Astronomers have detected a hydroxyl radical (OH) — the neutral form of the hydroxide ion — in the dayside atmosphere of the ultrahot Jupiter exoplanet WASP-33b. It is the first time that OH has been detected in the planetary atmosphere outside the Solar System. An artist’s impression of the ultrahot Jupiter WASP-33b and its parent star. Image credit: Astrobiology Center. Discovered in 2010, WASP-33b is a gas giant approximately 4.5...
