Sizing Up ExoplanetsAstronomers using data from NASA Kepler mission and ground-based telescopes recently discovered the three smallest exoplanets known to circle another star, called KOI-961.01, KOI-961.02 and KOI-961.03. Download ShareTakenJanuary 11, 2012ProducerJPLSize1920x853pxPIA NumberPIA15258