Comment by pfdietz
21 hours ago
Yes indeed, I've thought panspermia in the Sun's natal cluster is an interesting idea. What could make it even more interesting is that small bodies in our Solar System (and likely its sister systems) were warm enough for liquid water to exist for some millions of years then, so there would be an enormous volume of material in which Origin of Life might have occurred (and, if it did, to then spread after the parent body froze and then fragmented.)
It would make a fine science fictional scenario that could get around the Fermi problem: those 10,000 or so systems could have life, but the rest of the universe not have life.
That's also neat to contemplate, thanks.
I was thinking bigger: if panspermia gets dramatically more viable, then nebula could switch over in their probability distribution from "default sterile" to default teeming.
In this scenario, we could find (related!) life essentially everywhere, and caused by panspermia no less, despite numbers still saying panspermia is wildly improbable for mature stars.
"Default teaming" really isn't viable due to the Fermi problem.
But if OoL is extremely unlikely, the cluster panspermia idea still allows extraterrestrial life to reasonably exist and be reachable, because that life didn't require a separate highly unlikely OoL event.
I think SETI should focus on stars that look like the Sun's siblings.
"Teaming" (social) organisms are also fun, sure. ;)
The Fermi paradox assumes we'd be good at observing aliens, and that aliens will leave evidence that's conspicuous to us. These two statements are roughly equivalent, basically saying there can't be too much "impedance mismatch" between the two.
But again, even besides that, the nebula can still "teem" even though we never see any here on Earth, because the Sun vs nebula math is just so different for interstellar travel too. Many civilizations, seeded from common dirty chemistry, then permanently separated by vast distance as the star migrates out of the nebula.
TL;DR nebula parameter differences solve Fermi even in a teeming universe, but I doubt we'd see the aliens even if they were here. ;)