I think the Mars argument is backwards. The missing magnetic field is the main issue. More regular flares being faster in stripping away the unprotected atmosphere is inconsequential on the time scale we are talking about.
Comment on no chances for life around red dwarfs
FinjaminPoach@lemmy.world 12 hours ago
Red dwarf stars also flare more frequently than our Sun, unleashing waves of ultraviolet and X-ray radiation that is harmful to life as we know it. If the Sun can strip off Mars’ water and dense atmosphere from a huge distance, planets like Proxima b lying about 30 times closer to furiously flaring stars could lose their atmospheres in just a hundred million years. To make matters worse, such planets being tidally locked means their molten interiors likely churn slowly, generating feeble or no magnetic fields. This deprives the planets from the kind of radiation protection that is so effective here on Earth and contributes to its proliferation of life.
In 2014, NASA’s Swift mission caught a red dwarf emitting a flare 10,000 times more powerful than any ever expelled by our Sun. Most newly born red dwarfs may emit such mega-flares, perhaps in revolt against us having judged them on size. The intense radiation from these mega-flares could prevent life from ever arising on nearby planets.
Ooops@feddit.org 11 hours ago
gandalf_der_12te@feddit.org 7 hours ago
also mars does have an atmosphere, it’s just frozen at the poles.
dalekcaan@feddit.nl 8 hours ago
It’s cold outside, there’s no kind of atmosphere
FUCKING_CUNO@lemmy.dbzer0.com 12 hours ago
perhaps in revolt against us having judged them on size.
So Red Dwarfs (Dwarves?) get mad and insecure about being small, and destroy the atmosphere of their local planets? Are they just coal rollers in disguise?
smeg@feddit.uk 7 hours ago
Red Dwarfs (Dwarves?)
Dwarfs if they’re in the sky, dwarves if they’re under the mountain
Asetru@feddit.org 11 hours ago
Paragone@lemmy.world 11 hours ago
Mere-ideas, but…
there seem to be one hell of alot of the things, so therefore some must have captured rogue-planets, after they calmed-down…
that would mean that the atmosphere-stripping might not be universal for all planets orbiting them, only for the planets that orbited them when they were young red-dwarfs…
Being tidally-locked may mean that not having any Van Allen belts may be irrelevant: the radiation they’re being bombarded by is coming from their sun, & life could evolve on the opposite side, having warmth, & maybe photosynthesis at the daylight-horizon?
Swift caught a red-dwarf emitting a flare 10k times more powreful than any we know about having been ejected by our Sun … but we’re looking at zillions of stars with our satellites, whereas we’ve only got a few decades of satellites watching our sun: there’s a measurement-disparity there, that is significant.
universe has surprised ALL of our assumptions about it, through the millenia… & the ONE rule on Earth for where life is, is: IF life CAN exist in some niche, THEN it does. Period.
Stratospheric bacteria with error-correcting-code DNA ( 4 compartments, each with about 1/3rd of the DNA, so it corrects radiation-induced-damage before dividing into daughter-cells, sorry I can’t remember where I read that, it was a couple decades ago ), bacteria eating bedrock, down where it’s too hot for anything else to live, etc…
To presume, as we normally do, that universe’s rules for life are different on Earth than everywhere-else, is … neither evidence-based nor correct-reasoning-based.
Therefore, betting that no red-dwarf-orbiting planet has any life on it … isn’t a bet I’d do.
That most such might be lifeless, I’ve no problem with that.
But any time we assert that “there’s no life” in an entire-category of universe’s places … that’s just prejudice, from what I can see.
There is some, indirect evidence that microbes used to live on Mars ( chemistry that has no other obvious explanation, e.g. )…
& that would indicate that life’s actually a normal-default, but that we evolved too-late to encounter Mars’s life…
Oh, & the flaring thing: being closer to a star makes flaring much more dangerous than it is to us: the energy-density at double the distance ( of the flare, between its sun & its planet ) would be 1/4, right? ( distance-squared ),
so closer would be massively more likely to be clobbered…
but … universe consistently surprises our assumptions, so I’m still holding-to the suspend-judgement, only speak for the majority, not for all, position.
_ /\ _
bedwyr@piefed.ca 10 hours ago
We should not presume either that all life is the same as life on earth. There are combinations of a great many different elements and molecules that could sustain life other than carbon and water and whatever. There could even be life on super hot places.
Of entirely different elements and molecules. Not saying it’s likely. I have no idea. Nobody does. And anybody that says they do, is either lying or wrong.
cynar@lemmy.world 8 hours ago
What combinations are you thinking of?
Life on earth is based around Carbon chains. Carbon’s 4 bonds allows for a low of complex structures that would be hard/impossible for less bonds.
The only other viable option I know of is silicon. Unfortunately its chain equivalent has an extra reaction pathway with water. It would degrade rapidly if exposed to water, which is very common at the energies it would work at.
I’d be curious to look up any other viable options.
nomy@lemmy.zip 6 hours ago
Your comment made me go down a pretty fascinating rabbit hole, hypothetical types of biochemistry. You mentioned silicon, with something like ammonia or methane serving the role of water. Carl Sagan apparently considered Silicon and Germanium possible substitutes for carbon
The article also mentions non-green photosynthesis and that other colored plants could support photosynthesis and might even be preferred in places that receive a different mix of solar radiation than Earth. Science so is fucking cool.
wonderingwanderer@sopuli.xyz 5 hours ago
Now that’s cool to think about. What if there’s a large ring of life around the daylight horizon that hosts complex organisms (would plant-like organisms have red chlorophyll?), and to the sun-facing side everything becomes a constant, immense blare of red light, x-rays, and UV radiation; and to the dark side is constant darkness broken only by the stars, and maybe some fungal/bacterial lifeforms and stuff that can feed on them.
What color would the horizon be? Like the “sunset” of a red dwarf, would it shift to blues and greens and purples or just be invisible?
macaw_dean_settle@lemmy.world 6 hours ago
*a lot.