Traces of ancient ocean discovered on Mars • Hacker News Board

Re: Traces of ancient ocean discovered on Mars

#21

Post by biren34 » Mon, Oct 31, 2022, 8:55 AM UTC

atoav wrote: post #8

mach1ne wrote: post #7

Mars lost all of its (surface) water presumably due to solar wind, and thus never had time to evolve complex life. Earth would have faced the same fate were it not for the fact that the Moon collided with us at some distant point in time, surrendering its iron core to ours. Now, our Rare Earth has an unnaturally large active iron core, resulting in an unnaturally efficient magnetic field which is able to protect our…

One might be inclined to attribute the amount of good luck to devine intervention, but to this I would say: If the conditions on our planet would not have allowed for higher life, nobody would have been there to ask themselves why the conditions were slightly off.

If you haven't heard of it, you've just stated the weak anthropomorphic principle.

Re: Traces of ancient ocean discovered on Mars

#22

Post by varjag » Mon, Oct 31, 2022, 9:04 AM UTC

MattPalmer1086 wrote: post #18

varjag wrote: post #13

Earlier quoted context omitted.

But you only introduce an unnecessary extra step in the same theory. Life still had to evolve somewhere, just that now it had to embark onto interstellar trip.

Not entirely unnecessary. It's a big question as to why life started on Earth as soon as it did, pretty much as soon as it was even possible. That could be because life is very easy to start if conditions are right. In which case it's quite likely to have started on early Mars too, and we should expect to find at least simple life all over the place. The other possibility is that it didn't start on Earth, and was see…

Why not add more steps? The aliens¹ brought microbial life on an interstellar ship and seeded it. A lot better chance than riding out for a few million years on a piece of rock! See, it's approximately on the same trailing end of unlikely as panspermia, but I fancy this one more.

¹Let's call them Engineers

Re: Traces of ancient ocean discovered on Mars

#23

Post by pimbrah » Mon, Oct 31, 2022, 9:10 AM UTC

biren34 wrote: post #21

atoav wrote: post #8

Earlier quoted context omitted.

One might be inclined to attribute the amount of good luck to devine intervention, but to this I would say: If the conditions on our planet would not have allowed for higher life, nobody would have been there to ask themselves why the conditions were slightly off.

If you haven't heard of it, you've just stated the weak anthropomorphic principle.

*anthropic

Re: Traces of ancient ocean discovered on Mars

#24

Post by ratg13 » Mon, Oct 31, 2022, 9:21 AM UTC

mach1ne wrote: post #7

Mars lost all of its (surface) water presumably due to solar wind, and thus never had time to evolve complex life. Earth would have faced the same fate were it not for the fact that the Moon collided with us at some distant point in time, surrendering its iron core to ours. Now, our Rare Earth has an unnaturally large active iron core, resulting in an unnaturally efficient magnetic field which is able to protect our…

Seems like a bit of a stretch to say with certainty that Mars never evolved complex life 500+ million years ago.

Re: Traces of ancient ocean discovered on Mars

#25

Post by treeman79 » Mon, Oct 31, 2022, 9:42 AM UTC

trophycase wrote: post #19

ramraj07 wrote: post #10

It’s beyond obvious that water flew as rivers in Mars at some point, and looks like there’s some water there even now! Even life, is there any reason to think there WASNT some microscopic life there at some point? I doubt anyone thinks there’s viable life there even now (though one can’t 100% exclude the possibility). It’s like everyone kind of already knows these are the likely facts but we keep using these as scape…

So agree, but the logistical challenges for even landing a probe on somewhere like Europa or Enceladus are far greater than landing somewhere as inert as Mars. Jupiter has an incredible magnetic field, we'd need to somehow land on the moon (which is a challenge in itself due to the potential for 30m spires of ice), drill through the surface ice and possibly through multiple subsurface oceans til we reached a layer th…

I always gave this vision of 20 years after sending a probe the moon turns green. Liquid sub surface ocean being an excellent breeding ground.

