How the exoplanet Kepler 10b fits in: NASA calls it the "first unquestionably rocky planet" - take that, CoRot-7b! - and also the smallest (diameter-wise) detected today. 1.4 Earth diameters, 4.6 Earth masses, orbiting a star like the Sun but 8 Gyr old.

How the exoplanet Kepler 10b fits in: NASA calls it the "first unquestionably rocky planet" - take that, CoRot-7b! - and also the smallest (diameter-wise) detected today. 1.4 Earth diameters, 4.6 Earth masses, orbiting a star like the Sun but 8 Gyr old.