Water is definitely on Mars. Not just at the poles, but underground. But... There's always a but.

Large Reservoirs Of Water Ice Found On Mars, Says NASA

In a recent study published in the journal Science, researchers from the Arizona detachment of United States Geological Survey reported, with the help of NASA images, that they discovered significant reservoirs of water ice very close to the surface of Mars.

From article, (Human missions to Mars could extract water from the environment by exploiting these ice reserves. Ice could be mined from the deposits or water could be obtained by boiling it out of hydrated minerals. The water could then be used for drinking, or it could be broken down into both hydrogen and oxygen, which could be used as ingredients for rocket fuel and as breathable air respectively.

Yet there is a problem with using the ice deposits that were identified in the study as resources. A recent NASA study was done to find potential landing zones for astronauts, and the cliffs which contain the ice are located around latitudes 55° north or south. Mars explorers are unlikely to use these regions as bases because the Martian winter sees the regions growing dark and cold for long periods of time. As solar power is likely to be one of the primary power sources for explorers, this represents a problem.

 Space scientist G. Scott Hubbard, from Stanford University in Palo Alto, California would like to see if similar deposits of ice closer to proposed NASA landing zones could be found. NASA limited the potential landing zones to within 50 degrees of the equator, and Hubbard wants to see where the cutoff point is. Ice deposits found within the Martian tropics would be a substantial boon to NASA explorers.

Even if the deposits of ice are found near NASA landing zones, there’s no guarantee the water would be clean enough for humans to use. High levels of salt within the ice would demand that astronauts bring desalinating units with them to Mars, adding to the cost of exploration. Even more of a problem is that the water could have perchlorates in them, a branch of chemicals common on Mars that are toxic to people. Water gained from the ice would require special filtration if this turned out to be true. It’s impossible to say what the quality of the ice would be like until more research is done.

Efforts to send manned missions to Mars have plenty of problems to deal with, including the fact that atmospheric electrical charges could end up zapping astronauts or equipment. The puzzle of how to utilize stores of ice on Mars is just one more thing NASA will have to grapple with, but the discovery of the ice stores brings many new possibilities with it, in addition to the challenges.)

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