The fraction of sun-like stars having planets of different sizes, orbiting within one-fourth of the Earth-sun distance (0.25 AU) of the host star. Image credit: Erik Petigura, Geoff Marcy, Andrew Howard,
The fraction of sun-like stars having planets of different sizes, orbiting within one-fourth of the Earth-sun distance (0.25 AU) of the host star. The graph shows that planets as small as Earth (far left) are relatively common compared to planets 8.0 times the size of Earth (similar to Jupiter). For example, 7.9 percent of sun-like stars harbor a planet with a size of 1.0 to 1.4 times the size of Earth, orbiting inward of one-fourth the Earth-sun distance (closer than Mercury’s distance from the sun). There are increasing numbers of planets from 8 times the size of Earth down to 2.8 times Earth. Remarkably, the number of planets smaller than 2.8 times Earth is approximately constant with planet size, down to the size of our Earth. The gray indicates the planets discovered in this study, and the orange represents the correction applied to account for planets our software would miss statistically, typically about 20%. Image credit: Erik Petigura, Geoff Marcy, Andrew Howard,