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If the Curiosity rover had been sent to Mars in ancient times, it might have found itself sinking in a stream. The 2,000-pound super-rover, which made its now-legendary landing on Mars on August 6, has come across stones in conglomerate rock suggesting that water must have flowed there in the past. One such rock outcrop is called Hottah, after Hottah Lake in Canada's Northwest Territories. It looks like someone took a jackhammer and lifted up a sidewalk, said John Grotzinger, lead scientist for the Curiosity mission, at a press conference Thursday. The consensus is that "this is a rock that was formed in the presence of water," Grotzinger said. "We can characterize that water as being a vigorous flow." In and around this bedrock, Curiosity has come across rounded gravels. The rocks appear to have been subjected to a sediment transport process, carried by either water or wind, said scientist Rebecca Williams of the Planetary Science Institute in Tucson, Arizona.
We have known for decades that Mars once had liquid water on the surface. We have seen evidence of that in lots of places. Furthermore, the Phoenix Mars Lander used a Thermal and Evolved-Gas Analyzer to directly "touch" and "taste" Martian water in August 2008.
At least they had the good sense to not say it was the "first evidence" of water on Mars, like another NASA video I saw.
However, this discovery can claim at least now we have evidence that liquid water must have flowed on the surface of Mars for quite some time. After all, rounded pebbles in streams are not created overnight. Which means that it might be a good location to search for fossilized microbial life.
We also already know there is still water on Mars, in a solid state underground. There certainly could not be any liquid water on, or near, the surface due to the extremely low atmospheric pressure on Mars. What we do not know yet is how accessible that ice-water may be.
I'm curious about what's underneath the surface of Mars. Does anyone think that there are caves.....tunnels, or something made by intelligent life?
-If life existed there, say a million years ago, or 500 million, it seems like there could have been activity underground as the surface changed. Even if its only one cave, or a small area, it could still be extremely significant.
What about plants? Did they ever exist on mars?
-Honestly, I think we seem scared of admiting that life has existed elsewhere. We seem to be tiptoeing around this Mars, water story. How many decades have we known about this? We seem to be drawing out this search for microbial life, when more sophisticated life could very well be possible.
I'm curious about what's underneath the surface of Mars. Does anyone think that there are caves.....tunnels, or something made by intelligent life?
-If life existed there, say a million years ago, or 500 million, it seems like there could have been activity underground as the surface changed. Even if its only one cave, or a small area, it could still be extremely significant.
What about plants? Did they ever exist on mars?
-Honestly, I think we seem scared of admiting that life has existed elsewhere. We seem to be tiptoeing around this Mars, water story. How many decades have we known about this? We seem to be drawing out this search for microbial life, when more sophisticated life could very well be possible.
I am reasonable certain that there are natural caves somewhere on Mars, but nothing created by intelligent life. If life formed on Mars it would have been microbial at best. Similar to what appeared on Earth 540+ million years ago, Precambrian. There also would not have been any plants, beyond primitive algae.
I think it is very likely that life has existed, or could still exist elsewhere besides Earth, just not likely to be complex life forms. Particularly on Mars. The lack of a strong magnetic field, like Earth, and the low gravity of Mars means that its atmosphere would have been stripped off fairly quickly by the solar winds giving it a very low atmospheric pressure (87 times less than on Earth).
The primary reason they are searching for water sources is because that is the most likely place where they will find microbial life. Europa or Ganymede may harbor more complex life forms.
I am fascinated by Mars exporation. I don't think we should discount the fact that diverse lifeforms may have existed at one time on Mars. After all, we are just learning about the Planet.
I am fascinated by Mars exporation. I don't think we should discount the fact that diverse lifeforms may have existed at one time on Mars. After all, we are just learning about the Planet.
True, we are learning about the planet, but we know enough now to be able to draw some rudimentary conclusions. For example, there is no tectonic activity on Mars to recycle its mantle. Which means there was no "iron catastrophe" like there was on Earth 4.15 billion years ago. While the nickel and iron in its molten state sank to become part of Earth's core, that never happened on Mars. Which is why the surface appears red from all the oxidized iron still on the surface of Mars. As a result, Mars only produces a very weak magnetic field, when compared to Earth's magnetic field. It also means that the core of Mars is cooling off at a much more rapid rate than Earth.
Combine this weak magnetic field with Mar's low gravity (0.3875 times that of Earth) and it proves to be insufficient to prevent the solar winds from stripping off most of the Martian atmosphere. The Martian atmospheric pressure is 87 times less than that of Earth at sea level. Which means that anything in a liquid state on or near the surface of Mars would have evaporated straight into a gaseous state. That includes not only water, but also blood and plasma.
