Illustration of WASP-39b, an exoplanet which lies about 700 light-years away from Earth, orbiting its host star from just 0.0486 astronomical units away. Due to WASP-39b being very close to its host star, it is very hot and is thought to be tidally locked. The James Webb Space Telescope's (JWST) Near-Infrared Spectrograph (NIRSpec) has detected carbon dioxide in the atmosphere of WASP-39b. Other observations collected by Hubble Space Telescope and Spitzer Space Telescope indicate the presence of water vapour, sodium and potassium.