NASA has identified a planet 600 light years away that might be habitable by humans. Kepler 22-b is 2.4 times the size of our planet and lies in the ‘Goldilocks zone’ that has been marked out as the most likely location for planets hospitable to human life.
The planet has a surface temperature of about 22C (72F) and is believed to possess both water and land. However, its exact composition is not yet known, and it could turn out to be made mainly of gas, in which case it would be impossible for humans to live there. Its extreme distance from us is also something of a problem.
Other promising life-supporting planets have been identified in the past, but Kepler 22-b is by far the most viable candidate to date. The planet is one of more than 700 exoplanets identified in recent years, with thousands more waiting to be confirmed. A newly-launched Habitable Exoplanets Catalogue lists exoplanets and defines their potential for supporting life.