Traces of ancient ocean discovered on Mars
phys.org
phys.org
Without the event we'd have a planet even smaller than mars!
https://phys.org/news/2017-12-doesnt-venus-magnetosphere.htm...
I don't know that the collision with the moon is the secret here or not. I think it's complex.
I don’t know enough to know if that supports the GP’s conclusion or not, but it may.
Mercury has no magnetic field, and no meaningful atmosphere like we'd understand it. Venus has a minimal magnetic field, and is covered in hot dense CO2 layer because the solar wind blew away all the hydrogen and continues to blow away the atmosphere. The Earth has a much stronger magnetic field that has protected our oxidized hydrogen, and good evidence points to the giant impact hypothesis.
Source: biologist but not specializing in evolution.
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.
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 seeded from somewhere else.
¹Let's call them Engineers
1. How exactly are these spores of life getting into asteroids and being pinged around the Universe? The mechanism seems absurd to me. Earth is teeming with life, but outside of our explorations I believe none of it escapes our planet at all.
2. The life that would reach us would be already specialised for whatever environment it came from, and I would imagine would result a lower amout of variety, since it's already a successful species. But on our planet we have a massive amount of variety, which I believe points more to a bootstrapped start where competition was less intense, and odd things could develop, which were later outcompeted (see the Cambrian explosion).
Disclaimer: Not even a biologist, but I'm more willing to accept that life started and evolved here. Of course that might all be cast in doubt if we detect masses of life on asteriods or metoerites, but the first attempt at that seems to have come up with nothing so far.
Remember that while you deal with insane numbers on the space side, viz. it’s emptiness, the number of planets etc., you’re meeting an insane adversary with biology as well. The number of cells in a single piece of sand in this planet is insane. The number of particles we might eject if there’s a catastrophic event from earth is insane. Anyone who worked on biology would know how hard it is to keep things truly sterile. I’m just extending it to outside space as well.
As for the conditions being too specific, while it’s true, I don’t see many outrageous combinations you can commonly observe in planets in the galaxy so I’m not sure if that’s a big deal breaker.
The only data point we have suggests the evolution of eukaryotic cells and multicellular life is simply less likely than abiogenesis. There are plenty of hypothesis to explain why that might be the case.
Considering we believe this happened to earth, it's not unreasonable to think the same happened to Mars at least once.
“We need boots on the ground to back the good science behind these findings.”
Why is wanting to send people to mars to confirm or leverage these findings so offensive?
What also gets to me is that clearly people have done this cost-benefit analysis before - people that know a lot more about the topic than me. It lacks humility to ignore their reasoning (see https://spacenews.com/independent-report-concludes-2033-huma...).
How do we turn this into a meaningful political movement? My strongest pro argument in a political context is resource security and not having to rely on adversarial states. Economically, it means and endless supply of sources we need to build our increasingly complex devices. Also jobs. I see this as an existential benefit for advanced societies. But how do you bring this is front of average joes with the same intensity as current issues.
I feel like space investments are a lot more valuable than most of the stuff politicians care about nowadays, though, so I'd be interested to support a movement like that
What a momentous discovery for humankind that would be!
0: If Loud Aliens Explain Human Earliness, Quiet Aliens Are Also Rare - https://iopscience.iop.org/article/10.3847/1538-4357/ac2369
> Instead of flooding the surface of the fields, and thus wasting immense quantities of water by evaporation, the precious liquid is carried underground through a vast network of small pipes directly to the roots of the vegetation. The crops upon Mars are always uniform, for there are no droughts, no rains, no high winds, and no insects, or destroying birds.
> The crops upon Mars are always uniform, for there are no droughts, no
> rains, no high winds, and no insects, or destroying birds.
In 10 or 15 years if Starship works out we may be able to send scientists to Mars.
I'm a fan of the hypothesis that life on Earth came from Mars - will be very interesting to see how it develops as we study Mars.
It's kind of a mind boggingly huge billiard game.
With a bit of luck, life was somewhere around the initial impact, a couple bits of life survive blast energy, cold of space, radiation exposure, passage of time, atmosphere entry, and impact, and finally feel cozy enough on the new rock to replicate.
Now, the metagame is to assign numbers to all of that, and compare that to the odds of molecules assembling themselves into spawning life locally by itself. Also the latter must have happened somewhere first anyway, the question mostly being which of it is it for Earth.
This seems incredibly far fetched but the time scales are galactic, and so it kind of looks like it happened a few times over but we're not quite sure yet:
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 scapegoat questions to fund more missions for rovers etc. Instead, wouldn’t it be better if we are honest to oursleves and find things we actually want to do? Like get some people there? Which again, more than the science is just about the accomplishment itself.
I’m genuinely curious about places like Europa. I’m not at all curious about digging more Martian dirt and doing increasingly insignificant geology on a dead planet.
Eventually we'll get to a point where we can explore Europa properly and we can send people to Mars, and all that, but it's going to take time. Without enough funding, things just take a lot of time.
Their budget is actually absurdly large. The problem is they are mandated to engage in vanity projects like Artemis, which don't do anything to contribute to science at all.
We have no clue about how likely it is for life to emerge or how it happens, so we can't really tell. Maybe we're on the only planet with life in the universe.
Finding proof of life on Mars would completely change that equation.
Well the little thing of not having any evidence indicating the presence of life.
Also while I agree with you that it's very likely that there was microscopic life on Mars at some point in the past, considering that finding evidence of life on other planets would be one of, if not the largest discovery in human history, I think it's important to keep going until we confirm it.
There's this from 2008:
https://www.space.com/5546-proof-water-ice-mars.html
It seems to show evidence for subsurface ice on Mars now, though I'm not sure if this is H2O ice or CO2 ice.