Free Astronomy Magazine November-December 2025

21 NOVEMBER-DECEMBER 2025 ASTRO PUBLISHING telescope in Chile, one half of the In- ternational Gemini Observatory, funded in part by the U.S. National Science Foundation (NSF) and oper- ated by NSF NOIRLab. This laid the groundwork for further investiga- tions, led by NOIRLab astronomer Aaron Meisner, using NASA’s James Webb Space Telescope. “The Acci- dent is extremely faint, and Gemini South remains the only ground- based telescope that’s so far been able to detect it,” says Meisner, co- author of the article that presented these results in Nature . “The Gemini detection set the stage for observa- tions with JWST by allowing us to es- timate the exposure time we would need to probe this enigmatic ob- ject’s deep atmospheric layers and get useful near-infrared data about its composition.” The observations from Webb revealed a surprise. In The Accident’s atmosphere, the team found a conclusive signature of the chemical silane — silicon bonded with four hydrogen atoms. Planetary scientists have long pre- dicted that this molecule exists in gas giants and that it plays an im- T his artist’s illustration shows a brown dwarf that hosts an atmosphere filled with gas and dust clouds. A new study on an ancient brown dwarf called The Accident has unlocked clues into how clouds like these form on gas giant planets and how the time at which they formed can impact their chemical composition. [NOIRLab/NSF/AURA/R. Proctor. Image Pro- cessing: M. Zamani (NSF NOIRLab). Produced in part with SpaceEngine PRO]