3 comments on “Stargazing, Martians, and Hugo Chavez

  1. Pingback: Carnival of Space 188

  2. I believe the Martian Connection (Mars-Earth transpermia) could have been much more alluring before. Then people had crustal cooling times in 100s of My AFAIK, or maybe the Last Heavy Bombardment was seen as the likely start of a habitable inner planet. While at the same time non-enzymatic biochemistry was supposed to be agonizingly slow. It may have seemed that an early start on the smaller Mars was a better bet.

    Not that I’m an expert, but IIRC I have seen papers discussing possible and/or likely crustal cooling times in 10s or 1s of My. And some LHB papers has life modeled as a plague, you can’t really get rid of it once it has started.

    At the same time appreciation of hydrothermal vent chemistry has happened. And now there is a paper that shows that biochemistry around boiling temperatures are sped up much more than traditional chemistry thought so can happen in 10s of years, not 100s or 1000s of My.

    Figuring in the larger area of Earth and the likelihood of abiogenesis as a local event, Earth and Mars cooling at the same time would have life appear on Earth before Mars. Adding in crustal cooling times, impactor rates and travel times, it isn’t obvious (to this layman) which alternative is the likeliest even before admitting that much of these figures are poorly constrained. Meanwhile parsimony would have life started here, because it is observed here.

  3. You raise some very good issues, and I doubt that this question will be answered satisfactorily until we can get a LOT of location samples from Mars. However, parsimony (aka Occam’s Razor) does seem to point to considering that it started here since we observe it here, but that seems like circular reasoning. There’s nothing to say it didn’t start elsewhere and take root here — and that would also support the spirit of your reasoning. Occam’s Razor doesn’t preclude the “life began elsewhere and migrated here” idea. It simply asks that we consider the simpler alternatives first before venturing out to the “wilder” ideas.

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