James Webb telescope captured the most spectacular view of Neptune, its rings and moons

The images of the giant ice planet, which was visited by Voyager 2 in 1989, are the clearest ever captured by NASA.

NASA’s James Webb Space Telescope demonstrated its incredible observing capabilities once again, with the clearest image of Neptune ever taken.

Cameras from the advanced space observation post reveal the ice giant planet from a whole new perspective, along with its rings and some of its moons.

Most striking in Webb’s new image is the sharp view of the planet’s rings, some of which had not been seen since NASA’s Voyager 2 became the first spacecraft to observe Neptune during its flyby in 1989. In addition to several narrow, bright rings, Webb’s image clearly shows Neptune’s fainter dust lanes.

“It’s been three decades since we last saw these faint, dusty rings, and this is the first time we’ve seen them in the infrared,” says Heidi Hammel, Neptune systems expert and interdisciplinary team scientist for the Webb telescope.

Webb’s extremely stable and precise image quality makes it possible to detect these very faint rings that are so close to Neptune. Neptune has fascinated researchers since its discovery in 1846. Located 30 times farther from the Sun than Earth, the planet orbits in the remote and dark region of the outer solar system.

At that extreme distance, the Sun is so small and faint that noon on Neptune is similar to a dimly lit twilight on Earth.

This planet is characterized as an ice giant due to the chemical composition of its interior. Compared to the gas giants Jupiter and Saturn, Neptune is much richer in elements heavier than hydrogen and helium.

This is readily apparent in Neptune’s characteristic blue appearance in Hubble Space Telescope images at visible wavelengths, caused by small amounts of gaseous methane.

Webb’s Near Infrared Camera (NIRCam) produces images of objects in the near infrared range between 0.6 and 5 microns, so Neptune does not appear blue to Webb’s instruments. In fact, methane gas absorbs red and infrared light so strongly that the planet is quite dark at these near-infrared wavelengths, except where there are high-altitude clouds.

Such methane ice clouds stand out as bright streaks and spots, reflecting sunlight before it is absorbed by methane gas. Images from other observatories, including the Hubble Space Telescope and the WM Keck Observatory, have recorded these rapidly evolving cloud features over the years.
More subtly, a thin line of brightness encircling the planet’s equator could be a visual cue for the global atmospheric circulation that fuels Neptune’s winds and storms.

The atmosphere sinks and heats up at the equator, and therefore shines brighter in infrared wavelengths than the cooler surrounding gases.

Neptune’s 164-year orbit means that its north pole, at the top of this image, is out of sight for astronomers, but the Webb images suggest an intriguing glow in that area.

A previously known vortex at the south pole is evident in Webb’s view, but for the first time Webb has revealed a continuous band of high-latitude clouds surrounding it.