Kepler-186f

Kepler-186f is seen in a NASA artist's concept released April 17, 2014.

Until We Get Better Tools, Excited Reports of ‘Habitable Planets’ Need to Come Back down to Earth

An artist's impression of Kepler-452b and its size compared to Earth. Credit: NASA/Ames/JPL-Caltech

NASA Finds Earth’s Bigger, Older Cousin