Evrim Yazgin
Cosmos science journalist
NASA’s James Webb Space Telescope (JWST) has provided its first near-infrared image of the ringed gas giant Saturn, providing another fascinating view of the planet.
The image was taken as part of the Webb Guaranteed Time Observation program 1247. The aim of the program is to test the telescope’s ability to detect faint moons around the planet and its rings. New moons would help astronomers build a more complete picture of Saturn’s planetary system and its history.
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Clearly visible in Webb’s snap are three well-known moons Dione, Enceladus, and Tethys
Saturn itself appears dark in the image as the methane gas in its atmosphere absorbs almost all sunlight striking the planet. The icy rings reflect the sun’s light and shine brightly, leading to a brilliant, detailed display around the darkened gas giant.
Additional deeper exposures not visible in the images shown will allow astronomers to probe the fainter rings around the planet, including the very thin G ring and the diffuse E ring.
Recent observations by Webb showed a large plume jetting from the southern pole of the planet’s sixth-largest moon Enceladus. This column feeds water vapor into Saturn’s E ring.
Initial results of the recent JWST image of Saturn have been announced in a blog post on NASA’s website, but further peer-reviewed studies of the observations are expected in the near future.
Webb has provided a surprising amount of information. Though previous expeditions, the Cassini voyage in particular, have observed the planet’s atmosphere with greater clarity, the JWST examination is the first at this wavelength of light (3.23 micrometres).
Differences between the north and south poles of the planet seen in JWST’s image are consistent with what astronomers already know about Saturn’s seasons. The northern latitudes are currently experiencing Saturnian summer, pointing to its brighter colouration.
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But unexpected darkness at the northern pole suggests unknown seasonal processes.
JWST has now captured images of all four of the solar systems gas giants.
The space telescope’s main brief is to provide clues to answer some of the universe’s deep questions by analysing distant stars and galaxies. But closer to home, many mysteries and unanswered questions remain within our own cosmic backyard.
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