I don't think anyone ever doubted that water once ran on Mars. Now. Was there microbial or plant life there once ??

I don't think anyone ever doubted that water once ran on Mars. Now. Was there microbial or plant life there once ??

I don't see why not, Will'. Even if oxygen was absent in the atmosphere
then there must be every chance that some plant life's were able to extract
it from the water....that's even if they actually needed it?
Yet we might find evidence that Mars once had an atmosphere very similar to
that of Earth but simply lost it over time. I wonder if it's low gravitational
field has any thing to do with this loss.

For sure though, since we have another planet in our solar system that shows
signs of having had the potential for life on it even if only rudimentary plant
life then how many of these type planets then exist out in the universe?
I've been a believer in that only Earth has life on it but I'm now undergoing
a radical rethink on it all since the Mars data has started coming through.
Should breath new life into Seti although I feel that Earth posses the only
form of intelligent life. Yet only a fool would follow this philosophy blindly
hence rather than be a fool I assist in the search for intelligent life via Seti.

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The Kite Fliers

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Kite fliers: An imaginary club of solo members, those who don't yet
belong to a formal team so "fly their own kites" - as the saying goes.

I don't think anyone ever doubted that water once ran on Mars. Now. Was there microbial or plant life there once ??

The important bit is that the gravels show signs of long term erosion suggesting that there was flowing water for a long time.

All past suggestions for water on Mars have always been tempered by the assumption that the surface water could never last for long due to the atmosphere for Mars always being rapidly ripped away and depleted by the solar wind.

Perhaps liquid water could have been there long enough for life to start?...


Keep searchin',
Martin

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Take a look for yourself: Linux Format
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I don't think anyone ever doubted that water once ran on Mars. Now. Was there microbial or plant life there once ??

The important bit is that the gravels show signs of long term erosion suggesting that there was flowing water for a long time.

All past suggestions for water on Mars have always been tempered by the assumption that the surface water could never last for long due to the atmosphere for Mars always being rapidly ripped away and depleted by the solar wind.

Perhaps liquid water could have been there long enough for life to start?...


Keep searchin',
Martin

Good point Martin!

People should be very careful in assuming that liquid water can exist on the surface of Mars. Because liquid water CAN'T exist on the surface of Mars without some kind of container to hold it together.

Fact No.1 - If there is no gravitational pull to hold water molecules together, or a container of some sort, they will evaporate away into empty space. So if you were on the international space station, and you emptied a bucket of liquid water out the window, it would evaporate away into space. It would NOT stay liquid!

Fact No.2 - If you were standing on the surface of Mars today in your space suit, and you opened a bottle of liquid water, the water would evaporate away because there isn't enough gravity on the surface of Mars to keep the water liquid.

And to be honest, its even questionable if there was ever conditions on Mars, at any stage in the planets history, for liquid water to exist!

Maybe its possible that some other type of liquid (not water) could have flowed on the surface of Mars at some stage.

I personally don't believe that "liquid water" could ever have existed on the surface of Mars. I don't care what NASA says.

John.

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Aside from the Pheonix lander having actually found water, whats not to believe. Remember faith takes belief. Science takes evidence. The probes have already found evidence.

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In a rich man's house there is no place to spit but his face.
Diogenes Of Sinope

I was speaking of the Phoenix lander. It showed photos of uncovered frost and its evaporation. That pretty strong evidence

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In a rich man's house there is no place to spit but his face.
Diogenes Of Sinope

I personally don't believe that "liquid water" could ever have existed on the surface of Mars. I don't care what NASA says.

Johnney .......

Chris,
I take it your looking for me to back up my statement with some quality science.

Ok;
The gravitational pull on the surface of Mars is 0.376 g[http://en.wikipedia.org/wiki/Mars], or roughly one third the pull of gravity on the surface of earth. In Earths gravity, water can exist as a liquid on the surface because of the surface temperature, roughly 20 degrees C, which is a direct result of the Earth's gravitational pull. But on Mars, the planet was never any bigger in its past, so its highly unlikely that its surface gravity was every any different. And Mars is too far from the Sun to heat up the water. Hence liquid water could never have existed on its surface. The surface temperature and "pressure" was never high enough to allow water to exist as a liquid.

John.

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It's entirely possible that Mars' atmosphere was at one time substantially thicker than at present. It is believed that the solar wind gradually eroded this atmosphere; Mars' relatively low gravity being unable to to retain it against such an onslaught. A thicker atmosphere could have allowed liquid water to be much more stable on the surface. It could also have allowed higher temperatures, which would permit liquid water, instead of just ice. The signs of land erosion by what appear to have been rivers points strongly to such an environment. What other liquid is proposed that could have eroded channels, deltas, and the like, and left mineral deposits characteristic of those left behind by water?

It's entirely possible that Mars' atmosphere was at one time substantially thicker than at present. It is believed that the solar wind gradually eroded this atmosphere; Mars' relatively low gravity being unable to to retain it against such an onslaught. A thicker atmosphere could have allowed liquid water to be much more stable on the surface. It could also have allowed higher temperatures, which would permit liquid water, instead of just ice. The signs of land erosion by what appear to have been rivers points strongly to such an environment. What other liquid is proposed that could have eroded channels, deltas, and the like, and left mineral deposits characteristic of those left behind by water?

