JWST detects water ice clouds on nearby Jupiter like exoplanet

Wednesday 22 April 2026 - 15:20

By: Dakir Madiha

JWST detects water ice clouds on nearby Jupiter like exoplanet

Astronomers using the James Webb Space Telescope have identified evidence of water ice clouds in the atmosphere of Epsilon Indi Ab, a massive planet located about 12 light years from Earth. The findings, published in Astrophysical Journal Letters, challenge widely used atmospheric models and mark a step forward in the study of distant worlds.

The research team, led by scientists at the Max Planck Institute for Astronomy, used the telescope’s mid infrared instrument to directly image the planet. Epsilon Indi Ab is a super Jupiter with a mass roughly 7.6 times that of Jupiter and surface temperatures ranging from minus 70 to 20 degrees Celsius. By comparing observations at wavelengths of 10.6 and 11.3 micrometers, the team measured ammonia levels in the atmosphere and found them lower than expected.

Researchers concluded that thick but patchy clouds of water ice provide the most consistent explanation for the anomaly. These clouds resemble high altitude cirrus on Earth and can obscure atmospheric signals, reducing the apparent concentration of ammonia. Similar patterns have been observed in other cold gas giants, which appear dimmer than predicted in near infrared observations.

The findings suggest that many existing atmospheric models for exoplanets require revision. Most current models exclude clouds because they add computational complexity, but the new data indicates that such simplifications limit accuracy. Scientists involved in the study say the ability to detect these features reflects rapid advances in observational capabilities, allowing deeper analysis of planetary atmospheres.

The results also have implications for the future search for Earth like planets. Techniques used to identify clouds on gas giants could be adapted to study smaller, rocky worlds. Researchers note that the Webb telescope provides a first opportunity to analyze Jupiter like planets from distant systems in detail, offering a testing ground for methods that could eventually detect habitable environments.

Future missions are expected to build on this progress. The Nancy Grace Roman Space Telescope, scheduled for launch later this decade, may enable direct observation of highly reflective cloud structures on distant planets, further refining the search for worlds similar to Earth.