A stunning wide-field picture of Uranus has been obtained by NASA’s James Webb Space Telescope. The most potent observatory ever put into orbit examined the planet’s seasonal north polar cap, inner and outer rings, and even some of Uranus’ moons using its near-infrared camera (NIRCam).
The photo from this week is significantly more detailed than the one that Webb took back in April. That picture was the greatest one we had seen of Uranus since NASA’s Voyager 2 passed past in the middle of the 1980s, at the time. This week’s image of Uranus isn’t all that dissimilar from last week’s, despite the astronomical difference in definition between Voyager 2’s glance and Webb’s image from April. Nevertheless, it lets us see a lot of fascinating features.
The seasonal north polar cloud cover of Uranus, which is more evident than ever in the image above, is the most timely of all. This polar cap gets more light and gets more noticeable when the planet’s pole moves nearer the Sun. NASA also notes that numerous bright storms are circling around and below the southern edge of the polar cap, raising concerns about potential variations in both the storms and the polar cap itself as Uranus gets closer to solstice. By the time the ice giant reaches solstice in 2028, astronomers will have ample opportunity to observe associated seasonal and meteorological phenomena.
Many of Uranus’ moons are another striking difference between the image published this week and the one from April. This new view enables us to see Belinda, Bianca, Cressida, Desdemona, Juliet, Perdita, Portia, Puck, and Rosalind—small, dim moons that orbit closer to Uranus itself, making them historically difficult to see. The image from earlier this year wasn’t quite sharp enough to include any of the ice giant’s 27 moons. Four of Uranus’ largest and brightest moons—Ariel, Miranda, Titania, and Umbriel—are also visible in Webb’s image.
But the planet’s collection of ice rings is one of its most notable characteristics. Zeta, the faint and diffuse innermost ring of Uranus, is now visible to us after we had a fairly good look at them in April. The outer rings of Uranus are very vivid, providing us with what NASA refers to as a “exquisite” image of the ice giant’s recognizable profile.
With its unparalleled detail, Webb’s work will help NASA get ready for upcoming flights to Uranus, so it’s more than simply a nice picture. The organization adds that because Uranus provides information on meteorology and planet formation, it can be used as a stand-in for about 2,000 exoplanets.