Are those Martian fossils in meteorite ALH84001? (NASA)
“Panspermia” is a hypothesis that life is transferred from planet-to-planet and star system-to-star system through some interplanetary or interstellar means.
But for panspermia to work, this life needs to be sufficiently protected — and, um, kept alive — from the worst the universe can throw at it (such as radiation, cold and vacuum). Alas, when considering interstellar hops, the timescales are likely too long (i.e. millions of years) and said life will be dead on arrival.
We know that Earth Brand™ life is a pretty hardy thing. After all, we’ve tortured terrestrial microbes and mosquito larvae in the vacuum of space to see if they’d pop. Sure enough, when brought back to terra firma the various creatures wriggled and squirmed as if nothing had happened. But these experiments in orbit were carried out over the course of months or years. While this might be suitable for interplanetary transfers, it would take millions of years for an extraterrestrial interloper to traverse even a modest interstellar gap.
Any hitchhikers that were alive on a stellar wind-blown particle will be toast (or, more accurately: freeze-dried, pulverized, mashed-up, DNA-shredded mess) on reaching their exotic destination eons later.
What good are tiny alien fossils when the panspermia model is supposed to seed other worlds with life… that’s actually alive?
Enter a new incarnation of pansermia: “Necropanspermia.”
Conceived by Paul Wesson, of Herzberg Institute of Astrophysics in Canada, necropanspermia is the transfer of the information of life to new worlds, wriggling extraterrestrial bacterium not required.
Assuming alien microbial life has made the trip across interstellar space, died and then fossilized, Wesson reckons the information contained within the long-dead microbe could be used as some kind of template by a hospitable world to use and grow new life. (It’s not quite zombie science, but it’s hard not to say “reanimated alien corpse.”)
Wesson even goes so far to suggest ET’s microbial remains can be “resurrected.”
“Resurrection may, however, be possible.” Wesson concludes in his Space Science Reviews paper. “Certain micro-organisms possess remarkably effective enzyme systems that can repair a multitude of strand breaks.”
Hypothesizing about various forms of panspermia may seem more like a philosophical argument, but Wesson suggests that we might be able to find evidence for necropanspermia if we collect some dust samples from the outermost reaches of the solar system, far enough away from Earth’s biological pollution.
Alas, as the Hayabusa asteroid mission has proven, capturing dust from anywhere in space isn’t easy.
Read more about necropanspermia in my Discovery News article “Life on Earth Spawned by Dead Alien Microbes?”
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