SIMBAD references

During the encounter of comet Shoemaker-Levy 9 with Jupiter in July 1994, narrow-band imaging was used to detect changes in methane opacity in the upper atmosphere resulting from the impacts. Of nine debris clouds visible in the data, seven show clear evidence of a significant change, when compared with nearby parts of the disk, in the ratio between the opacity in the optical methane band and that in a near-lying part of the continuum. Typical opacity enhancement is of the order of 30%. The result is found to be corroborated by related data from other sources. Possible reasons for the observed effect are discussed.