Earth’s twin found 42 light years from the Sun
Published 09/11/2012 | 10:13
A ‘super-Earth’ that could have a life-supporting climate has been discovered in a multi-world solar system 42 light years from the Sun.
The planet, which is several times more massive than the Earth, lies just the right distance from its star to allow the existence of liquid surface water.
It orbits within the star's habitable or ‘Goldilocks’ zone — where temperatures are neither too hot nor too cold to sustain life. The new world is one of six, all with masses a few times that of Earth, believed to circle the dwarf star HD 40307 in the constellation Pictor.
All the others are outside the habitable zone, too close to their parent star to support liquid water.
Three of these were originally identified in 2009 by European Southern Observatory astronomers. They used an instrument called Harps (High Accuracy Radial Velocity Planet Searcher) to look for changes in the colour of starlight that give away the presence of planets.
A new analysis of the Harps data, using special computer software, has now revealed three more super-Earths.
One, HD 40307g, excited astronomers because it was much further from the star than its companions and comfortably within the habitable zone.