Overview
- Published March 16 in Nature Astronomy, the study couples JWST and ground data with interior–atmosphere simulations to interpret L 98-59 d as a global molten world.
- L 98-59 d is about 1.6 times Earth’s radius with a bulk density near 2 g/cm³ (~40% of Earth’s), orbiting a nearby red dwarf roughly 34–35 light-years away.
- The thick atmosphere is hydrogen-rich and sulfur-bearing, including hydrogen sulfide at roughly 10% by volume, consistent with prior JWST detections of sulfur gases.
- Models indicate a magma ocean thousands of kilometers deep, comprising ~70–90% of the planet’s interior radius, which buffers and recycles sulfur over billions of years.
- Researchers conclude the surface exceeds ~1,500°C and is uninhabitable, and they propose this may be the first recognized member of a broader sulfur‑rich, molten planet population to be tested with further JWST observations and ESA’s Ariel and PLATO missions.