Detection of CO

Using JWST/MIRI observations, we report the detection of CO2 ice in the dusty torus of the planetary nebula NGC 6302, an environment generally considered hostile to fragile molecular species and ices due to intense UV irradiation. This detection accompanies cold (20–50 K) gas-phase CO2 along the same sightlines. The ice absorption profile exhibits a double-peak profile, which is characteristic of pure crystalline CO2 ice. The CO2 gas-to-ice ratio is higher by more than an order of magnitude than in young stellar objects, which indicates distinct ice formation or processing mechanisms in evolved stellar environments. This discovery demonstrates that the dusty torus provides sufficient shielding to harbor ice chemistry, and that ice-mediated surface reactions must be incorporated into chemical models of planetary nebulae.