An Iowa State University astronomer says the expanding red giant phase of our sun will “push” the moon closer to Earth, where it will eventually break up under the influence of our planet’s gravity and form a Saturn-like ring. The ring would be a temporary phase before those fragments begin dropping on the dessicated surface of a future dead Earth. Sort of sounds like the Bush presidency.
Lee Anne Willson tells us:
The Moon’s actual path is a wiggly line around the sun, with it moving faster when it is slightly farther out (at full moon) and more slowly when it is slightly closer (at new moon). So the gas drag is more effective at the farther part of the orbit and this will put the Moon into an orbit where the new moon is closer to Earth than the full moon.
There are other possible scenarios, but the major determining factor is how much of the sun is blown away when all the hydrogen has been fused into helium. If the sun loses little mass, then eventually the Earth will burn to a crisp as the sun expands into its red giant phase at about 5000000000 CE. If the sun burps out a significant portion of itself (as in the Helix Nebula over there) then the sun’s gravity, weakened enough, may push the earth out to a relatively safer distance.
Safety is relative, unfortunately. Before the moon gets crushed, our oceans will have already turned to steam and burned off, leaving a lifeless planet behind.