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New findings point to an Earth-like environment on ancient Mars

discover.lanl.gov

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Re: New findings point to an Earth-like environment on ancient Mars

#241

Post by ethbr1 »

dan_mctree wrote: post #184
caseyy wrote: post #74

Earlier quoted context omitted.

I can just imagine Elorp Munk building a space company on Mars a billion years ago to colonize the frozen and inhospitable Earth. Bringing over some germs and then failing to establish a colony… that could make for some great sci-fi.

I wonder if there'd be any good way to confirm or rule out an ancient Martian civilization. Would Martian surface structures be able to last a few billion years? Or would Martian processes be able to make all of them disappear? And how about underground structures?

I read somewhere that for geologic-scale signatures you need something that is:

   - Chemically inert
   - Recognizably artificial w/o context
   - Physically hardy
   - Planet-scale mass-produced
On Earth, apparently "panes of glass" are one of the few things that qualifies.

Re: New findings point to an Earth-like environment on ancient Mars

#242

Post by kaashif »

somenameforme wrote: post #102
xattt wrote: post #63

Earlier quoted context omitted.

At this point, given how much Mars had been roved, why hasn’t some fossil record been discovered yet? At the very least, I would expect something akin to chalk left behind by proto-diatoms that had calcium carbonate skeletons.

Other posts answered, but only if you already know the answer. The rovers we've used on Mars have done an extremely superficial job of scouring the planet. The most recent rover Perseverance has, to my knowledge, the most capable drill with a max depth of 2.4 inches. [1] And the drill is used extremely sparingly because it tends to break quickly, as it did on Curiosity. And of course it can only drill, not excavate/c…

I am imagining an astronaut digging with a shovel and 2.5 inches below the surface are just dinosaur skeletons and stuff. Or something even more fantastical.

Re: New findings point to an Earth-like environment on ancient Mars

#243

Post by nonethewiser »

throw4847285 wrote: post #166

Sometimes I wonder if Sci-fi has done more harm than good. It provides conclusions that people so badly want to prove true that they will look for any evidence, however meager, to bolster their arguments. Maybe there was life on Mars, but the main motivation to believe that right now is that many people have read about it in fantasy books. Much more devastatingly, Sci-fi has driven what technology people develop, and…

Can you substantiate the claim that scifi is the biggest contributor to people thinking mars might have had life? Seems like a bold claim.

Mars is the 2nd most habitable planet in the solar system and people have wondered if there was life out there for a lot longer than scifi has existed.

This article has plenty of such examples. First one I see it Democritus around 400 bc. https://en.m.wikipedia.org/wiki/Extraterrestrial_life

Re: New findings point to an Earth-like environment on ancient Mars

#244

Post by lugu »

elorant wrote: post #175

This is scary on two fronts. One, whatever happened to Mars could happen to Earth, and two, it puts the Great Filter probably in our future. If our solar system had two hospitable planets then there should be plenty of Earth like planets around in our galaxy. In which case we end up with the Fermi Paradox. If life is so abundant in the Universe how come we haven’t been in contact with aliens?

The Fermi paradox calculations consider that life started on an earth like planet. But have we confirmed that life can appear on an earth like planet?

Re: New findings point to an Earth-like environment on ancient Mars

#245

Post by nonethewiser »

bmitc wrote: post #232
gloryjulio wrote: post #227

Earlier quoted context omitted.

Just a curious question, is Earth's core cooling off like Mars?

I sure hope not. I would assume it's a rather dynamic situation of various periods of different relative behavior. We're certainly at its mercy though. My understanding about Mars is that it is just a much smaller planet than Earth, and it's core composition was slightly different (?), and so the core couldn't keep up and just slowly stopped "slushing around" and cooled off. That's my very loose understanding of the…

So many fortunate series of events that lead to the opportunity for life. Some survivorship bias I guess.

