In the past, astronomers had no evidence that there were planets orbiting other stars. Now, they estimate that the Milky Way might contain huge numbers of planets, with rocky, Earth-sized worlds outnumbering the rest.
Astronomers have been using gravitationa
An exoplanet will bend light as it passes in front of its parent star, causing a slight brightening of the star’s light. Microlensing has allowed astronomers to look at a lot more stars for exoplanets. Unlike other methods, microlensing can discover planets with different masses and distances from their star.
Sahu says that there are about one-sixth of stars that should have Jupiter-like planets, half have Neptune-sized planets, and two-thirds should have Earth-like planets.
[via Wired, images by Wikimedia and NASA Kepler mission]