TRAPPIST-1 d (artist impression)

This artist’s concept depicts planet TRAPPIST-1 d passing in front of its turbulent star, with other members of the closely packed system shown in the background.

The TRAPPIST-1 system is intriguing to scientists for a few reasons. Not only does the system have seven Earth-sized rocky worlds, but its star is a red dwarf, the most common type of star in the Milky Way galaxy. If an Earth-sized world can maintain an atmosphere here, and thus have the potential for liquid surface water, the chance of finding similar worlds throughout the galaxy is much higher. In studying the TRAPPIST-1 planets, scientists are determining the best methods for separating starlight from potential atmospheric signatures in data from the NASA/ESA/CSA James Webb Space Telescope. The star TRAPPIST-1’s variability, with frequent flares, provides a challenging testing ground for these methods.

[Image description: Illustration of a planet silhouetted in front of a star. The star shows a large eruption on one side and more wisps of red coming from its southern hemisphere. Two more planets appear in the background.]