Observations with the International Ultraviolet Explorer (IUE) during the impacts of the fragments of comet D/Shoemaker‐Levy 9 with Jupiter show far‐UV emissions from the impact sites within a ∼10 min time scale. Positive detections of H2 Lyman and Werner band (1230–1620 Å) and H‐Lyα emissions are made for impacts K and S, and marginally for P2. No thermal continuum is observed. The radiated far‐UV output was >1021 ergs. The H2 spectrum is consistent with electron collisional excitation if significant CH4 absorption is included. Such emissions could result from plasma processes generated by the impacts. Non‐thermal excitation by the high altitude entry and explosion shocks may also be relevant. Emissions by Al+ (1671 Å) and C (1657 Å) of cometary origin are tentatively identified.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)