By now, I'm sure you've heard there's water on Mars. Free-flowing, very salty water. The announcement came a day or two after I saw "The Martian", and I decided to dig deeper into this Martian water issue.
In the late 19th century, Giovanni Schiaparelli reported seeing 'canali' on Mars' surface, meaning channels. A few years later, Percival Lowell confirmed long lines on Mars' surface, and suggested they were an attempt by an advanced Martian culture to save their drying planet by moving water from the poles. Ultimately, these canali / canals did not exist. I haven't found any explanation for why or how they were 'seen' in the first place.
Most of Mars' northern hemisphere is fairly flat with few impact craters; the southern is covered in impact craters. In between is an area of mesas, flat-floored valleys with cliff walls, and other rough terrain. Some features imply that water was present in the distant past, that free-flowing water created paths through the stones. Where did it all go?
Some is still there. Surrounding the bases of those mesas and at the bottoms of those cliffs are what appear to be masses of rock, called lobate debris aprons. In Alaska, we saw a glacier that was so covered in dirt and rocks (picked up during its travel), it just looked like a muddy pile on the edge of the bay. That's what these debris aprons are... solid ice covered in rocks and dirt.
Recent reports from SPICAM, which is circling Mars to study its atmosphere, show that the Martian atmosphere is super-saturated with water vapor. Water vapor doesn't just form droplets when it gets chilled, it needs a speck of dust or something to condense around. If there isn't enough dust, the vapor keeps pushing upward. Eventually, that vapor gets so high, it splits into hydrogen and oxygen, which escape into space, but the article I read said even at 50 km, the atmosphere was super-saturated.
So, Mars is not the super-arid place we thought it was.
How would that have changed the survival techniques used in "The Martian"? In his attempt to produce water to grow crops, could he have 'mined' it from one of these rock piles? Devise a method to condense it from the air? Purified the salty stuff?
What do you think?