Astronomers using the James Webb Space Telescope (JWST) discovered that the exoplanet HD 189733 b, located 64 light-years away, has an atmosphere rich in hydrogen sulfide, giving it a rotten-egg odor. This Jupiter-sized gas giant, known for extreme weather and high temperatures, offers new insights into exoplanetary atmospheres. The study, led by Guangwei Fu of Johns Hopkins University and published in Nature, involved researchers from Arizona State University. HD 189733 b, a well-studied hot Jupiter with a two-day orbit and 1,700°F temperatures, continues to intrigue scientists.