Where are the new traders finding this? Welcome

Randomly popped up in my explore feed

@StrayClimb, can you define "Alien"?

@RobertCousineau living off of earth and not the result of near term spread from earth for example from a mars probe

If ancient panspermia it counts

Is anything originating from earth after LUCA disqualified or just after human space travel?

That would be recent spread right? So no. I'm not sure of the Luca issue details

What is your cutoff for 'recent'?

Last 1m years perhaps? Or maybe even more

Example: during Sputnik era an earth bacteria spread onto mars. That is not alien

Example 2: 1b years ago a meteor knocked an earth bacteria to mars where it survived and evolved and now is a new thing. This is a hard case I'm inclined to say YES

Things that go into being truly alien: long time of separation, very different from us

Cases

Example3: a super weird alien life form has secretly lived on earth, which evolved elsewhere totally separately. It's been here for a super long time. That still feels alien even though its life history intersects earth

Ah cool, thanks for explaining, LUCA was like 4Bya so sounds like stuff separated that long ago counts then

yeah it's kind of tough cause I've never thought about it. If we are forks of the same panspermia thing but they're nearly totally diff and in all ways appear alien, it's not that useful to say they're "not fully separate". But if we find a weird bacteria left over in space from sputnik that's surviving, thats not reasonably "found alien life". But it's hard to find a perfect line.

Ancient terrestrial aliens inclusive?

@ThatGuy yes