James Webb Telescope Finds LHS 3844 b Is a Barren, Airless World With Volcanic Rock Surface

Astronomers have obtained the clearest look yet at the surface of exoplanet LHS 3844 b using NASA’s James Webb Space Telescope. The rocky world, located about 49 light-years from Earth, has a diameter about 30% larger than Earth and orbits a red dwarf star smaller and less luminous than the sun. The study detailing the findings was published this week in the journal Nature Astronomy.

The planet, also called Kua’kua after the word for butterfly in an indigenous language spoken in Costa Rica, orbits its star once every 11 hours. It is tidally locked, with one side always facing the star and the other side always facing away. The dayside surface temperature reaches about 1,340 degrees Fahrenheit (725 degrees Celsius), while there was no detectable heat on the nightside.

Webb, which was launched in 2021 and became operational in 2022, detected infrared light coming directly from the surface of LHS 3844 b. 3% that of the sun. 5 trillion km).

Dark volcanic rocks like basalt matched the observations of LHS 3844 b’s surface much better than brighter, silica-rich rocks like granite, Sebastian Zieba said. Zieba, an astronomer at the Center for Astrophysics, Harvard & Smithsonian in Massachusetts, is lead author of the study. The surfaces of Mercury and the moon are basalt-dominated.

“Different rocks have different spectral fingerprints, just like atmospheres do. On Earth, widespread granite formation is linked to water and plate tectonics.

So if you ever robustly identified granite-like surfaces on an exoplanet, that would not (automatically) mean life, but it would suggest a much more Earth-like geological history compared to other surfaces, he added. Researchers searched for volcanism-related gases like sulphur dioxide on LHS 3844 b and found none.