In May of last year (<-- By frogs and fishes! That is fun/weird to type), Yinon M. Bar-On, Rob Phillips, and Ron Milo published a report in the Proceedings of the National Academy of Sciences of the United States of America
on a census of all life on Earth, by surveying and estimating how much carbon is where, on the planet, by weight
Vox.com published a stunning visual chart of what this all means, )here
That's cool, and wondrous, and exciting (and sobering), and all...But then
-- in December, The Deep Carbon Observatory published its own report on a survey of carbon deep within the Earth's crust
-- and came to the conclusion that all the bacterial biomass carbon from that earlier report? Is only 30% of the total bacteria on Earth
.... And there are bacteria surviving so close to the Earth's core that ambient temperatures are above 100 C
-- but water is still liquid, there, because the pressure is so high.
Okay, so 70-80% of stars in our galaxy are M dwarf stars, which are rather violent when young, and this video (closed captioned) explains why that might end up making the planets ultimately uninhabitable.
But M dwarf stars are extremely long-lived, and once their violent youth is past, they become very stable (I'll put a video about the life cycle of stars at the end of this post).
And if the majority of microbial life actually starts out
deep beneath the surface of planets, then (my inner plot bunnies are whispering) perhaps it could survive its home star's violence, and gradually migrate to the surface once it's calmed down ... And, as I always like to remind myself, life has a way to change a planet to make it more comfortable to life.
Or maybe they won't migrate to the surface, but they still might form comparatively complex life. Here's a neat video from Kurzgesagt (also closed captioned) that explores the possibility of subsurface life that exists on planets that don't even have
(The main thing that annoys me about Kurzgesagt videos, is that they keep judging quality of life and intelligence by current, human
normativity: use of metal-based technology, fire, etc.. Also, they assume that advancement as a civilization must depend on expanding our territory, and colonizing other worlds, and also in getting as close to individual immortality as possible. ... none of which are things I agree should be taken as givens)
Anyway, here's that video on the life cycle of low-mass stars, and there's a suggestion how the Earth, itself, might become a rogue planet, 6 billion years or so, from now, when our Sun burns through its hydrogen and loses mass -- which decreases the gravity that holds planets in their orbits (also closed captioned):
(For what it's worth: I'm not really all disturbed by the thought of humanity going extinct, or even of my own personal death, as long as neither comes prematurely, due to foolish decisions -- like denying climate change -- or causes avoidable pain to others)