5-8 There are billions and billions of planets

Given the growing number of exoplanets that are being discovered orbiting a wide range of stars, astronomers are beginning to make estimates for the total number of planets in our Milky Way Galaxy and the number of those planets orbiting Sunlike stars. The results are impressive: On average, every five stars have, among them, eight planets. At least one in every six stars has an Earthlike planet orbiting it closer than Mercury is orbiting the Sun. Our Galaxy is believed to have more planets than stars, both of which run in the hundreds of billions. All of these numbers will be refined as better estimates are determined for the percentage of star systems with planets.