LHS 3844 b shows dark, space-weathered surface without volcanic gases
Updated
Updated · Nature.com · May 4
LHS 3844 b shows dark, space-weathered surface without volcanic gases
10 articles · Updated · Nature.com · May 4
Using JWST’s 5-12 micrometre thermal emission spectrum, researchers found the rocky exoplanet’s surface best matches basalt or other olivine-rich, low-silica material.
The data rule out fresh fine-grained powdery surfaces and place upper limits on gases, disfavouring CO2 above 100 mbar and SO2 above 10 microbar.
The findings suggest an old, airless world shaped by space weathering, highlighting JWST’s growing ability to probe the geology and atmospheric history of rocky exoplanets directly.
JWST unveiled a barren super-Earth. Which distant rocky world will be the next to have its geological secrets revealed by the telescope?
With its atmosphere gone, what secrets does this planet's ancient, naked surface hold about the violent history of rocky worlds?
This super-Earth is a barren rock. What does this reveal about life's prospects on planets orbiting the galaxy's most common stars?
JWST Reveals LHS 3844 b as a Hot, Airless Basalt World with No Geological Activity
Overview
In 2026, the James Webb Space Telescope revealed that the exoplanet LHS 3844 b is a dark, airless world with a surface of basalt rock, similar to the Moon's maria. Tidally locked to its red dwarf star, it has a scorching dayside around 725°C and a cold nightside, causing its atmosphere to be stripped away. Its short, circular orbit prevents internal heating, halting geological activity. Without an atmosphere, space weathering by radiation and micrometeorites darkens the surface and creates a feedback loop that keeps the planet geologically dead and uninhabitable. This discovery launches exogeology, offering a unique glimpse into the ancient, stagnant surfaces of rocky worlds around red dwarfs.