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More evidence is consistent with possible ancient life on Mars (2025)

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Re: More evidence is consistent with possible ancient life on Mars (2025)

#131

Post by nephihaha »

somedude89897 wrote: post #75
nephihaha wrote: post #42

Earlier quoted context omitted.

I don't think it was weak at all. We got two positive results from the Viking landers and then tried to explain them away. There is a lot of circumstantial evidence, which combined builds up a case. The public believe we should be looking for cities and skeletons, when in fact we should be looking for extremophiles. It is possible that some of these are due to cross-contamination within the solar system (before human…

The two Viking landers, 6500km apart, had positive results. That would suggest that life is widespread and close to the surface. But the atmosphere of Mars is in chemical equilibrium, which means life can't be widespread and close to the surface because it is not affecting the atmosphere. If life is present on Mars it would have to be deep underground, perhaps in a geothermally heated brine lake, which would be very…

There are questions about methane in the Martian atmosphere. Again, there is some ambiguity as to why.

However, we have found life in some very hostile environments on Earth, notably high up in the atmosphere. Planococcus halocryophilus can exist on Earth at -20' C, well within Martian surface temperature ranges, and is tolerant of very salty water. Microbes need a fraction of the resources we do, and some can exist in very small numbers for long periods before better conditions come along. Surface temperatures on Mars have been observed to go over 20' C during the day in some places which may allow for some warmth to penetrate rock and dust. A very hostile environment, to be sure.

https://www.nature.com/articles/ismej20138

Re: More evidence is consistent with possible ancient life on Mars (2025)

#132

Post by hgoel »

amarant wrote: post #119
hgoel wrote: post #105

Earlier quoted context omitted.

There is absolutely no reason for alien life to have evolved the same biological materials that we have. But also, a space faring species that can build an AI probe capable of remaining functioning for the many years an interstellar journey takes, is also likely to be capable of building habitats that can grow their biological materials. It'd be much easier than shipping those materials over from another star.

Quite right! They probably wouldn't have wood, but we do! They might want the wood though, and they might not know how to grow it. From there we can see 2 scenarios. The likelier one hopefully being trade: we could probably teach them to grow wood, and also provide them with seeds, perhaps on exchange for some of their space-faring tech. Alternatively there's the pessimist scenario, where they're not interested in tr…

Why would they need our permission to take it? They can grab the seeds from anywhere on the planet, and they can just watch any farmer and/or forest for a couple of years and see how it works.

Of course this is putting aside any ideas of deciphering our books or tapping into the internet. Not much we'd be able to do to species that can travel the stars.

Re: More evidence is consistent with possible ancient life on Mars (2025)

#133

Post by buck746 »

nephihaha wrote: post #18
api wrote: post #4

Earlier quoted context omitted.

Sending a microscope is easier said than done. Many natural structures can look like bacteria, and vice versa. If there's more complex single celled life then we might see stuff swimming around but that's considered unlikely close to the surface where there's a decent amount of solar and cosmic radiation. If complex life does exist it's probably deep underground or in caves and lava tubes where we can't reach it yet.…

There is a lot of abrasive dust on Mars as well, which poses a problem to any microscope.

Luna is abrasive, essentially like shards of non safety glass. The dust on mars is soft, it's been blowing around since before the dinosaurs died off. The main issue with martian dust is electrostatic charge, but that's easier to manage than lunar dust.

Re: More evidence is consistent with possible ancient life on Mars (2025)

#135

Post by mapontosevenths »

jibal wrote: post #125
jibal wrote: post #70

Earlier quoted context omitted.

But that's obviously not a reason to treat them as a bad thing. It's also not entirely true ... he was awarded those honors because of the quality of his science journalism. FWIW, I think @mapontosevenths is wrong to say that @gojomo's mention of the honorary degrees and being an OOC was "like they're a bad thing" ... their "But it's hard ..." indicates a conflict between those "credentials" and the typo that gojomo…

So many people here have no idea how things work and are far more interested in virtue signaling over an error (and making spiteful downvotes) than in correcting it, so we get ignorant and intellectually dishonest rubbish like > I think readers should take this as an illustrative example of how often people/institutions draped in such quasi-credentials are carelessly wrong on basic things. and > how many people had t…

I just wanted to say thanks for actually taking the time to make the situation better for everyone, rather than complaining.

