Can liquid water exist on the surface of Mars?

Question

I always assumed liquid water can exist on Mars. Summer temperatures at the equator on Mars sometimes reach 70 degrees F. So I thought maybe some robot might find a puddle or some mud someday. However, in reading about Mars, I get the impression that liquid water might require some minimum amount of air pressure to keep from evaporating or something. So is the Mars atmosphere too thin for liquid water on the surface? Any help understanding this subject is most welcome.

Answer 1

there has been no discovery of liquefied H 2 O on the surface of Mars.

between 2 orbiters,2 rovers,and one active probe, scientist speculate

that there might be liquid or frozen H 2 O below the surface.

the frozen polar caps are predominantly C O 2.

Answer 2

I don't understand a lot about Mars but I believe the Mars atmosphere is way to thin to allow liquid water to accumulate on Mars' surface.

Answer 3

Yes, the atmosphere is too thin.  It can exist for short periods of time, until it boils away.  The boiling point of a liquid gets cooler as the air pressure goes down, and on Mars the boiling point is about 10 degrees C.  If you have a large quantity of water, like a lake, only the surface begins to boil away, so it decreases gradually.  They think that springs might force streams of water up for short times that can flow for a bit.

Lots of good info here - http://science.msfc.nasa.gov/headlines/y...

Scroll down to the 'triple point phase diagram' picture to see the extremely limited conditions in which liquid water could be found on Mars.

Answer 4

Not for long. Even if it were 70 degrees F it would quickly boil away because the boiling point of water gets less as air pressure gets less. You know water boils at 212F only at sea level. In the mountains it boils at a lower temperature and you have to adjust your cooking, have to boil eggs longer to make hard boiled eggs for example, as a result. On Mars, the air pressure is much lower than on any Earth mountain. Water would boil even if it were colder than 32F. So the result is ice "sublimates" Sublimation is where water changed from a solid (ice) directly to a gas (water vapor) without ever passing through the liquid phase. Now if you had some liquid water in a pressurized container at 70F, and you opened the container, the water would instantly start boiling. And as it boils it is cooling, because it takes energy to change liquid water to water vapor and the energy is carried away by the molecules of the steam. Eventually the remaining water cools to 32F and freezes. I have seen a demonstration of this in a physics class. We put a dish of room temperature water in a vacuum chamber and started the vacuum pump. As the pressure got lower the water started bubbling. Then it suddenly just froze solid. If the vacuum pump kept operating long enough the ice would all vanish as it sublimated into water vapor and got pumped out of the vacuum chamber by the pump. That is what freeze drying is, vacuuming out all the water without using heat. Mars is a freeze dried planet.

Answer 5

Yeah, it's due to pressure. Have you ever gone to a really high altitude area and tried to boil water? It boils at much lower temperatures, around 80 degrees Celsius. Well, at the pressures you'd get on the surface of Mars (less than 1% that of Earth's at sea level), it'd boil immediately above the melting point, essentially sublimating straight from solid to gas.

It can get reasonably warm at the equator in the summer at midday (although I'm not sure about 70 F!), but even with temperatures that support liquid water, you still don't have the right pressure. It's possible there might be some underground. There was certainly liquid water in the past, though - just look at the channels you get on the surface! That'd indicate both higher temperatures and higher pressure, and hence a thicker atmosphere.

Water on Mars is what the Phoenix mission is looking for right now, actually! They've found a bunch of water ice at the North Pole - a lot of it is frozen carbon dioxide, yes, but there are appreciable amounts of water ice as well.

Answer 6

After we terraform it!

Answer 7

only for a little while because the atmosphere is to to thin and would just boil away.

Answer 8

The scientists found out not to long ago that the some sand from Mars was wet.  So there is a possibility.