Earth Doomed to Fiery End, Experts Predict


By Darren Osborne

February 23, 2008 01:00am
Article from: The Daily Telegraph

OUR planet faces a fiery doom inside the sun unless future generations work out how to change its orbit.

New calculations by University of Sussex astronomers predict the Earth will be burnt to a cinder then swallowed up by the sun in about 7.6 billion years.

Emeritus reader in astronomy Professor Robert Smith and his team thought they calculated that we may escape destruction but new figures take into account the effect of drag caused by the sun's outer atmosphere.

"We showed previously that, as the sun expanded, it would lose mass in the form of a strong wind, much more powerful than the current solar wind," Professor Smith said.

"This would reduce the gravitational pull of the sun on the Earth, allowing the Earth's orbit to move outwards, ahead of the expanding sun.

"However, the tenuous outer atmosphere of the sun extends a long way beyond its visible surface, and it turns out the Earth would be orbiting within these very low density outer layers."

He said the drag caused by the low-density gas would be enough to cause the planet to drift inward to be consumed by the sun.

However, if Earth remains in its current orbit, life isn't likely to be here in 7.6 billion years.

As the sun expands in its end sequence, Earth's surface temperatures will rapidly rise causing oceans to evaporate, leaving a hot, dry and uninhabitable ball.

Professor Smith suggested future generations may extend the planet's life by using the gravitational effect of a close passing asteroid to "nudge" our orbit away from the encroaching sun.

"It seems the energy requirements are just about possible and the technology could be developed over the next few centuries," he said.

Such a solution doesn't come without risk. Miscalculate, and the asteroid may hit Earth.

"A safer solution may be to build a fleet of interplanetary 'life rafts' that could manoeuvre themselves always out of reach of the sun, but close enough to use its energy," he said.