The Mudcat Café TM
Thread #145209   Message #3358158
Posted By: Don Firth
01-Jun-12 - 05:29 PM
Thread Name: BS: When Worlds Collide...
Subject: RE: BS: When Worlds Collide...
Well, I dunno about that. The sun is a G spectral class main sequence star that has been around for about 4.5 billion years. It's also about 20% larger than most other main sequence stars of its kind, with a lot of fuel left. Best estimates are that could go at least another 5.5 billion years, and quite possibly as much as 10 billion.

By then, it will have consumed most of its hydrogen fuel and begun fusing helium and heavier elements into heavier elements still. As it does this, it will begin to collapse into its core, and its outer layers will bloat—out to near the orbit of Mars. This, of course, will be the end of the earth—and us, if we're still hanging around.

It will end by collapsing into a very dense white dwarf about the size of the earth, and it will last for many more billions of years before it fades into a cinder.

Don't need to make out "Change of Address" cards for a bit yet. . . .

Don Firth