Phobos Impacting Mars

[Shatnertage]

I remember reading somewhere (maybe here) that we actually have a lot less than 5 billion years left before the sun expands or contracts enough to make Earth unlivable--like somewhere in the realm of 100 million years. Is this true?

 

[Christopher]

I remember reading somewhere (maybe here) that we actually have a lot less than 5 billion years left before the sun expands or contracts enough to make Earth unlivable--like somewhere in the realm of 100 million years. Is this true?

Yes and no. It's not a change in the Sun's size that's at issue, it's a change in its luminosity. Stars like the Sun get steadily hotter over their Main-Sequence lifetimes. To some extent, the Earth has a natural feedback mechanism to compensate for this: the hotter the planet gets, the more carbon dioxide is removed from the atmosphere (I don't recall exactly why), cancelling out the heating. But eventually the Sun would get hot enough that the feedback wouldn't be enough. This is estimated to be over a billion years in the future. It's possible that there's another regulating mechanism that could double that.

 

[ALF]

This solar system has hit rock bottom.
I'm packing my bags.

 

[Trekker4747]

I look forward to the White Dwarf stage. The sun isn't doing anything it's just there. A large, hot, rock in space. I want to stand next to it and try and keep my hands warm as it were a dying fire. A fire that'll take millions of years to burn out.

 

[All Seeing Eye]

Where will be a "comfort zone" when the sun swells? Jupiter? Saturn? Neptune?

I read that when is swells it will be as far out as Pluto. LINK

Before it swells though It's supposedly going to get hotter and hotter so IMO I think it's going to be Jupiter where it will be more hospitable temperature wise so I reckon the outer Moons of Jupiter might become more homely.

 

[SPCTRE]

Look, just read Kim Stanley Robinson's Mars trilogy. That'll tell you everything you could possibly want to know about the science and logistics of colonizing Mars.

Well, I guess I know now what I'll be reading right after I'm done with Zero Sum Game

 

[Jetfire]

Where will be a "comfort zone" when the sun swells? Jupiter? Saturn? Neptune?

I read that when is swells it will be as far out as Pluto. LINK

Before it swells though It's supposedly going to get hotter and hotter so IMO I think it's going to be Jupiter where it will be more hospitable temperature wise so I reckon the outer Moons of Jupiter might become more homely.

I was lookin' at setting up shop around Neptune or Uranus in the future.

 

[diankra]

Look, just read Kim Stanley Robinson's Mars trilogy. That'll tell you everything you could possibly want to know about the science and logistics of colonizing Mars.

Well, I guess I know now what I'll be reading right after I'm done with Zero Sum Game

Worth mentioning that, as Stephen Baxter (edit: actually, I think it was Alastair Reynolds) points out, the Mars trilogy crosses the line between hard-SF and artistic licence SF by contracting the terraforming timeframe into a span that suits his plot (and the extended longevity of his characters).
It is, otherwise, very hard, real science. About as solid as you can get.