Overview
- Astronomers used JWST’s MIRI coronagraph to directly image Epsilon Indi Ab and compare light at 11.3 micrometers with earlier 10.6 micrometer data to gauge ammonia.
- Epsilon Indi Ab showed less ammonia than models predict, which the team explains as thick, patchy water-ice clouds high in the atmosphere.
- The planet’s mass is about 7.6 times Jupiter’s, its size is similar to Jupiter’s, and its estimated temperature is 200–300 K at a wide orbit around a K-type star roughly 11–12 light-years away.
- The result exposes a gap in common atmospheric models that often skip cloud physics, signaling a need to include cloud formation and particle behavior in future work.
- Researchers will seek more JWST time to study cold Jupiter analogues, and NASA’s upcoming Roman Space Telescope is expected to help by directly detecting bright, reflective ice clouds.