JWST Reveals Complex Atmosphere of Starless Object SIMP 0136

An international team of researchers, using the James Webb Space Telescope (JWST), has discovered that brightness variations in the starless, planet-mass object SIMP 0136 are due to complex atmospheric factors, not solely clouds. JWST monitored SIMP 0136 across two full rotation periods, detecting variations in cloud layers, temperature, and carbon chemistry. SIMP 0136, located 20 light-years from Earth, is a rapidly rotating, free-floating object with approximately 13 times the mass of Jupiter. It is the brightest object of its kind in the northern sky, allowing direct observation without light pollution from a host star. Webb's NIRSpec captured thousands of spectra, revealing distinct light curves influenced by different atmospheric depths. Researchers identified variations linked to iron and silicate clouds, temperature-related hot spots, and carbon monoxide/dioxide, indicating a dynamic atmosphere. These findings show that molecular abundances can vary across the object and over time, which has implications for studying exoplanets.