In 1995, astronomers found the first planet around a sun-like star that shouldn't exist

Michel Mayor and Didier Queloz detected 51 Pegasi b by tracking a tiny wobble in its star's light, revealing a gas giant half Jupiter's mass orbiting closer to its star than Mercury orbits the Sun. Nothing like it existed in our solar system, forcing astronomers to rethink how planets form and migrate. The find launched the modern exoplanet search and won the pair the 2019 Nobel Prize in Physics.

— Michel Mayor and Didier Queloz, 51 Pegasi b — Nature, 1995