NASA’s James Webb Space Telescope has provided new insights into the atmosphere of SIMP 0136, a free-floating planetary-mass object located 20 light-years from Earth. The telescope has captured detailed images of patchy cloud layers, high-altitude hot spots, and variations in chemistry around this rapidly rotating object.
SIMP 0136 is not an exoplanet, but rather a brown dwarf that is roughly 13 times the mass of Jupiter. Its unique characteristics make it an ideal target for studying exo-meteorology, as it can be observed without interference from its host star.
Using the Webb Telescope’s Near-Infrared Spectrograph and Mid-Infrared Instrument, researchers have obtained thousands of individual spectra showing the brightness patterns of hundreds of colors of infrared light coming from different parts of the object’s atmosphere. The results reveal variations in cloud cover, temperature, and chemistry that provide a three-dimensional picture of gas giants within and beyond our solar system.
The team noticed distinct light-curve shapes, indicating that multiple factors are affecting the brightness variations. By analyzing the spectra, they identified different wavelengths originating from various depths in the atmosphere. Patchy clouds made of iron particles and tiny grains of silicate minerals were found to be related to the brightness patterns.
Additionally, the researchers detected bright “hot spots” at high altitudes, which could be linked to auroras or upwelling of hot gas from deeper in the atmosphere. The study also revealed variations in atmospheric carbon chemistry, with pockets of carbon monoxide and carbon dioxide rotating in and out of view or undergoing chemical reactions.
This research was conducted as part of the Webb Telescope’s General Observer Program 3548. The James Webb Space Telescope is solving mysteries in our solar system and beyond, providing new insights into the origins of the universe and our place within it.
Source: https://webbtelescope.org/contents/news-releases/2025/news-2025-106