These images of Titan were taken by the NASA/ESA/CSA James Webb Space Telescope on 11 July 2023 (top row) and the ground-based W.M. Keck Observatories on 14 July 2023 (bottom row). They show methane clouds (denoted by the white arrows) appearing at different altitudes in Titan’s northern hemisphere.
On the left side are representative-colour images from both telescopes. In the Webb image light at 1.4 microns is coloured blue, 1.5 microns is green, and 2.0 microns is red (filters F140M, F150W, and F200W, respectively). In the Keck image light at 2.13 microns is coloured blue, 2.12 microns is green, and 2.06 microns is red (H2 1-0, Kp, and He1b, respectively).
In the middle column are single-wavelength images taken by Webb and Keck at 2.12 microns. This wavelength is sensitive to emission from Titan’s lower troposphere. The rightmost images show emission at 1.64 microns (Webb) and 2.17 microns (Keck), which favour higher altitudes, in Titan’s upper troposphere and stratosphere (an atmospheric layer above the troposphere). It demonstrates that the clouds are seen at higher altitudes on July 14 than earlier on July 11, indicative of upward motion.
[Image description: A six-panel graphic with two rows and three columns, showing infrared images of Saturn’s moon Titan. The top row is labeled “Webb, 11 July 2023” and the bottom row is labeled “Keck, 14 July 2023.” The leftmost images are labeled “atmosphere and surface.” They show a mottled globe of brown and yellow with a hazy blue edge. At the top, a white spot that is somewhat faint in the Webb image and brighter in the Keck image has an arrow pointing to it. The middle column is labeled “troposphere” and shows a dark orange globe with a brighter edge. The only features are bright spots near the top and bottom. The top spot is fainter in the Webb image and brighter in the Keck image, and has an arrow pointing to it. The rightmost images are labeled “stratosphere” and also show a dark orange globe with a brighter edge. The top image from Webb is otherwise featureless. The bottom image from Keck, taken three days later, has bright spots near the top and bottom. The top spot has an arrow pointing to it.]
Read more