Life on Mars

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This article caught my eye. The Mars rover Opportunity discovered signs that Mars once had water “you could drink” and probably was “much more favorable in its chemistry, in its pH, in its level of acidity, for things like prebiotic chemistry.”
This took me by surprise because everything that I’ve read suggests that abiogensis, spontaneous generation of life, theories are focused on environments rich in prebiotic chemicals. In other words, water has to be polluted to kick off the reactions that produce the building blocks of life.

schematic of Miller-Urey experiment. Subsequent research showed that the gases they used were not representative of the primordial atmosphere.

schematic of Miller-Urey experiment. Subsequent research showed that the gases they used were not representative of the primordial atmosphere.


The most well-known example is the Miller-Urey Experiment. Urey, Nobel laureate chemist, and grad student, Miller, sparked electricity through a flask that contained water and a mixture of gases, which they thought were equivalent to Earth’s primordial atmosphere: methane, ammonia, and hydrogen. All are reactive gases, i.e. you expect something to happen if you spark energy through the mixture. The experiment quickly produced one building block of life, the amino acid, glycine. Glycine is a heck of a long way from a living cell, but the early success was encouraging and suggested that that the scientists were on the way to showing that life could have spontaneously spawned on Earth. Further experiments yielded other amino acids, still very basic, still not anything close to a living cell.
By the 1960’s, the geological understanding of Earth’s early atmosphere had gotten better and scientists knew it wasn’t methane and ammonia, but rather that it had hardly any of the two chemicals—nix on the initial Miller-Urey hypothesis. This knowledge sent abiogenesis scientists looking for other places where the chemistry might be conducive to forming the necessary compounds, which would bootstrap themselves into the first living cell. Deep ocean volcanic vents, water soaked mineral beds deep in Earth’s crust, and debris from organic clouds in outer space are just a few theories proposed.
No one suggested pure potable water. It doesn’t have the assortment of chemicals needed to support the necessary reactions. If pure water were the place where life might self-create then new life forms should be popping up in mountain streams and lakes, and, of course they aren’t.
So what did the scientist in the article mean? Read the article carefully. The key point is that this ancient water was better than anything else that the rovers found on Mars. It sounds like the others were too acidic.
If our civilization survives long enough, I have no doubt, we will create life and that our machines will reach the planets of other stars. I expect that any day we will have proof that life did exist on Mars. Once we learn that, then the probability that Mars debris brought life to Earth will increase tremendously. In general, as we learn more about Mars, and stars and their planets, the probability that life came to Earth from another place goes up, and of necessity, the probability that it generated here will go down.
Of course panspermia has its problems. I wonder how life could survive near absolute zero in deep space and then fire ball temperatures as it plunges through our atmosphere eventually to deposit here. On the other hand the origins of life experiments are like making an abacus and claiming it proves that a supercomputer could create itself from billions of abacus beads, using only random trial and error, of course.
And of course, the counterargument is, “Well it had to spontaneously generate somewhere.” True, but maybe when you see where, you’ll know how.
Here are some sources of information about origin(s) of life experimentation:
Great Courses
Wikipedia

2 thoughts on “Life on Mars

  1. We watch human kind stumble forward through geological and then historical time and believe it will go on forever. Yet science that seeks extraterrestrial intelligence concerns itself with the extinction rate of advanced societies. Such things as gamma ray bursters exist and are believed capable of sterilizing entire biospheres. As some say, the universe is a bad place to live. Whether we or any other society lasts long enough to create life is a long shot. On the other hand, with billions of stars, even a long shot might eventually make it.

  2. Blake, you always throw out thought-provoking theories. The possibility that we could create life (other than by the traditional birth method) is mind-boggling. I’ll be thinking all day about the ramifications.

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