20 years ago astronomers discovered the first planet outside our solar system

Photo credits: NASA/JPL-Caltech

New Delhi: Recently on October 6th 2015, NASA celebrated the 20th anniversary of the first planet found orbiting a Sun-like star, 51 Pegasi b.

51 Pegasi b was the first planet spotted around a “normal” star like our Sun. The size of the planet is half the mass of Jupiter but it orbits closer to its star than Mercury does to our Sun, a prototype for so-called hot Jupiters.

The planet was then discovered by astronomers Michel Mayer and Didier Queloz and announced on October 6, 1995. They found it by using the radial velocity method that detects the gravitational influence of a planet on its star.

Meanwhile, using NASA’s hugely successful Kepler space telescope, thousands of exoplanets have now been found.