British researchers have found that the sun will, in time, emit enough heat to cause the Earth’s oceans to evaporate – rendering the planet uninhabitable.
It is what some are describing as the ‘inconvenient consequence’ of the Earth’s orbit and the natural life cycle of the sun.
“It will get progressively hotter and there’s nothing we can do about it,” Andrew Rushby, from the University of East Anglia, told reporters.
Rushby’s work centres on measuring planet habitability. Detecting the surface heat of a planet and determining whether water is available can help to determine a planet’s habitable zone. But that is only a very basic measure of a planet’s overall capacity to sustain life comfortably.
The study’s findings, published in the journal Astrobiology, revealed that the sun’s habitable zone was growing one tenth of an astronomical unit every billion years – which also happens to be the distance from Earth to the sun.
While the earth still has roughly one and a half to three billion years before the sun’s heat renders it uninhabitable, humans may not still be around until the very end.
“If we are still around, and the optimist in me likes to think we would be, I hope we’d be away from the Earth, perhaps on Mars, or spread out in a huge galactic family across the Milky Way,” Rushby said, forecasting that humans may have evolved quite a bit by then.
Astronomers argue they have spotted at least 1,000 planets beyond our current solar system and using the habitability model they feel confident they will be able to predict which of the planets will have the potential to sustain life.
“The models can help us identify planets with similar habitable lifetimes to Earth and we want to pass these on to other astronomers and astrobiologists. These planets have been around and habitable for around the same amount of time as we have, so they become more promising candidates. There’s no point looking for intelligent life on a planet that has not been habitable for very long,” Rushby explained.
Only 600 light years away is the planet Kepler 22b in the constellation Cygnus. Having a predicted habitable time that is slightly longer than Earth makes it an ideal candidate says Rusbhy.
If all else fails, Mars may be out next best chance. It will remain habitable until the sun dies in six billion years – the only catch is “it doesn’t have much atmosphere”.