JWST snaps clearest image of Neptune’s rings since Voyager 2

NASA’s latest and greatest space telescope recently set its sights on the solar system’s most distant planet — and the results are stunning.

NASA’s James Webb Space Telescope (JWST) used its Near-Infrared Camera (NIRCam) to capture this incredible shot of Neptune’s turbulent atmosphere and ethereal ring system. Neptune’s moon Triton, at left, outshines the planet because Neptune’s atmosphere is rich in methane gas, which absorbs light at the wavelengths JWST is sensitive to. IMAGE: NASA, ESA, CSA, STScI; IMAGE PROCESSING: Joseph DePasquale (STScI)

Neptune’s delicate rings and even fainter dust bands come into clear focus in this recent image captured by NASA’s James Webb Space Telescope (JWST).

Neptune, the solar system's most distant planet, is difficult to photograph since it is 30 times further away from the Sun than Earth. However, the JWST's space-based vantage point, flawless stability, and remarkably huge (21-foot-diameter) primary mirror allowed the telescope to catch Neptune's characteristics with clarity not seen in more than 30 years.

Neptune's ethereal ring structure is perhaps the most remarkable part of the new photograph. Some of these rings are so weak that they haven't been seen since NASA's Voyager 2 spacecraft flew by Neptune for the first time in 1989. "We haven't seen those faint, dusty bands in three decades, and this is the first time we've observed them in infrared," said Heidi Hammel, a Neptune expert and JWST scientist, in a press statement.

Neptune has 14 known moons, and seven of them are visible in this labeled version of the recent JWST image. Triton, at top left, reflects an average of 70 percent of the sunlight that strikes it. IMAGE: NASA, ESA, CSA, STScI; IMAGE PROCESSING: Joseph DePasquale (STScI)

The ice giants of the solar system, Neptune and Uranus, have more heavy elements than the gas giants Jupiter and Saturn, which are virtually entirely made up of hydrogen and helium. The ice giants, in particular, have a relative abundance of gaseous methane, which gives them their distinctive blue tint in visual images recorded by the Hubble Space Telescope. (Recent research indicates that Neptune's turbulent atmosphere is more efficient in dispelling haze from its cloud tops than Uranus, giving Neptune a deeper blue look.)

Because methane gas strongly absorbs the wavelengths of light JWST’s Near-Infrared Camera (NIRCam) is sensitive to (0.6 to 5 microns), Neptune appears surprisingly dim in the image above. That’s how Neptune’s nitrogen-covered moon Triton, at top left, manages to outshine the giant planet. High-altitude methane ice, meanwhile, better reflects sunlight, resulting in the bright streaks and spots visible on Neptune’s disk in this shot.

JWST has brought even our solar system's furthest remote world back into the spotlight. With more studies of Neptune and Triton planned over the next year, there will undoubtedly be more spectacular images to come.