The James Webb Space Telescope (JWST) has provided groundbreaking insights into the atmosphere of SIMP-0136, a rogue planet approximately 20 light-years away. This celestial body, about 12.7 times the mass of Jupiter and 1.2 times its radius, offers a unique opportunity to study starless planets. SIMP-0136's rapid rotation of 2.4 hours allows for detailed observation of its dynamic atmosphere.
One of the most significant discoveries is the presence of a thermal inversion in SIMP-0136's atmosphere, where temperatures increase with altitude, a phenomenon opposite to Earth's atmospheric structure. This inversion is largely driven by intense auroral activity, similar to Earth's Northern Lights but significantly more powerful. These auroras energize the upper atmosphere, leading to temperatures that can exceed 1,500°C, a remarkable feat for a planet not orbiting a star. The planet's magnetic field, estimated to be thousands of times stronger than Jupiter's, is a key factor in this auroral activity and atmospheric heating.
Further analysis revealed a constant cloud cover on SIMP-0136, composed of silicate grains akin to beach sand, which differs from the variable cloud patterns observed on Earth. These silicate clouds maintain a consistent coverage of about 87% across the observed hemisphere. Computational models have been instrumental in enhancing the comprehension of its atmospheric dynamics, revealing chemical weather patterns with varying abundances of carbon dioxide and hydrogen sulfide as the planet rotates. These variations suggest localized storm activity, potentially akin to Jupiter's Great Red Spot. The precise measurements of temperature changes, sometimes less than 5°C, linked to subtle shifts in chemical composition, provide a detailed look at the planet's atmospheric properties. These observations represent some of the most precise measurements of any extra-solar object's atmosphere to date.
The findings challenge conventional understanding of atmospheric processes on starless worlds and offer valuable clues about their formation and evolution, expanding our knowledge of exoplanet atmospheres. The intense magnetic field of SIMP-0136 is also a key factor in its auroral activity and atmospheric heating.