Images of the Jupiter impact site obtained at 12.3 μm, sensitive to both upper tropospheric temperatures (note the fine-scale structure in panel a)) and emission from stratospheric C₂H₆. Panels a) and b) show the reduced images from IRTF/MIRSI and VLT/VISIR, respectively, with white arrows indicating the impact streak. These are cylindrically reprojected in panels c)−f) for several dates, and show that the excess emission was undetectable above the noise on August 16 (which had the poorest seeing of all the dates sampled). The broad circular artefact and dark region in the lower right of panel d), and the striations in panel e), are problems associated with striping in the VLT/VISIR images and proximity to the planetary limb. Stripes were not completely removed by the median filtering algorithm employed in the reduction. All images were obtained in 12.3-μm filters.