Nasa's Webb telescope captures clearest image of Neptune in decades
NASA reveals the James Webb Space Telescope's capabilities of capturing the clearest images of Neptune and its rings in decades, showing the ice giant in a whole new light.
The James Webb space telescope has captured an image of a luminous Neptune and its delicate rings, located 30 times farther from the Sun than Earth, in detail not seen in decades.
“It has been three decades since we last saw these faint, dusty rings, and this is the first time we’ve seen them in the infrared," said Heidi Hammel in a NASA release, a Neptune system expert and interdisciplinary scientist for Webb.
Webb’s unmatched infrared imaging capability has given a new glimpse into Neptune’s atmosphere, said Mark McCaughrean, a senior adviser for science and exploration at the European Space Agency who has worked for more than 20 years at the Webb project.
The telescope “takes all that glare and background away” in a way “we can start to tease out the atmospheric composition” of the planet, McCaughrean added.
In images the Hubble space telescope took previously, Neptune seems as deep blue due to methane in its atmosphere. However, Webb’s primary imager NIRCam captured near-infrared wavelengths that show the planet as greyish white, with icy clouds streaking the surface.
In visible light, Neptune appears blue due to small amounts of methane gas in its atmosphere. Webb’s NIRCam instrument instead observed Neptune at near-infrared wavelengths, so Neptune doesn’t look so blue! pic.twitter.com/aZZa8B8x4f— NASA Webb Telescope (@NASAWebb) September 21, 2022
“The rings are more reflective in the infrared,” McCaughrean said, “so they’re much easier to see.”
In the new image, an “intriguing brightness” can be seen near the top of Neptune, NASA said in a statement. Seven of Neptune’s 14 known moons were also spotted by Webb. What appears to be a very bright star looms over Neptune, but it is in fact Triton, the planet's strange, huge moon haloed with Webb’s famed diffraction spikes.
Hey Neptune. Did you ring? 👋— NASA Webb Telescope (@NASAWebb) September 21, 2022
Webb’s latest image is the clearest look at Neptune's rings in 30+ years, and our first time seeing them in infrared light. Take in Webb's ghostly, ethereal views of the planet and its dust bands, rings and moons: https://t.co/Jd09henF1F #IAC2022 pic.twitter.com/17QNXj23ow
Triton is larger than dwarf planet Pluto, and due to being covered in ice, it appears brighter than Neptune. Meanwhile Neptune “absorbs most of the light falling on it”, McCaughrean said.
Webb has been operational since July and is the most powerful telescope ever built. It has already revealed significant unprecedented information and scientists hope it will herald a new era of discovery.
“The kind of astronomy we’re seeing now was unimaginable five years ago,” McCaughrean said.
“Of course, we knew that it would do this, we built it to do this, it is exactly the machine we designed. But to suddenly start seeing things in these longer wavelengths, which were impossible before … it’s just absolutely remarkable.”