A planet that is about the size of Saturn, but with a temperature more like Earth’s, has an atmosphere rich in methane, according to a new study using NASA’s James Webb Space Telescope (JWST).

Unlike the gas giant planets—Jupiter and Saturn—in Earth’s solar system, which are distant from the sun and therefore extremely cold, and so-called “hot Jupiters”—giant planets beyond the solar system that are scorching hot due to their proximity to the stars they orbit—the planet is one of only a handful of known temperate, giant planets and the first to have its atmosphere analyzed.

The new details about the composition of the planet’s atmosphere will inform models of planetary formation and evolution and could improve astronomers’ understanding of how Earth’s atmosphere works, according to the research team.