NASA’s James Webb Space Telescope has captured a stunning image of the solar system’s seventh planet, Uranus, which showcases its dramatic rings and bright features in the planet’s atmosphere.
The image, which was taken by Webb’s Near-Infrared Camera (NIRCam), combines data from two filters at 1.4 and 3.0 microns, shown in blue and orange, respectively. The planet appears to have a blue hue in the resulting representative-color image.
The sensitivity of Webb’s NIRCam has allowed scientists to observe the faintest dusty rings around Uranus, which have only been previously imaged by two other facilities: the Voyager 2 spacecraft as it flew past the planet in 1986, and the Keck Observatory with advanced adaptive optics.
“With the infrared wavelengths and extra sensitivity of Webb, we see more detail, showing how dynamic the atmosphere of Uranus really is,” said Heidi Hammel, executive vice president of the Association of Universities for Research in Astronomy.
Uranus is unique in that it rotates on its side, at roughly a 90-degree angle from the plane of its orbit, causing extreme seasons as the planet’s poles experience many years of constant sunlight followed by an equal number of years of complete darkness.
Currently, it is late spring for the northern pole, which is visible in the image; Uranus’ northern summer will be in 2028. When Voyager 2 visited Uranus, it was summer at the south pole, which is now on the ‘dark side’ of the planet, out of view and facing the darkness of space.
Webb’s image also reveals a unique polar cap at the right side of the planet, which appears when the pole enters direct sunlight in the summer and disappears in the fall. The polar cap is a mystery to scientists, and the Webb data may help explain its mechanism.
The image also shows a subtle enhanced brightening at the center of the polar cap, which has not been seen as clearly with other powerful telescopes like the Hubble Space Telescope and Keck Observatory.
At the edge of the polar cap lies a bright cloud, as well as a few fainter extended features just beyond the cap’s edge. A second very bright cloud is seen at the planet’s left limb. These clouds are typical for Uranus in infrared wavelengths and are likely connected to storm activity.
Uranus is characterized as an ice giant due to the chemical makeup of its interior. Most of its mass is thought to be a hot, dense fluid of “icy” materials, such as water, methane, and ammonia, above a small rocky core.
Uranus has 13 known rings, and 11 of them are visible in the Webb image. Nine of the rings are classified as the main rings of the planet, and two are the fainter dusty rings that were discovered during the Voyager 2 flyby in 1986. Scientists expect that future Webb images of Uranus will reveal the two faint outer rings that were discovered with Hubble during the 2007 ring-plane crossing.
Webb also captured many of Uranus’ 27 known moons, with the six brightest identified in the wide-view image. This was only a short, 12-minute exposure image of Uranus with just two filters. However, scientists believe that this is just the beginning of what Webb can do when observing this mysterious planet.
The National Academies of Sciences, Engineering, and Medicine identified Uranus science as a priority in its 2023-2033 Planetary Science and Astrobiology decadal survey, and additional studies of Uranus are happening now. Scientists are excited to continue exploring this intriguing and unique planet with the James Webb Space Telescope.
More about Uranus
Uranus is the seventh planet from the Sun in our solar system and the third largest planet by size. It is unique among the planets in our solar system because it rotates on its side, with its poles pointing towards and away from the Sun. This unusual axial tilt is thought to have been caused by a collision with a planet-sized object early in the history of the solar system.
Uranus is often referred to as an “ice giant” because it is composed mainly of ices such as water, methane, and ammonia, as well as rock and metal. Its atmosphere is primarily made up of hydrogen and helium, with trace amounts of methane that give the planet its distinctive blue-green color.
Uranus has a system of 27 known moons, the largest of which is called Titania. The moons of Uranus are named after characters from the works of William Shakespeare and Alexander Pope.
Uranus was first observed by William Herschel in 1781, making it the first planet to be discovered in modern times. Because it is so far from the Sun, Uranus takes about 84 Earth years to complete one orbit, and its year is nearly 30 Earth years longer than its day.
Although Uranus has been visited by only one spacecraft, Voyager 2, in 1986, astronomers continue to study the planet using ground-based telescopes and space-based observatories such as the Hubble Space Telescope. Scientists hope to learn more about Uranus and its unique features, such as its tilted magnetic field and the strange behavior of its atmosphere, in the years to come.
What is the James Webb Space Telescope?
The James Webb Space Telescope (JWST) is a large, space-based observatory designed to observe the universe in infrared light. It is named after James E. Webb, who served as the second administrator of NASA from 1961 to 1968 and played a significant role in the Apollo program.
JWST is a collaborative project between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). It is scheduled to be launched in late 2021 (as of my knowledge cutoff), and will be positioned at the second Lagrange point (L2), which is located about 1.5 million kilometers (about 930,000 miles) from Earth.
The telescope has a large primary mirror, 6.5 meters (about 21 feet) in diameter, which is made of 18 hexagonal segments. It also has four scientific instruments that will allow it to observe the universe in unprecedented detail. These instruments include a near-infrared camera, a near-infrared spectrograph, a mid-infrared instrument, and a fine guidance sensor/near-infrared imager and slitless spectrograph.
JWST’s observations will help us to better understand the early universe, the formation of galaxies and stars, and the properties of exoplanets, among other things. It is expected to be a major tool for astrophysics and cosmology research for many years to come.
Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.