What we do not know, yet, is how long that process took. Could it have taken long enough for life to begin to form and take root? Considering Mars formed at the same time that the rest of our solar system forms, 4.65 billion years ago, and complex life only first appeared on Earth within the last 540 million years, it seems highly unlikely that there would be any complex life on Mars. However, since microbial life on Earth first appeared approximately 3 billion years ago, it may be possible to find evidence of microbial life on Mars. That would tell us a great deal, not only about the abundance and likelihood of life on other worlds, but also more about the history and geology of Mars.
It may also be possible to find microbial life on Mars that is older than what we have found on Earth. Being smaller than Earth, it would have cooled off quicker, and as previously mentioned, there is no tectonic activity on Mars to recycle its mantle. Therefore, it should be relatively easy to find some very ancient rocks.
Another important aspect to life on Earth was the moon. Three billion years ago our moon was extremely close to the Earth, causing massive tides more than a thousand times greater than today. It is thought that microbial life first formed on Earth in a tidal pool. Mars has two moons, but they are insufficient to generate any significant tidal forces on the surface of Mars.
I am reasonable certain that there are natural caves somewhere on Mars, but nothing created by intelligent life. If life formed on Mars it would have been microbial at best. Similar to what appeared on Earth 540+ million years ago, Precambrian. There also would not have been any plants, beyond primitive algae.
I think it is very likely that life has existed, or could still exist elsewhere besides Earth, just not likely to be complex life forms. Particularly on Mars. The lack of a strong magnetic field, like Earth, and the low gravity of Mars means that its atmosphere would have been stripped off fairly quickly by the solar winds giving it a very low atmospheric pressure (87 times less than on Earth).
The primary reason they are searching for water sources is because that is the most likely place where they will find microbial life. Europa or Ganymede may harbor more complex life forms.
I'm not an expert in astronomy or the planets, but I think we've barely scratched the surface of our own solar system. We may know 5% of just mercury, venus, and mars. Let alone some of the outer planets. Aren't there lakes of hydrocarbons on titan? That's pretty amazing.
-Speculative, but what if an asteroid, or meteor hit Mars with some type of microbial life on it. What ever happened to that mars meteroite, I think they found it in antarctica? And thought it contained fossils of small bacteria.
What type of complex life do you think may be on europa or ganymede? I wonder if we'll ever get curiosity type probes and vehicles to the moons of jupiter or saturn. Imagine high quality color photos of the surface of those moons, like mars.
I'm not an expert in astronomy or the planets, but I think we've barely scratched the surface of our own solar system. We may know 5% of just mercury, venus, and mars. Let alone some of the outer planets. Aren't there lakes of hydrocarbons on titan? That's pretty amazing.
I think we have more than scratched the surface, but I agree with your basic premise - our knowledge of our own solar system is in its infancy. Yes, there are indeed lakes of hydrocarbons, possibly methane or ethane, on Titan. Unfortunately, that does not bode well for the possibility of life. Liquid hydrocarbons do not make as good of a solvent as liquid water. But then again, life may be more abundant than we realize, so I would not rule out the possibility of life on Titan just yet. When we land a probe and "touch" and "taste" Titan we will know more.
Quote:
Originally Posted by John23
-Speculative, but what if an asteroid, or meteor hit Mars with some type of microbial life on it. What ever happened to that mars meteroite, I think they found it in antarctica? And thought it contained fossils of small bacteria.
It is a fairly common belief that life on Earth, and possibly elsewhere, originated from space. Furthermore, collision tests have been conducted using a single amino acid that produced intact protein ions. In other words, it was the collision itself that may have first sparked life on Earth, and possibly elsewhere.
There does not seem to be a consensus with regard to the Martian meteorite they found in Antarctica. Many are of the opinion that it is evidence of bacterial life on Mars, just as many appear convinced that it is the result of natural mineral formation. I think the jury is still out on that one.
Quote:
Originally Posted by John23
What type of complex life do you think may be on europa or ganymede? I wonder if we'll ever get curiosity type probes and vehicles to the moons of jupiter or saturn. Imagine high quality color photos of the surface of those moons, like mars.
I think it may be possible that Cambrian types of complex life forms may exist within the oceans of Ganymede and Europa. Critters similar to sponges, jelly fish, microbial mats, coral, urchins, and possibility even something resembling trilobites.
I have no doubt that we will have probes far more sophisticated than the MSL on Ganymede and Europa one day. Not in my life time, but certainly within the next hundred years. Until that day all we can do is look and wonder.
Europa
Ganymede
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