Michael,
Its the Earth's gravity is the reason we have roughly 100km of atmosphere(Air) over our heads. Remember the Moon is one sixth the Mass of Earth and can't hold any atmosphere at all. Mars is a much smaller planet, and has only one third our gravity. This is why Mars has only a very very thin atmosphere. Its because it doesn't have enough gravitational pull to pull the air molecules down to the surface. And unless Aliens had a massive gravity generator in the middle of Mars in its past, then it never had a stronger gravity, and hence it never had enough "pull" to hold a thicker atmosphere.

So if "liquid" flowed on Mars at some stage, it wasn't water. But its possible that some other substance did flow. Keep in mind that with the thin atmosphere on Mars, it gets hugh winds. This could move hugh amounts of sand across the surface that will erode channels and it might look like a liquid flowed there in the past. There is frozen water on the poles of Mars.

John.

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NASA JPL News - Curiosity takes a scoop of Mars dirt!

Curiosity Report (Oct. 4, 2012): Rover Gets Set to Scoop
http://www.youtube.com/watch?v=I5b6KSTst-o (2 minute news video)

John.

Using a laser and X-rays, the NASA rover Curiosity identified a rock named Jake as a form of basalt, similar to volcanic rocks found in ocean-island settings on Earth.


The rock named Jake Matijevic that Curiosity explored for several days on Mars. Red dots indicate areas where the rover shot the rock with laser blasts while purple circles indicate areas investigated with X-rays beams. NASA/JPL-Caltech/MSSS


Curiosity Rover Finds Rock Type That’s Never Been Seen on Mars

Lynn,
Ok, thats clear evidence that Martians were drawing purple lines and red dots on the rocks on Mars. The evidence is undeniable!!!

Yipeeeee....We got em!! This is the big one!! We have evidence of Martians doing children's drawings on the rocks!! We have proof of aliens on Mars!!

John :)

Lynn,
Ok, thats clear evidence that Martians were drawing purple lines and red dots on the rocks on Mars. The evidence is undeniable!!!

Yipeeeee....We got em!! This is the big one!! We have evidence of Martians doing children's drawings on the rocks!! We have proof of aliens on Mars!!

John :)

Alrighty then , agreed :-)

But, scientists expected to find a rock similar to the ones seen on previous missions to Mars. But instead, they found a rock with a composition seen in many rocks on Earth.

But, scientists expected to find a rock similar to the ones seen on previous missions to Mars. But instead, they found a rock with a composition seen in many rocks on Earth.

Lynn,
the conclusion i draw from that is that Earth and Mars have similar rocks, which is not really surprising at all.

John.

I am actually heartened by this discovery as together with apparent evidence that water did once fow on mars, then their s more liklihood that forms of life as we know them may have existed.

Chris,
They didn't! There was never life on Mars, ever ever ever. Chris life as we know it is made from cells with DNA. Mars NEVER had an atmosphere that was thick enough to protect living things. The surface of Mars is lethal to the cells that make up living creatures. The radiation from the Sun that hits the surface of Mars will destroy all living things. And the gravity of Mars is not strong enough to have ever allowed liquid water to flow anywhere.

John.

Curiosity has shown what is very similar to a river bed, with pebbles rounded by streaming water. This is what NASA scientists say.
Tullio

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Curiosity has shown what is very similar to a river bed, with pebbles rounded by streaming water. This is what NASA scientists say.
Tullio

Yes Tullio,
I was swallowing that story myself for the last number of years. It does sound very plausible that liquid water might have flowed there in the past. And yes, the pictures from Mars clearly show what they call "Gullies". And they look just like water erosion here on Earth. So at first glance, it seems to make sense.

But!! The fact remains, Mars was never any bigger, so it never had a stronger gravity. Its gravity that is "pulling" our atmosphere to the surface. Its Earths gravity that gives water the property of flowing like a liquid on the surface of Earth.

But Mars is different, less gravity, its much colder because it further from the Sun. Therefore frozen water won't transition from the solid phase to the liquid, to the gas phase the same way as here on Earth. As soon as frozen water is heated on Mars by the Sun, it goes straight from solid to gas and evaporates off.

Look i'm not entirely sure that my science is exactly correct. Maybe i'm right, maybe i'm wrong. I keep an open mind.

John.

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I know that a radar on the Mars Reconnaissance Orbiter, incidentally made in Italy, has found deposits of water ice under a gravel cover even at middle latitudes. So Mars once had water. It must have mostly evaporated, as you say, but maybe for a short period of time it was in liquid form.
Tullio

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I know that a radar on the Mars Reconnaissance Orbiter, incidentally made in Italy, has found deposits of water ice under a gravel cover even at middle latitudes. So Mars once had water. It must have mostly evaporated, as you say, but maybe for a short period of time it was in liquid form.
Tullio

Yes, maybe its possible Tullio.

But this Rosie concept people have in their head of oceans of liquid water once flowing across Mars is wrong. Its just not that simple.

As i say, i keep an open mind.
John.

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Curiosity is a long range mission, thanks to its nuclear power. Did you see it has no solar panels?
Tullio

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