Published April 17, 2014 at 520 × 292 in NASA’s Kepler Telescope Discovers First Earth-Size Planet in ‘Habitable Zone’ The diagram compares the planets of our inner solar system to Kepler-186, a five-planet star system about 500 light-years from Earth in the constellation Cygnus. Image credit: NASA Ames/SETI Institute/JPL-Caltech (Visited 9 times, 1 visits today)