Friday, April 24, 2009

History Channel: "Asteroids" in "How the Earth Was Made" series


I’ve talked about History Channel films on asteroids in connection with the possibility of disaster – and indeed we could face one in 2029, according to the latest.

The “How the Earth Was Made” episode "Asteroids" aired on April 21, 2009 started out by examining Meteor Crater in Arizona (there is another one near Odessa Texas that I have seen more often). But this film went on to cover the “good” done by meteors from asteroids – oil deposits in the Gulf, a nickel mine in Ontario (way north of where most of the road maps show) and a gold mine in South Africa. The basic link is here.

The History Channel has its own “encyclopedia” article that discusses carbonaceous chondrites that sometimes contain amino acids as well as water and other carbon compounds. I’ve talked about History Channel films on asteroids in connection with the possibility of disaster – and indeed we could face one in 2029, according to the latest.

The History Channel has its own “encyclopedia” article that discusses carbonaceous chondrites that sometimes contain amino acids as well as water and other carbon compounds.

If so, where could the amino acids have come from? We’ve heard about the Antarctic discovery of a rock that apparently came from Mars and that had possible “tubules” associated with bacteria-like life. There could be amino acids on Titan, or perhaps in the atmospheres of the gas giants. But it seems more likely that they come from other solar systems. About 30 light years away or so, there are number of Class M stars, some of which are likely to have earth-like planets. They would be smaller than Earth and may face their parent stars all the time (at least as suggested on a National Geographic Film “Extraterrestrials” in 2005 and another History Channel film “Alien Worlds” in 2008, with the fictitious planet "Arinelle"). That would mean that any civilization would live in a twilight circle slightly smaller than the diameter great circle of the planet (but there could still be a tilt and therefore there could be seasons). Because M stars are more common, this sort of situation may happen frequently in the galaxy. Amino acids from such a system might take a hundred thousand years or so to reach us through deep space.

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