101–110 of 139 posts
It would not be surprising if ancient life did exist on Mars, since impacts would likely have sent life back and forth between Earth and Mars (and possibly Venus). For the same reason, the existence of ancient life on Mars would not show that life is likely to arise on Earth-like worlds, since one could not conclude it was an independent event.
Tangential, but really looking forward to what Europa Clipper[0] finds in its flybys. The delay in communication makes ambitious manoeuvres challenging - perhaps advances in AI (and by extension robotics) helps build much more autonomous space rovers. This could enable us, for example, to evaluate the samples by sending wet microscopes with the rover itself. [0]: https://science.nasa.gov/mission/europa-clipper/
Tangential to your tangential: The era of AI makes me realize that if we ever get visited by aliens: it will probably not be actual aliens -- just an AI probe. And the idea of it really intrigues me. Imagine some LLM that is many generations ahead of Fable -- but from a different world -- visiting us. It would be amazing. And it would likely be better at figuring out how to communicate with us (than the human-equival…
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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…
In his novel Aurora , Kim Stanley Robinson challenged this view by suggesting that at the small scale of orbital structures, there may be insurmountable obstacles to biological life, like the buildup of salt through waste. His ultimate conclusion was that “life is a planetary phenomenon” (and we should take better care of the planet we have).
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The scarcity view of life is so deeply ingrained in some of us that its become an entire world view. Some folks cant even imagine a post scarcity society. Try though. Space is mind blowingly large and anything with the ability to traverse interstellar space alteady has access to unlimited resources and energy, likely closer than us. We live in a tiny backwater of the galaxy. We literally have nothing of value to such…
Some sci fi author (I forget who) pointed out that in a space faring society, the most valuable materials are biological materials. Once you have access to comets and planets, you'll have, for all intents and purposes, an infinite supply of gold, diamond, ruby, etc. Wood however... You're not gonna find a lot of wood in space.
It would not be surprising if ancient life did exist on Mars, since impacts would likely have sent life back and forth between Earth and Mars (and possibly Venus). For the same reason, the existence of ancient life on Mars would not show that life is likely to arise on Earth-like worlds, since one could not conclude it was an independent event.
In some ways the more interesting question might become whether Martian life, if found, shares the same basic biochemistry as Earth life
It would not be surprising if ancient life did exist on Mars, since impacts would likely have sent life back and forth between Earth and Mars (and possibly Venus). For the same reason, the existence of ancient life on Mars would not show that life is likely to arise on Earth-like worlds, since one could not conclude it was an independent event.
>impacts would likely have sent life back and forth between Earth and Mars By what mechanism is an impact giving some debris on Mars enough delta-V to reach Earth, without obliterating Mars and also sterilizing the debris due to heat and plasma?
Impact spallation.
When the strong shock wave generated in rock by an impact hits a rock/atmosphere (or rock/vacuum) surface, it is reflected, producing strong tensile stress. This causes very large acceleration while not subjecting the spalled layer to extreme temperature or pressure.
This is the same process that HESH (High Explosive Squash Head) antitank rounds use to defeat tank armor without penetration. The explosive squashes against the armor before detonating, launching a shock through it causing material to spall off the inner surface at high speed. The shock here is weaker than in the impact case, however.
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Our values are murderous, I wouldn't want to be visited by aliens that shared out values. A galactic version of human society would quite reasonably identify that earth couldn't fight back then special interests would have our planet liquidated for its natural resources without making headlines in space-news. Possibly colonise us, kill all the humans then offer an apology a few generations later and maybe a small loc…
I don't see why an intelligent alien species would have similar values to us. It would depend entirely on their social organization so unless they were the exact equivalent of us evolutionarily (omnivorous, sexually dimorphic, social, bipedal, terrestrial, etc.) they would value the lives, property, territory and status of their own kind and other animals very differently. A race of aquatic arthropods could be mostly…
Damn, I really enjoyed that book. Best of the series so far, in my opinion.
The article is good but the title is a bit too slippery a statement in my opinion. The article is saying more evidence is consistent with possible ancient life on Mars. In astrobiology the massive problem is that geology can imitate biology. The presences of minerals formed by microbes on Earth does not prove microbes are involved in their production on Mars, it is a big jump to make.
That bar is pretty low. I am not hard to convince.
We don't have a baseline by which to contextualize the situation statistically. There is no p-value we can meaningfully satisfy. Worse than that, evidence required for a belief derives from the risk of being wrong.
Is there a discussion of what evidence WOULD be enough for the scientific community to say loudly "There was life on mars". Because right now it seems all risk and no utility, so the evidence bar would be really high.