Sun will swallow Earth: Official

Two scientists from the University of Sussex and Mexico's University of Guanajuato appear to have confirmed that if we're still around in 7.6 billion years, global warming will be the least of our worries, since our beloved Mother Earth will be drawn inexorably towards the Sun and snuffed from existence.

Sussex Uni's Robert Smith and Guanajuato's Klaus-Peter Schroeder got out their calculators to determine once and for all whether Earth would escape a blazing death by spinning into a more distant orbit around the Sun, or whether it's ultimately curtains.

The former theory suggests that, as the Sun expands into a red giant, it will eject its outer gaseous layers, thereby losing mass and weakening its gravitational grip on the Blue Marble.

However, this get-out clause doesn't factor in tidal forces or the drag of the Sun's outer layer, according to the doomsday boffins. The Earth actually exerts its own (modest) gravitational pull on the Sun, causing the face closest to us to bulge out - an extrusion which constitutes bad long-term news.

Smith explained to Space.com: "Just as the Earth is pulling on the Sun's bulge, it's pulling on the Earth, and that causes the Earth to slow in its orbit. It will spiral back and finally end up inside the Sun."

In addition to this fatal attraction, the gaseous layers escaping from the Sun will exacerbate the problem, creating drag on Earth's orbit, further slowing it. The Register