Saturn is widely known for its magnificent ring system, which consists of countless particles ranging in size from tiny grains to large chunks of ice and rock. The rings are primarily made up of ice particles, with traces of rocky material.
These rings reflect sunlight, making them highly visible and contributing to Saturn’s striking appearance.
The James Webb Space Telescope (JWST) is designed to be the successor to the Hubble Space Telescope and is specifically optimized for observations in the infrared range of the electromagnetic spectrum.
The JWST’s powerful instruments and advanced technologies allow it to capture incredibly detailed images and study distant celestial objects with unprecedented precision.
If a new JWST image were to show Saturn’s rings outshining Saturn, it would likely indicate a unique perspective or lighting conditions that emphasize the brightness of the rings.
On June 25, 2023, NASA’s James Webb Space Telescope turned to the famed ringed world Saturn for its first near-infrared observations of the planet. The initial imagery from Webb’s NIRCam (Near-Infrared Camera) is already fascinating to researchers.
Saturn itself appears extremely dark at this infrared wavelength observed by the telescope, as methane gas absorbs almost all of the sunlight falling into the atmosphere. However, the icy rings stay relatively bright, leading to the unusual appearance of Saturn in the Webb image.
This image was taken as part of Webb Guaranteed Time Observation program 1247. The program included several very deep exposures of Saturn, which were designed to test the telescope’s capacity to detect faint moons around the planet and its bright rings. Any newly discovered moons could garner important clues about the flow of material in the current Saturn system, as well as its past history.
it’s now seen all four of our gas giants. Saturn, in particular, appears astoundingly different at various wavelengths.
Its hydrogen and helium atmosphere contains traces of ammonia, phosphine, water vapor, and hydrocarbons. In optical light, Saturn appears a yellowish-brown color. Clouds — composed of ammonia crystals, ammonium hydrosulfide, and water — preferentially reflect those colors. But in infrared light, Saturn shows a different side of itself. Only one-third of Jupiter’s mass, similar-sized Saturn generates little internal heat, appearing far fainter.
Even in infrared wavelengths, Saturn’s appearance is dominated by reflected sunlight. It’s northern hemisphere summer on Saturn, but Saturn’s north pole currently appears particularly dark. This suggests that stratospheric aerosols, made of absorptive hydrocarbons, play a major role.
Those aerosols are likely shaped by a planetary-scale atmospheric phenomenon called gravity waves. Composed almost entirely of water ice, they’re too cool to radiate thermally. But water ice is incredibly reflective, even in infrared light.
JWST sees reflected sunlight from Saturn’s rings and in water-ice plumes from Enceladus. Future JWST views will reveal fainter, thinner, and even more diffuse Saturnian rings.
(ref-bigthink)