Enceladus (NIRCam Image)

Images from the NASA/ESA/CSA James Webb Space Telescope’s NIRCam (Near-Infrared Camera) show a water vapour plume jetting from the south pole of Saturn’s moon Enceladus, extending out 40 times the size of the moon itself. The inset, an image from the Cassini orbiter, emphasises how small Enceladus appears in the Webb image compared to the water plume.

Webb is allowing researchers, for the first time, to see directly how this plume feeds the water supply for the entire system of Saturn and its rings. By analysing the Webb data, astronomers have determined roughly 30 percent of the water stays within a torus, a fuzzy doughnut of water that is co-located with Saturn’s E-ring, and the other 70 percent escapes to supply the rest of the Saturnian system with water.

Enceladus, an ocean world about four percent the size of Earth at just 505 kilometres across, is one of the most exciting scientific targets in our Solar System in the search for life beyond Earth. A global reservoir of salty water sits below the moon’s icy outer crust, and geyser-like volcanoes spew jets of ice particles, water vapour, and organic chemicals out of crevices in the moon’s surface informally called ‘tiger stripes’.

Webb’s NIRCam was built by a team at the University of Arizona and Lockheed Martin’s Advanced Technology Center.

[Image description: The two-part graphic shows a clearer image of a bright white circular moon at top left in a box. It is labelled Enceladus (Cassini). The majority of the graphic shows Webb’s image, which appears pixelated. At the bottom is the label, plume (Webb).]