Hey, other people know much, much more and can explain what they know more clearly…but I had some spare time today.
A long time ago on Mars, according to the evidence, there was intermittent liquid water in many places, and near Gale Crater, where the Curiosity Rover has been traveling:
‘The data indicate the Yellowknife Bay area the rover is exploring was the end of an ancient river system or an intermittently wet lake bed that could have provided chemical energy and other favorable conditions for microbes. The rock is made up of a fine-grained mudstone containing clay minerals, sulfate minerals and other chemicals. This ancient wet environment, unlike some others on Mars, was not harshly oxidizing, acidic or extremely salty.’
Conditions don’t look terrible for having once harbored some sort of microbial life, but finding such evidence of that life is another matter.
Why is the atmosphere so thin and how did it get that way? Why is any water now locked, frozen, beneath the northern polar ice-cap?
3.8 billion years ago, according to a new paper and press release, it’s possible to explain why an atmosphere a little thinner than that of Earth at one point, could eventually thin to just 1% that of Earth.
‘Modeling the long-term effects of this “ultraviolet photodissociation” mechanism, the researchers found that a small amount of escape by this process leaves a large fingerprint in the carbon isotopic ratio. That, in turn, allowed them to calculate that the atmosphere 3.8 billion years ago might have had a surface pressure a bit less thick than Earth’s atmosphere today.
“This solves a long-standing paradox,” said Bethany Ehlmann of Caltech and JPL, a co-author of both today’s publication and the August one about carbonates. “The supposed very thick atmosphere seemed to imply that you needed this big surface carbon reservoir, but the efficiency of the UV photodissociation process means that there actually is no paradox. You can use normal loss processes as we understand them, with detected amounts of carbonate, and find an evolutionary scenario for Mars that makes sense.”
This is beyond the level of hostility found in even extreme environments here on Earth (summit of Everest, Anarctica). Survival here would be no joke.
A few missteps, or a simple error in judgment could lead to death. An unfortunate series of malfunctions in critical systems could lead to death. No cargo transport’s on the way. Any life we send must be able to sustain and provide for itself.
Aside from these rovers, this planet is beyond all known human experience. There would be no signs of life; bleak, stark, alien and beautiful.
Let’s do it!