JWST detects an atmosphere around a rocky lava exoplanet
Using the James Webb Space Telescope, researchers found evidence that HD 3167 b, a rocky super-Earth 154 light-years away, has an atmosphere. The planet orbits its star in about one Earth day and is extremely hot, making the apparent atmosphere unexpected. Scientists say studying such lava worlds could illuminate how rocky planets retain atmospheres and what early Earth was like.
HD 3167 b sits about 154 light-years away in Pisces. This rocky super-Earth is called a lava world because it circles its star in roughly one Earth day, leaving it intensely hot. The study appears in The Astrophysical Journal Letters and was led by University of Chicago researchers.
Webb’s mid-infrared observations help estimate exoplanet temperatures, which can reveal whether an atmosphere is likely. A survey led by Megan Weiner Mansfield is examining ten ultra-hot lava worlds to test whether a temperature threshold separates bare rocky planets from those with atmospheres. Five terrestrial planets with atmospheres found so far are ultra-hot; this one is the coolest lava world yet with such evidence.
The finding may shape how astronomers prioritize rocky exoplanets in the search for habitable environments, though HD 3167 b itself is far too hot for life. It could also deepen public interest in JWST and planetary science, influencing museum programming, education, and science communication. For researchers, it may sharpen questions about atmospheric retention and early Earth, guiding future observations and funding priorities without offering immediate technological or everyday benefits.