Double star could host habitable planet

Planets with two suns – like Star Wars’ Tatooine – could really be habitable, astrophysicists have concluded – and they say they know where to look.

Back in September, researchers using NASA’s Kepler space telescope discovered Kepler-16b, a cold, gaseous planet orbiting two stars around 200 light years from Earth.

Now, a team from the University of Texas at Arlington has found that if Kepler-16b has a moon, it could be capable of supporting life. Based on the brighter of the two stars’ heat output, they established that there should be a habitable zone between about 34 million and 66 million miles out.

Kepler-16b lies towards the outside edge of this zone; and while it’s uninhabitable itself, a rocky moon – which would have anough gravity to retain an atmosphere – could be a different matter.

The team also believes an ‘extended habitable zone’ exists outside the orbit of the gaseous planet – for a planet with high levels of greenhouse gases such as carbon monoxide or methane in its atmosphere.

Previous research has indicated that life could be found outside the traditional habitable zone of a star, but only if chemicals in the atmosphere create a strong back-warming effect.

“This is an assessment of the possibilities,” says physics professor Zdzislaw Musielak.

“We’re telling them where a planet has to be in the system to be habitable. We’re hoping they will look there.”