My Question is about the fascination in looking for life on M class or Red Dwarf stars.

We all know that Most stars (70%) are M Class, so looking at those stars is going to be important. The "Habitable" zone around a Red Dwarf is very close to the star, and Red Dwarfs are still very active in terms of solar flares. Being that close the star and getting caught in a solar event seems like it would be more of a rule than just an accident.

We live on a world with a fairly stable sun and a robust Magnetosphere, and are far enough away that the damage can be mitigated, but still we have had some issues with it. When you are that close to an active sun, it seems to me, that any life that might have made a foothold would be killed off anytime the sun had a bad day. Even if you were lucky enough to not have your atmosphere be blown off, the radiation would destroy any life that might have started.

It's entirely possible that I am missing some major idea or explanation. In fact I hope that I am. I understand that we want it to be a possibility since most of the galaxy is M Class stars and that making them viable is preferable, but I could never get my mind around it. Is it just wishful thinking or am I missing something huge?

It's a serious question, and I hope you will take it as such. Is looking for life on an M Class star just wishful thinking, because it makes the chances of finding life out there so much less daunting?

  • 4
    $\begingroup$ Nobody knows. Sorry but this answer is the same for almost every question about extraterrestrial life. Nobody knows what it is like. Speculation is fun, but that's all it is. $\endgroup$
    – James K
    Commented Aug 9, 2023 at 18:51
  • $\begingroup$ Proxima Centauri b is a potentially habitable exoplanet, and its parent star Proxima Centauri is a red dwarf. $\endgroup$ Commented Aug 10, 2023 at 0:02
  • $\begingroup$ "...life on M class or Red Dwarf stars." Life on stars is pretty challenging, at least during the daytime. $\endgroup$
    – uhoh
    Commented Aug 19, 2023 at 4:01
  • $\begingroup$ related: Do M dwarf stars emit the wavelengths of the electromagnetic spectrum necessary for photosynthesis? $\endgroup$
    – uhoh
    Commented Aug 19, 2023 at 4:08

1 Answer 1


Check the ocean floor

If ionizing radiation is a concern, deep water is a very effective shield. It's theorized that life on Earth started around hydrothermal vents in the dark depths of the ocean, far from the powerful ultraviolet light ("the sun is a deadly lazer") that made the surface uninhabitable until we got enough oxygen to form an ozone layer.

You could similarly find protection from ionizing radiation far underground, but (my opinion) deep ocean is a more likely place to find life as we know it on a high-radiation world.

And that applies not only to red dwarf stars; there is very likely to be liquid water under the ice of the Jovian moons that could potentially protect life from the ionizing radiation that Jupiter throws out.

Life could evolve defenses

But if we're just theorizing wildly, it's possible the whole ecosystem would just evolve to handle radiation damage better than it did on Earth. There's at least one extremophile bacteria we know of that can survive hard vacuum and radiation really well (Deinococcus radiodurans), so maybe there's tricks that life could use to rebuild its DNA-equivalent after damage without picking up too many mutations.

Or, maybe life wouldn't leave the oceans, or even occupy the upper layers, until it develops metallic shells that keep off the worst of it.

Or just put up with it

Maybe any flare activity would be rare enough or short-lived enough that it just causes periodic die-offs that don't actually fry the whole surface, and the ecosystem would just evolve around that fact, the same way pyrophyte forests expect fires, and even take advantage of the aftermath.

It's really hard to make any scientific analysis of what could be possible on other worlds, because we have a data set of one to work from.

  • $\begingroup$ Would marine life eventually be able to get onto land (assuming there is any), once the star's calmed down in ~7gy? [![katjapoppenhaeger.com/?p=457][1]][1] [1]: i.imgur.com/PAYNRsD.png $\endgroup$
    – Kazon
    Commented Aug 9, 2023 at 17:50
  • $\begingroup$ Can hypothetical life on a hypothetical planet under a hypothetical star eventually move onto land? Hypothetically, sure. $\endgroup$ Commented Aug 9, 2023 at 18:30

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