Exoplanet Kepler 37b is small, how small you ask? Smaller than Mercury, that means we now have a reasonable chance to detect more Earth sized planets orbiting distant Suns. The parent star, Kepler 37 is located 210 light years and is a Sun like star about 80% of the mass and 97% as bright as our Sun. Kelpler 37b has a diameter of 2400 miles or 3800 km, and is more than likely a rocky little world similar to Mercury that takes 13.4 Earth days to orbit its Sun.
BBC News reports:
"I think it's an amazing technological achievement to be able to be able to detect small rocks like this," said Francois Fressin, a co-author of the paper based at the Harvard-Smithsonian Center for Astrophysics.
"It means we're really in the arena where it's possible to detect all the planets of our Solar System, but around other stars"