Astronomers using NASA’s James Webb Space Telescope have studied the atmosphere of TOI-199b, a rare Saturn-sized planet with temperatures around 175 degrees Fahrenheit. The findings mark the first detailed look at a temperate giant exoplanet.
The planet orbits a star more than 330 light-years from Earth and completes one orbit every 100 days. Researchers detected methane in its atmosphere using transmission spectroscopy during a seven-hour transit observed over 20 hours total.