Discovery of Earth's Twin 'Within Reach'

The Kepler spacecraft prowling the far reaches of the Milky Way will soon find a habitable planet similar to earth, a leading astronomer is convinced. Recent technological advances in the observation of planets outside our own solar system have rapidly brought us closer to finding earth's "twin" planet, says Michel Mayor, the scientist who discovered the first extrasolar planet in 1995.

"The search for twins of Earth is motivated by the ultimate prospect of finding sites with favorable conditions for the development of life. We’ve entered a new phase in this search,” Mayor said. A planet has to meet tough criteria to be fit for human habitation, the Telegraph reports: Most exoplanets are much larger than earth, meaning very active tectonic plates create a turbulent environment, and most are either too hot or too cold to have water. Mayor expects planet will be found with the winning combination within four years. (More Kepler spacecraft stories.)