Comment Um, liquid H20 impossible at martian temp/pressure (Score 4) 133
Earth's atmospheric pressure is 1 atm or converting to kPa, 100 kPa. Martian atmospheric pressure is about 1% of Earth's or about 1 kPa (10^3 Pa on the chart). Average Martian surface temperatures at the equator are -53C or 220K. Now looking at our chart again, we see that at this point, water cannot exist as a liquid, but only as a solid (ice). As day/night termperatures shift, water will alternate between solid and gas only, never even passing through the liquid state, and once a gas, not likely to collect on the ground, but remain suspended as ice crystals high in the air. So for now, the collecting frozen water from near the poles, storing it in canisters , and transporting those to any camps remains the only realistic wat of getting water on Mars.