Saturn’s rings steal the show in a new image from the Webb Telescope – Ars Technica

The James Webb Space Telescope first spotted Saturn, completing a family photo of the solar system’s ring planets nearly a year after the mission’s first image was released.

A near infrared webcam captured an image of Saturn on June 25. The scientists added an orange color to the monochrome image to produce the image, which was released on Friday.

The image shows Saturn’s iconic ice rings glowing around the giant disk of gas, which appears darker in the near infrared due to the absorption of sunlight by methane molecules suspended in the planet’s atmosphere.

Webb pointed his 21.3-foot (6.5-meter) gold-coated mirror at Saturn as part of a monitoring program to test the telescope’s ability to detect fainter moons. The observations included many deep exposures of Saturn that astronomers are still analyzing to probe the planet’s faint rings and search for undiscovered moons.

There are 146 known moons in orbit around Saturn, ranging in size from larger than the planet Mercury to the size of a sports arena, more than any other planet in the solar system, according to NASA.

“Any newly discovered moons can help scientists piece together a more complete picture of Saturn’s current system, as well as its past,” NASA said in a blog post published with the new Saturn image.

Three of Saturn’s moons visible to the planet’s left from Webb’s view: Dione, Enceladus, and Tethys are visible as points of light. Each is the size of a large US state.

Recent observations of Enceladus using Webb’s Near Infrared Spectrometer instrument revealed a flow of water vapor extending more than 6,000 miles (10,000 kilometers) into space, 20 times the moon’s diameter. Scientists say Enceladus is one of the most promising locations in the solar system to search for signs of life because it harbors a watery ocean beneath a global ice crust.

NASA’s Cassini orbiter flew by Enceladus several times before its mission ended in 2017. Cassini spotted similar plumes of water erupting through cracks in Enceladus’ ice cap and flew through the jets to sample particles coming from the moon’s ocean depths.

The Cassini spacecraft captured views of Saturn at a higher resolution than Webb, but with the Cassini mission winding down, Webb is the primary tool scientists will use to continue studying Enceladus and Saturn for at least the next decade.

There is currently no mission on the books to visit Enceladus. NASA’s robotic Dragonfly mission is scheduled to launch toward Saturn in 2027, but it will focus on exploring Titan, Saturn’s largest moon.

The first science images from Webb were released nearly a year ago, showing the promise of a $10 billion mission to see deeper into the universe than ever before. Observations within the solar system are just part of Webb’s science portfolio, along with science topics such as studying the formation of the first galaxies after the Big Bang and searching for planets around other stars that might contain the ingredients for life.

Webb’s science teams have previously released stunning views of the Solar System’s other ringed planets – Jupiter, Neptune and Uranus – along with their first observations of Mars.

Stationed about a million miles from Earth, Webb is unable to observe the Moon, Mercury, or Venus because they are too bright or too close to the Sun.