By way of Slashdot comes a BBC article in which scientists explain how we will need to alter the Earth’s orbit to compensate for the ever-increasing brightness of our pre-death throw Sol. Otherwise, we will become a run-away greenhouse like Venus, followed by an arid, broiling rock like Mercury. This will be accomplished by using the energy from a rather large, passing asteroid, slingshotting us into a larger orbital path (a la deep-space satellites cruising around the planets to pick up speed).
Never mind that we will be extinct when this actually becomes a day to day problem (plus one billion years from now); but, if we’re not, They seem to have all the salient details already worked out:
If the 100 km asteroid was to collide with the Earth then it would wipe out all life on our planet. “This danger cannot be overemphasised,” the researchers stress.