Re: More evidence is consistent with possible ancient life on Mars (2025)

#136

Post by jibal »

mapontosevenths wrote: post #135
jibal wrote: post #125

Earlier quoted context omitted.

So many people here have no idea how things work and are far more interested in virtue signaling over an error (and making spiteful downvotes) than in correcting it, so we get ignorant and intellectually dishonest rubbish like > I think readers should take this as an illustrative example of how often people/institutions draped in such quasi-credentials are carelessly wrong on basic things. and > how many people had t…

I just wanted to say thanks for actually taking the time to make the situation better for everyone, rather than complaining.

And thank you ... I really appreciate that.

Re: More evidence is consistent with possible ancient life on Mars (2025)

#137

Post by ahazred8ta »

pigpop wrote: post #67
clickety_clack wrote: post #43

Earlier quoted context omitted.

At most points in time resources are scarce and not all life can be supported. At those times beings with a tendency to say “them” will give way to beings who most strongly assert “us”.

Comments like yours make me think that sci-fi shows (and a lot of literary sci-fi) like Star Trek did a grave disservice to our conception of advanced spacefaring civilizations. They were always focused on alien planets , assuming that once a race was able to travel the stars that they would still chain themselves to a gravity well. It's like imagining an industrial society where everyone still lives on a farm like t…

“You mean we all came from Earth?” said Nikolai, unbelieving. “Yes,” the holo said kindly. “The first true settlers in space were born on Earth—produced by sexual means. Of course, hundreds of years have passed since then. You are a Shaper. Shapers are never born.” “Who lives on Earth now?” “Human beings.” “Ohhhh,” said Nikolai, his falling tones betraying a rapid loss of interest. --- Twenty Evocations (1984) Bruce Sterling

Re: More evidence is consistent with possible ancient life on Mars (2025)

#138

Post by throwaway676712 »

pigpop wrote: post #127
throwaway676712 wrote: post #88

Earlier quoted context omitted.

A necessary condition for the emergence of civilization (in its broadest sense, as in the collectively organized reshaping of one's living environment for one's purposes) is a basic level of trust and cooperation. Humans are not naturally prone to bouts of violence like other species and human societies do not tolerate impulsive violence in adults. Instead, the vast majority of human-on-human violence is deliberate:…

>Humans are not naturally prone to bouts of violence like other species That... does not check out. There are plenty of violent people, I've met many.

The key part is like other species and human societies do not tolerate impulsive violence in adults. All societies have rules, customs and/or arbitrage methods to regulate violence and the vast majority of people definitionally abide by them (otherwise there wouldn't be much of a society to begin with). And the vast majority of violence dealt among humans is not impulsive but deliberate (war, feuds, etc.). This is not incompatible with many people having a capacity for violence, only it's usually channeled through these deliberate methods and the extra impulsive outbursts tend to be punished.

Re: More evidence is consistent with possible ancient life on Mars (2025)

#139

Post by pfdietz »

stackghost wrote: post #121
pfdietz wrote: post #120

Earlier quoted context omitted.

Certainly a great deal of energy is released. However, on the time scale of an impact, heat doesn't diffuse in rock very far. Even on the time scale of reentry to an atmosphere heat doesn't diffuse far. It's common for a meteorite that has fallen to Earth, despite the surface having been melted and ablated, to have an inside that is still freezing cold.

Ah, this was the piece I was missing. I assumed the heat of impact and/or re-entry would sterilize just about anything that wasn't an engineered heat shield.

You might also be interested in the story of Lew Allen's Balls (which is much less prurient than the name might suggest). These were pumpkin-sized steel spheres, coated in a thin layer of graphite, that were suspended as close as 10 meters from one of the Teapot nuclear explosions (22 kT) in Nevada. The explosion vaporized about 1 mm of graphite but otherwise didn't damage the spheres much at all.

https://www.youtube.com/watch?v=by1xpy8ob8E (starting around 5:50).

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