As others have noted, geothermal vents could provide a place for life to get started, as it is thought to have occurred here.
One thing that I think is important to consider is that what is really needed is an energy gradient which can be leveraged to do the work of creating all the different kinds of compounds one would need to produce something we'd call "alive".
I think the other article from quanta about "assembly theory"[1] is a good one to consider in this context. What would be the "Assembly Contingent" of a world like Europa or these other moons?
My guess would be that there might be enough material and energy potential to allow pathways to bacteria analogues (not that these def exist, but they're possible), but not nearly enough to support the variation and specialization required to reach multi-cellular life.
Something I learned recently. There exists a 1967 international treaty that no space exploration can touch external water of any sort to prevent earth duelers from contaminating water outside Earth.
Coincidentally Outer Space Treaty has same signatories as 1994 Budapest Memorandum on Security Assurances. Feel free to look up how that last one worked out.
Getting to these planets or moons that have water in the first place is already hard, getting back from them is pretty much such a big nonstarter at the moment it's not worth thinking or worrying about.
Life can find energy to run near hydrothermal vents[1], or naturally occurring nuclear reactors [2], or perhaps exploiting tidal heating[3].
I would also be not surprised if there are ways to run life on much lower energy gradients than what we are accustomed to here on Earth. Some weird biochemical tricks, perhaps a much slower life cycle. I don't know how that would look like, I'm just saying simply "Life..ehm..will find a way".
Yes, I agree. My personal favorite candidate for alien life is Europa, which is real cold, real barren, and not sunny on the outside, but probably has a nice warm salt water ocean inside with all kinds of hydrothermal vents and tidal heating.
There's probably twice as much water in Europa's ocean than there is on all of Earth.
Discovering life on other planets would be at least a Copernican-level shift in most sciences. I think it'd be the discovery to trump all other discoveries.
I can't decide what's weirder: That it'd use similar DNA/RNA for replication, or that it wouldn't.
I think they would both be massive discoveries that would shake things up. If it used DNA/RNA it's almost certainly from the same tree of life as us, validating the panspermia theory. If it didn't then we'd get to see a completely novel chemistry of life, although still water based.
If there is liquid water, it means it's not colder than the antarctic sea, which holds a lot of life. Unless there is some weird pressure + salt shenanigans I don't know about.
This is why it would be really interesting to find out if there's any life in the lakes underneath Antarctica[1]. This would probably show life is possible on these moons.
> It’s just so damn cold out there, how could life start/survive.
"On Earth, the ocean floor is home to hydrothermal vents that spout hot water, nourishing life in an otherwise inhospitable environment. Scientists think similar vents could exist on other worlds such as Jupiter's moon Europa and Saturn's moon Enceladus."
Earth is average 287 Kelvin. Mars can just about keep hold of all CO2 at that temperature. A smaller body would need to be colder to hold on to the same materials, or some other method of reducing escape.
Unlikely. The moons of Uranus appear to not have atmospheres.
There is this cool paper[1] about how they measured the lack of atmosphere for one of the moons (Titania). They measured carefully the light of a star as the moon occluded it. If there were atmosphere there they would have seen it.
No atmosphere, no runaway greenhouse gas process. At least not how we know it.
Sunlight is entirely irrelevant for the habitability of any of these internal oceans, including Europa’s. The pertinent energy sources are internal heat and tidal interactions, distance from the sun does not matter at all.
Life on Earth is posited to have begun with a primordial soup of the right chemicals and it began with microscopic stuff. My recollection is viruses are not deemed to fit the definition of "alive" yet contain RNA and two strands of RNA equals DNA, the code for more complex life forms.
It's quite the elegant system.
Also, there are microbes found in volcanic vents and in Antarctica. I don't think temperature is big a limiting factor as you seem to think.
> It’s just so damn cold out there, how could life start/survive.
It won't always be this way. The sun is destined to become a red giant, which may put the Solar System's distant watery and icy moons in a comfy habitable zone.
For Greek speakers it just means “sky” so no big deal. The namer of the planet was German (Johann Bode) so he wouldn’t have known its unfortunate double meaning in English. Every time you say it it’s like a punchline.
One thing that I think is important to consider is that what is really needed is an energy gradient which can be leveraged to do the work of creating all the different kinds of compounds one would need to produce something we'd call "alive".
I think the other article from quanta about "assembly theory"[1] is a good one to consider in this context. What would be the "Assembly Contingent" of a world like Europa or these other moons?
My guess would be that there might be enough material and energy potential to allow pathways to bacteria analogues (not that these def exist, but they're possible), but not nearly enough to support the variation and specialization required to reach multi-cellular life.
[1] https://www.quantamagazine.org/a-new-theory-for-the-assembly...