JWST Probes LHS 3844b Surface 50 Light-Years Away, Pointing to Basalt and No Plate Tectonics
Updated
Updated · ScienceAlert · May 26
JWST Probes LHS 3844b Surface 50 Light-Years Away, Pointing to Basalt and No Plate Tectonics
3 articles · Updated · ScienceAlert · May 26
MIRI spectra from JWST indicate LHS 3844b’s surface is dark and likely basaltic—closer to lunar rock or Earth’s mantle than to an Earth-like silicate crust.
The 30%-larger-than-Earth planet circles its red dwarf every 11 hours and reaches about 1,000 Kelvin on its dayside, conditions that likely stripped away any atmosphere and left a bare, tidally locked rock.
That composition undercuts earlier hints of Earth-style tectonics; researchers said plate tectonics likely does not operate there and the planet probably contains little water.
JWST also found no clear carbon dioxide or sulfur outgassing, weakening the case for active volcanism and favoring a dead, weathered world more akin to Mercury.
The team has already gathered more JWST data to distinguish between fresh rock slabs and impact-made regolith, a method they say could extend to other rocky exoplanets.
Webb can now perform planetary autopsies from light-years away. What does this 'dead' world tell us about Earth's future?
This dead world orbits the galaxy's most common star type. Are living planets like Earth the ultimate cosmic rarity?
One side is scorched, the other frozen. Could this extreme divide create a completely bizarre and alien geology?
Exogeology Begins: JWST Probes the Basaltic Surface of LHS 3844 b, a Super-Earth 48 Light-Years Away
Overview
In May 2026, the James Webb Space Telescope (JWST) made history by directly probing the surface of the rocky exoplanet LHS 3844 b, marking the beginning of exogeology—a new era focused on studying exoplanetary surfaces. Using its advanced Mid-Infrared Instrument (MIRI), JWST detected and analyzed the planet’s surface features, revealing a world very different from Earth. Scientists found that LHS 3844 b lacks a silicate crust and contains very little water, suggesting that Earth-like plate tectonics are absent or ineffective. This discovery highlights the diversity of rocky planets and opens new paths for understanding planetary evolution.