Say that sometime in the future we’re able to terraform Mars and colonize it. OK, now, when in the distant future, some umpteen million or billion years from now, I forget which, when the sun…what’s it supposed to do, go nova? Super nova? Red giant?..anyway, whenever it grows very large and destroys the Earth, will the Mars collony be safe, or will they also be toast (pun intended)?
Mars will be toast too.
As for the future of the sun, I think that it will expand and become red giant, shrink again, expand, shrink and after awhile finally collapse into a brown dwarf.
So I guess if the human race wanted to survive, it would have to colonize outside of this galaxy?
Also, how long would it take the sun to become a red giant? Is it something that’s gradually happening or would it come somewhat suddenly? Years ago when I use to read science books, I remember something about stars expanding after they deplete…either their hydrogen or helium (it’s been a long time since I studied this).
Anyway, once depleted, how long would it take for the sun to start expanding?
By the time the Sun goes nova, if we’re still here and a spacefaring race, we should be well equipped to get our arses out of here. And we’d need to leave the solar system, not the Galaxy. I’m not sure that intergalactic travel will ever be possible in the lifetime of our species… but then I could be wrong.
As I understand it, the lifespan of a yellow star should be around 10 billion years, and Sol is around 5 billion, so we have plenty of time for R & D.
The Sun will expand into a red giant, blow off its outer layers (which will form a planetary nebula) leaving behind a white dwarf. (A brown dwarf is a “failed” star which is not massive enough to fuse hydrogen in its core.)
It’s debated whether the Earth will be engulfed when the Sun bloats up. Mars probably wouldn’t be absorbed, but it’ll be awful hot.
You want to move out to, say, the satellites of Saturn.
And work on developing a really efficient heat source.
Oops, I was using galaxy as a synonym for solar system, but upon thinking about it, that’s not correct. My mistake.
Actually we may not have another five billion years. Sol, like all mainstream stars, is slowly getting hotter as it progresses. Comparitively soon - 100 million years or less - it may no longer be possible for Earth to avoid a runaway greenhouse effect that will boil off the oceans in a (geologically) short period of time. But by that time we will either be extinct or able to do something about it.
Yes, well, I wrote a letter.
Oh, I think we could move out of our solar system rather soon, if we really tried. I mean, look at the technology in the 1920’s style death ray. And that was 80 years ago.