Re: New findings point to an Earth-like environment on ancient Mars

#246

Post by [deleted] »

lugu wrote: post #244
elorant wrote: post #175

This is scary on two fronts. One, whatever happened to Mars could happen to Earth, and two, it puts the Great Filter probably in our future. If our solar system had two hospitable planets then there should be plenty of Earth like planets around in our galaxy. In which case we end up with the Fermi Paradox. If life is so abundant in the Universe how come we haven’t been in contact with aliens?

The Fermi paradox calculations consider that life started on an earth like planet. But have we confirmed that life can appear on an earth like planet?

[deleted]

Re: New findings point to an Earth-like environment on ancient Mars

#247

Post by deelowe »

baja_blast wrote: post #86
deelowe wrote: post #30

Earlier quoted context omitted.

Read the wikipedia link and it seems there are credible explanations for what is going on: > "With unsterilized Terrestrial samples, though, the addition of more nutrients after the initial incubation would then produce still more radioactive gas as the dormant bacteria sprang into action to consume the new dose of food. This was not true of the Martian soil; on Mars, the second and third nutrient injections did not…

> This was not true of the Martian soil; on Mars, the second and third nutrient injections did not produce any further release of labeled gas But that's probably because martian microbes are less tolerant of high temperatures when compared to Earth microbes. But, yes I am aware there are other non life factors that could have resulted in a positive detection. But my point is why would we never follow up with further…

Because we have enough evidence already to draw conclusions? Space exploration is expensive.

Re: New findings point to an Earth-like environment on ancient Mars

#248

Post by nonethewiser »

killthebuddha wrote: post #223
mewpmewp2 wrote: post #210

Earlier quoted context omitted.

I don't understand Fermi Paradox. Why couldn't the chance of life be extremely miniscule, e.g. given all billions of stars and planets, why couldn't there have been even 10% or 0.0001% odds of it happening at all one any given stars or planets? E.g. maybe even it happening on one was such a lucky occurrence? Maybe given even 1,000,000 of observable universes the odds were just 1 out of 1,000,000. How can people confi…

> To me it seems like the probability could have been anything. The point is that we do know some things about the universe and, given what we do know, we think the probability is high. So we're obviously missing something but we don't know what. The thing that makes the Fermi Paradox so interesting is that every resolution is either interesting or implies something interesting.

> So we're obviously missing something but we don't know what.

Isnt the answer dead simple though? Space is mostly empty. Everything is very far away and getting even further as the universe expands. If there were bits of life scattered around the universe I wouldnt expect contact between them.

The paradox seems to rely on the assumption that if aliens existed they would have colonized the entire universe by now but that seems like a huge leap when we look at ourselves.

Universe is almost 14B years old. Life on earth is almost 4b years old. There have been several mass extinction events which almost completely whiped out life. There are planets in our system that may have had life but would have died off a very long time ago. Its kind of remarkable that we are here and how much progress we’ve made. We are certainly fitter than average (survivorship bias proves that). Yet we are nowhere even remotely close of expanding out into the solar system and beyond. And how could we, if virtually all of that space is void of resources we need to survive? Why is it inevitable that some alien would have solved that?

Re: New findings point to an Earth-like environment on ancient Mars

#249

Post by acchow »

ceejayoz wrote: post #149
iamthirsty wrote: post #146

Earlier quoted context omitted.

> Hundreds of tons of rock like this from Mars land every year. 277 total Martian meteorites — with the largest weighing 14.5 kg — is not hundreds of tons yearly.

That's how many have been conclusively classified as Martian out of "the 72,000 meteorites [total] that have been classified". ( https://en.wikipedia.org/wiki/Martian_meteorite ) That's obviously not the actual total that have ever made it here. https://science.nasa.gov/solar-system/meteors-meteorites/fac... > Scientists estimate that about 48.5 tons (44,000 kilograms) of meteoritic material falls on Earth each day.…

> Scientists estimate that about 48.5 tons (44,000 kilograms) of meteoritic material falls on Earth each day.

Most of it gets destroyed on entry, right? No organic matter surviving?

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