NASA's JWST captures Uranus's ring system in stunning details
NASA's James Webb Space Telescope has captured extraordinary details of Uranus, ranging from the planet's spectacular ring system to features of the atmosphere. Uranus has 13 known rings out of which 11 are visible in Webb's image. Some of these rings are so bright that they appear to merge but Webb's onboard Near Infrared Camera (NIRCam) has captured almost all of them.
Why does this story matter?
Equipped to conduct observations in infrared wavelengths of light, Webb can peer into the universe better than any other telescope. With its observations, Webb has yet again stunned astronomers, providing valuable insights into the ice giant, Uranus. The $10 billion observatory, developed by NASA along with European Space Agency and the Canadian Space Agency, is touted to be the world's most powerful space telescope.
Uranus has 9 main rings
Out of Uranus's 13 total rings, 11 are visible, wherein nine are classified as the main rings of the planet. The remaining two are faint dusty rings that were discovered in 1986 by NASA's Voyager 2 mission. Uranus's faintest dusty rings have only been captured by two other facilities before Webb. One was Voyager 2 and the other, more recently, by the Keck Observatory.
Why is Uranus called an ice giant?
Uranus is classified as an ice giant because of the chemical makeup of its interior. The majority of the planet's mass is considered to be composed of dense fluid of icy materials like water, methane, and ammonia, above a small rocky core.
Uranus's tilt causes it to have extreme seasons
Uranus is a pretty peculiar planet. It rotates on its side and is the only planet in the solar system whose equator is almost at a right angle to its orbit, with a tilt of 97.77 degrees. This tilt causes it to have extreme seasons. The poles witness several years of continual sunlight, followed by an equal duration of complete darkness.
Uranus's north pole will experience summer only in 2028
Currently, it is late spring at the north pole of Uranus, which is visible in the image. The planet's north pole will experience summer only in 2028. When Voyager 2 paid a visit to Uranus, it was summer at the planet's south pole. Now, the south pole is on the 'dark side' of the planet and is out of view.
The polar cap is a feature unique to Uranus
In the image, toward the right side is a bright area at Uranus's pole facing the Sun, called a polar cap. This area appears to emerge when the pole receives direct sunlight in summer and disappears in fall. Webb uncovered something interesting about the polar cap, which as per NASA is "a subtle enhanced brightening at the center of the cap."
A bright cloud and few other faint features are seen
A bright cloud and a few fainter extended features are seen at the edge of the polar cap. There is also a second very bright cloud seen toward the left limb of the planet. Such clouds are typical for Uranus and can be observed at infrared wavelengths and they are believed to be connected to storm activity, according to NASA.
Other telescopes have not provided such clear details
Other powerful telescopes like the Hubble Space Telescope and Keck Observatory have not been able to see the polar cap quite as clearly as Webb. The credit could be attributed to Webb's NIRCam instrument's unprecedented sensitivity.
Webb captured six of Uranus's 27 known moons
The Webb telescope has also captured six of Uranus's brightest moons, namely Ariel, Puck, Miranda, Umbriel, Titania, and Oberon. The planet has 27 known moons. Some background objects, including several galaxies, can also be spotted in Webb's image. "It is just the tip of the iceberg of what Webb can do when observing this mysterious planet [Uranus]," said NASA in a blog.
