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If it makes you feel any better, it looks like that in 7 billion years the Sun actually *will* swallow the Earth. https://www.syfy.com/syfywire/so-um-maybe-the-sun-will-eventually-swallow-the-earth-bummer">https://www.syfy.com/syfywire/...
2/ There& #39;s been some back and forth about this over the years. As the Sun uses up its stock of hydrogen to fuse, it& #39;ll start to blow a much denser solar wind. That means it loses mass, and its gravity weakens. The orbits of the planets will expand in response.
3/ It will also expand into a red giant. These kinds of stars are very, very big. Very. When the Sun gets all swole it& #39;ll be *100 - 200* times bigger than it is now. Possibly up to 350X.
4/ The question is, will the Earth move away from the Sun faster than the Sun& #39;s surface expands? IOW will the Earth get swallowed up by the red giantification of the Sun or will it be able to escape that fate?
5/ Turns out the amount of mass lost by a star depends on a few things, including whether it has a close-in giant planet. If we replaced Mercury with Jupiter, then, when the Sun expanded and swallowed Jupiter, the planet would make the Sun spin faster. Mass loss would increase.
6/ That would make Earth recede faster and it would be saved. Hurray! Except there IS no close-in Jupiter. The Sun won& #39;t lose as much mass as once thought, so Earth won& #39;t recede as fast, and the Sun& #39;s expansion *will* swallow it. Boo? Yay? YKMV*.
*Your kilometerage may vary.
*Your kilometerage may vary.
7/ Not that it really matters. Even if the Earth doesn& #39;t wind up physically inside the Sun, having a blazing red giant occupying half the sky isn& #39;t good for the climate. Earth& #39;s surface will be totally molten. Hopefully by then we& #39;ll have found a second home around another star.
8/ If you want details of all this I have a fairly graphic description and timeline (including a way to move the Earth out from the Sun and buy us a few hundred million years) in my book "Death from the Skies!". https://amzn.to/2OLegfF ">https://amzn.to/2OLegfF&q...
9/9 Personally, 7 billion years is long enough that my go-bag is set for more immediate concerns. But learning how stars behave is important. We orbit one, and depend on it critically in every way. Understanding it seems like a good idea to me. https://www.syfy.com/syfywire/so-um-maybe-the-sun-will-eventually-swallow-the-earth-bummer">https://www.syfy.com/syfywire/...
