Discovery of $${{\bf{H}}}_{\mathbf{3}}^{\mathbf{+}}$$ and infrared aurorae at Neptune with JWST

({{rm{H}}}_{3}^{+}) was detected outside the laboratory at Jupiter, Uranus and Saturn more than 30 years ago^1,2,3. It is the dominant molecular ion in hydrogen atmospheres⁴ and the most prevalent molecular ion in interstellar space⁵. This ion,…