QUOTE
Sun will swallow earth: astronomers
Saturday Feb 23 11:46 AEDT
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 that the earth will not only be burnt to a cinder, but will also be swallowed up by the sun in about 7.6 billion years.
Emeritus reader in astronomy Professor Robert Smith and his team had previously calculated that the earth might escape ultimate destruction.
However, new calculations now take into account the effect of drag caused by the outer atmosphere of the dying sun.
"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," Prof 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 actually be orbiting within these very low density outer layers."
According to Prof Smith, the drag caused by the low-density gas would be enough to cause the earth to drift inwards, and finally to be swallowed by the sun.
However, if the earth remains in its current orbit, life isn't likely to be around in 7.6 billion years time.
As the sun expands during the end of its life, temperature on the earth's surface will rapidly rise causing oceans to evaporate, leaving a hot, dry and uninhabitable ball.
Prof Smith suggests future generations could extend the life of the planet by using the gravitational effect of a close passing asteroid to "nudge" our orbit away from the encroaching sun.
"This sounds like science fiction," Prof Smith said.
"But it seems that the energy requirements are just about possible and the technology could be developed over the next few centuries."
Such a solution doesn't come without risk. A slight miscalculation, and the asteroid could actually hit the earth, with catastrophic consequences.
"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.
Saturday Feb 23 11:46 AEDT
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 that the earth will not only be burnt to a cinder, but will also be swallowed up by the sun in about 7.6 billion years.
Emeritus reader in astronomy Professor Robert Smith and his team had previously calculated that the earth might escape ultimate destruction.
However, new calculations now take into account the effect of drag caused by the outer atmosphere of the dying sun.
"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," Prof 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 actually be orbiting within these very low density outer layers."
According to Prof Smith, the drag caused by the low-density gas would be enough to cause the earth to drift inwards, and finally to be swallowed by the sun.
However, if the earth remains in its current orbit, life isn't likely to be around in 7.6 billion years time.
As the sun expands during the end of its life, temperature on the earth's surface will rapidly rise causing oceans to evaporate, leaving a hot, dry and uninhabitable ball.
Prof Smith suggests future generations could extend the life of the planet by using the gravitational effect of a close passing asteroid to "nudge" our orbit away from the encroaching sun.
"This sounds like science fiction," Prof Smith said.
"But it seems that the energy requirements are just about possible and the technology could be developed over the next few centuries."
Such a solution doesn't come without risk. A slight miscalculation, and the asteroid could actually hit the earth, with catastrophic consequences.
"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.
Could they be any more dramatic! Sheesh!
