Probing for plumes in observations of Europa in transit over Jupiter

In 2016 Sparks et al. reported evidence of water plumes above the Galilean moon Europa. Their method consisted of creating a model image of Europa transiting Jupiter and comparing it with a far-ultraviolet observation from the Hubble Space Telescope. In 2020 Giono et al. reported discrepancies in the method and improved upon in. Sparks’ team commissioned a total of 51 transit images but only 10 were used in the original paper from Sparks et al. Here an attempt to use the expanded method from Giono et al. on all 51 images is reported, with changes made to accommodate the varying quality of the individual transit images. The original method, while clever, is deemed untrustworthy until better modelling can be made, and the discussion includes possible sources of and solutions to the systematic flaws.