[BobaFloutist]

> How many years until the expanding sun's corona envelops the earth?

So, so, so many years. We've gotten as far as we have in something like 200,000 years, with most of our technological advancement happening in the last...I don't know, let's be generous and call it 10,000.

It takes probably what, two hundred years for technology to become nearly unrecognizably advanced these days?

We have around 7 and a half billion years before the sun wipes us out. Trying to get people on Mars with current technology has its arguments, but that we'll run out of time if we put it off anymore isn't one of them.