Re: Traces of ancient ocean discovered on Mars

#26

Post by mach1ne » Mon, Oct 31, 2022, 9:55 AM UTC

varjag wrote: post #13

ramraj07 wrote: post #11

Earlier quoted context omitted.

I have very little reason to believe life evolved in Earth or even in Mars for that matter. The more likely scenario is that there’s rocks floating around everywhere that have spores of life throughout the galaxy ready to seed a suitable planet in geologically instantaneous timelines. That will explain the extremely rapid emergence of life on earth initially while it took a few billion years to evolve any further. In…

But you only introduce an unnecessary extra step in the same theory. Life still had to evolve somewhere, just that now it had to embark onto interstellar trip.

But instead of having a single planet generating random molecular combinations to roll for proto-DNA, you have billions or more. Life would have to evolve extremely commonly for it to be more probable to evolve by itself on any specific planet than on literally any planet which then encouters an event causing panspermia.

But alas, that's an external observer viewpoint. It's important to note that it does not say that life is more probable to have evolved somewhere else than Earth (since we have an effective sample size of 1). It only says that the extra step introduced in the panspermia theory does not have a negative probabilistic impact, on the contrary.

Re: Traces of ancient ocean discovered on Mars

#27

Post by AareyBaba » Mon, Oct 31, 2022, 10:01 AM UTC

MattPalmer1086 wrote: post #18

varjag wrote: post #13

Earlier quoted context omitted.

But you only introduce an unnecessary extra step in the same theory. Life still had to evolve somewhere, just that now it had to embark onto interstellar trip.

Not entirely unnecessary. It's a big question as to why life started on Earth as soon as it did, pretty much as soon as it was even possible. That could be because life is very easy to start if conditions are right. In which case it's quite likely to have started on early Mars too, and we should expect to find at least simple life all over the place. The other possibility is that it didn't start on Earth, and was see…

The big question is how local regions of low entropy that exhibit metabolism and replication (ie. life) came into existance out of inanimate matter. Where it happened is secondary.

Re: Traces of ancient ocean discovered on Mars

#28

Post by atoav » Mon, Oct 31, 2022, 10:06 AM UTC

biren34 wrote: post #21

atoav wrote: post #8

Earlier quoted context omitted.

One might be inclined to attribute the amount of good luck to devine intervention, but to this I would say: If the conditions on our planet would not have allowed for higher life, nobody would have been there to ask themselves why the conditions were slightly off.

If you haven't heard of it, you've just stated the weak anthropomorphic principle.

Thanks, I did not know there was a term for this idea.

Re: Traces of ancient ocean discovered on Mars

#29

Post by zokier » Mon, Oct 31, 2022, 10:30 AM UTC

ramraj07 wrote: post #10

It’s beyond obvious that water flew as rivers in Mars at some point, and looks like there’s some water there even now! Even life, is there any reason to think there WASNT some microscopic life there at some point? I doubt anyone thinks there’s viable life there even now (though one can’t 100% exclude the possibility). It’s like everyone kind of already knows these are the likely facts but we keep using these as scape…

> Even life, is there any reason to think there WASNT some microscopic life there at some point?

Well the little thing of not having any evidence indicating the presence of life.

Re: Traces of ancient ocean discovered on Mars

#30

Post by mach1ne » Mon, Oct 31, 2022, 10:37 AM UTC

ratg13 wrote: post #24

mach1ne wrote: post #7

Mars lost all of its (surface) water presumably due to solar wind, and thus never had time to evolve complex life. Earth would have faced the same fate were it not for the fact that the Moon collided with us at some distant point in time, surrendering its iron core to ours. Now, our Rare Earth has an unnaturally large active iron core, resulting in an unnaturally efficient magnetic field which is able to protect our…

Seems like a bit of a stretch to say with certainty that Mars never evolved complex life 500+ million years ago.

Fair point, but even with rovers we have zero indication to the fact, and thus it's a very reasonable estimate.