NASA Survey Suggests Earth-Sized Planets Are Common

"Nearly one in four stars similar to the sun may host planets as small as Earth, according to a new study funded by NASA and the University of California. The study is the most extensive and sensitive planetary census of its kind. Astronomers used the W.M. Keck Observatory in Hawaii for five years to search 166 sun-like stars near our solar system for planets of various sizes, ranging from three to 1,000 times the mass of Earth. All of the planets in the study orbit close to their stars. The results show more small planets than large ones, indicating small planets are more prevalent in our Milky Way galaxy."