Wednesday, February 26, 2014

Kepler bags huge haul of planets

The science team sifting data from Nasa's Kepler space telescope says it has identified 715 new planets beyond our Solar System.


This is a huge new haul.


In the nearly two decades since the first so-called exoplanet was first discovered, researchers had claimed the detection of just over 1,000 new worlds.


Kepler's latest bounty orbit only 305 stars, meaning many are in multi-planet systems.


The vast majority, 95%, are smaller than our Neptune, which is four times the size of the Earth.


Four of the new planets are less than 2.5 times the size of Earth, and they orbit their host suns in the 'habitable zone' - the region around a star where water can keep a liquid state.


Whether that is the case on these planets cannot be known for sure - Kepler's target are hundreds of light-years in the distance. This is too far away for very detailed investigation.


Kepler was launched in 2009 on a $600m (£395m) mission to assess the likely population of Earth-sized planets in our Milky Way Galaxy.


Faulty pointing mechanisms eventually blunted its abilities last year, but not before it had identified thousands of possible, or candidate, worlds in a small patch of sky in the Constellation Lyra.


It did this by detecting the periodic variations in the brightness of stars caused by orbiting exoplanets passing in front of them.


One analysis of Kepler data published in November suggested that perhaps one in five stars like our Sun hosts an Earth-sized world located in the habitable zone.



Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos