :/

How can they possibly know that another type of element won't be able to take a similar role to carbon? You talk about carbon's complexity, but is that really such a big deal? Other elements might be a bit less complex, but that doesn't mean that they cannot support life, surely?
Original post by Kittyboy
Quite as well? Well, the suitability of the solvent must depend on the composition that the organisms are made up of, no? Water may be good for us carbon based lifeforms on earth, sure. And even if that's wrong, then "quite as well" isn't really stating that other solvents can't be viable. Perhaps water isn't in abundance on other planets, and another type of solvent is.

I thought you were assuming that I had a grasp of GCSE science lmao. Please, along with your "I'm afraid" phrase you're just coming across as impertinent in a patronising kind of way. Is that really necessary? Let's have a friendlier atmosphere yea?


Please see my post below to Plagioclase.

Even a GCSE student would know that 'solvent' in this context refers to the contents inside a biological cell, not the stuff in a glue tube. It's another way of saying cytoplasm, if you will
They're inferior solvents but metabolic pathways using them as solvents have been predicted. Ammonia being flammable in oxygen is irrelevant if anaerobic metabolic pathways are used (i.e. most metabolic pathways) and obviously methane is even more exotic but it's still being studied seriously by exobiologists, that's the whole reason behind the NASA investigations into life on the Jovian and Saturnian moons, e.g. Titan.
I never said that I thought solvent was the stuff in a glue tube? I think your patronising attitude is grasping for straws lol.

By the sounds of it ammonia seems like a mighty fine solvent :smile:

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