Science Blog ZINC PROJECTS

Future Sun could vaporize Earth

Date: 26-Feb-08
Author: University of Sussex

New calculations by University of Sussex astronomers predict that the Earth will be swallowed up by the Sun in about 7.6 billion years unless the Earth's orbit can be altered.

Previous calculations suggested that the Earth would escape ultimate destruction, although be battered and burnt to a cinder. But this did not take into account the effect of the drag caused by the outer atmosphere of the dying Sun.

Life on Earth will have disappeared long before 7.6 billion years, however. Scientists have shown that the Sun's slow expansion will cause the temperature at the surface of the Earth to rise. Oceans will evaporate, and the atmosphere will become laden with water vapour, which (like carbon dioxide) is a very effective greenhouse gas. Eventually, the oceans will boil dry and the water vapour will escape into space. In a billion years from now the Earth will be a very hot, dry and uninhabitable ball.


Artist's conception of the remains of artificial structures on the Earth after the Sun enters its red giant phase and swells to roughly 100 times its current size. Art created and donated to Wikipedia by B. Jacobs.

Can anything be done to prevent this fate? A team at Santa Cruz University suggested harnessing the gravitational effects of a close passage by a large asteroid to "nudge" the Earth's orbit gradually outwards away from the encroaching Sun.

Full story: The Sun will vaporise the Earth unless we can change our orbit