Board Thread:Off-topic/@comment-26462356-20160826052936/@comment-26462356-20160826215349

MiniDaggers wrote: So this is closer than the Kepler one correct?

Why wasn't it noticed until now? All the Kepler stars are dozens, if not hundreds, of light years away. The Kepler method depended on constantly watching thousands of stars for planets to pass in front of them. The best way to do this was to look at a patch of sky were there were a large number of suitable stars, the best place to look happened to have most of the stars being relatively far away.

The method used to observe Proxima Centauri was quite different. It involved watching just the one star for any wobbly movement by the star. Once they collected enough observations they could then calculate if the wobble was caused by the gravity of a planet pulling on it, and how large the planet was and how far away it was. It took 16 years to collect enough observations.