JWST Reveals an Airless, 30% Bigger Rocky World Orbiting a Red Dwarf

Using JWST's MIRI to measure mid-infrared emissions, scientists studied the rocky, tidally locked exoplanet LHS 3844b, about 50 light-years away. The dayside reaches around 1,000 K, and the spectrum implies a basaltic/mantle-like surface with little to no atmosphere, suggesting a Mercury-like, geologically inactive world rather than an Earth-like tectonically active planet. Researchers plan additional JWST observations to better constrain the crust and surface properties; the findings were published in Nature Astronomy.