Nov. 27, 2001: NASA announces an exoplanet atmosphere

On Nov. 27, 2001, NASA announced the first detection of an exoplanet atmosphere. Using the Hubble Space Telescope’s spectrometer, astronomers observed HD 209458b, orbiting a 7th-magnitude, Sun-like star 150 light-years away in Pegasus. The researchers were able to detect sodium in the exoplanet’s atmosphere – though it was less sodium […]