"Andrew Gray" wrote in message
. ..
http://www.wikipedia.org/wiki/Stellar_evolution
http://btc.montana.edu/ceres/html/starsbackground.htm
http://map.gsfc.nasa.gov/m_uni/uni_101stars.html gives a decent
explanation of stellar evolution - the gist is that, in a few billion
years, under current theories, the sun will extend to somewhere around
Jupiter. Probably a good idea to have moved out the neigbourhood by
then, if we're still around...

Shave that number down to "a couple of hundred million", actually. Earth
will be uninhabitable long before it's swallowed up inside the sun itself. I
read this in an article in Astronomy magazine, I think... I'll see what I
can dig up.

In any case, the sooner we get off this rock, the better.