From 0 to 5,000 Planets in Exactly 20 Years
Twenty years ago today, an invisible object circling an obscure star in the constellation Pegasus overturned everything astronomers knew about planets around other stars. No, the fallout was even bigger than that. The indirect detection of 51 Pegasi b—the first planet ever found around a star similar to the sun—revealed that they had never really known anything to begin with.