JWST reveals LHS 3844 b has a dark, basalt-like surface with no volcanic gases

Star system: LHS 3844 | Distance from the Sun: 48.5 light years

LHS 3844 b is a rocky exoplanet whose surface was studied using mid-infrared spectroscopy from the James Webb Space Telescope. The planet's thermal emission spectrum between 5 and 12 microns matches that of a dark, low-silica surface, such as basalt or olivine-rich rock. The data rule out the presence of fresh powdery surfaces, but space weathering could darken such materials to match the observations.

The spectrum shows no evidence for significant amounts of volcanic gases like carbon dioxide or sulfur dioxide, with strict upper limits set by the data. This suggests that LHS 3844 b has an old, weathered surface and lacks an atmosphere rich in volcanic gases. The findings provide direct clues about the planet's geology and suggest that its surface is similar to basaltic lava flows found on the Moon or Mercury.

These results demonstrate the power of JWST to study the surfaces of rocky exoplanets and reveal their geologic history, even for planets with no detectable atmosphere.

Key findings
- LHS 3844 b has a dark, basalt-like surface
- No evidence for fresh powder or significant volcanic gases
- Surface is likely old and weathered by space
- JWST can directly characterize rocky exoplanet surfaces
- Results provide clues to the planet's geologic history

Scientific study

The dark and featureless surface of rocky exoplanet LHS 3844 b from JWST mid-infrared spectroscopy (external link)