The NASA/ESA/CSA James Webb Space Telescope has turned its gaze toward the unusual and enigmatic ice giant Uranus, as reported by the European Space Agency (ESA).
In this way, Webb captured this world with rings, moons, storms and other atmospheric features, including a seasonal polar cap. The image expands on a two-color version published earlier this year, adding additional wavelength coverage for a more detailed view.
The telescope has captured the faint inner and outer rings of Uranus, including the elusive, extremely faint and diffuse Zeta ring, the closest to the planet. It also captured images of many of the planet’s 27 known moons, including some small moons within the rings.
At visible wavelengths, Uranus appeared as a calm, solid blue sphere. At infrared wavelengths, Webb is revealing a strange, dynamic ice world full of exciting atmospheric features.
One of the most striking is the planet’s seasonal north polar cap. Compared to the image from earlier this year, some details of the cap are easier to see in these new images. These include the bright, white inner cap and the dark stripe at the bottom of the polar cap, towards the lower latitudes.
Several bright storms can also be seen near and below the southern edge of the polar cap. The number of these storms and their frequency and location in Uranus’s atmosphere may be due to a combination of seasonal and meteorological effects.
The polar cap becomes prominent when the planet’s pole begins to point toward the Sun, as it approaches the solstice and receives more sunlight. Uranus will reach its next solstice in 2028, and astronomers are eager to observe possible changes in the structure of these features.
Webb will help unravel the seasonal and meteorological effects that influence Uranus’ storms, which is crucial for astronomers to understand the planet’s complex atmosphere.
Because Uranus orbits sideways with an inclination of about 98 degrees, it has the most extreme seasons in the Solar System. For almost a quarter of each Uranian year, the Sun shines on one pole, plunging the other half of the planet into a dark, prolonged 21-year winter.
With Webb’s “unmatched infrared resolution and sensitivity,” astronomers can now see Uranus and its unique features “with groundbreaking clarity.”
Uranus can help astronomers understand how the many exoplanets of similar size discovered in recent decades work, how planets of this size work, what their meteorology is like, and how they formed. This, in turn, can help understand the solar system as a whole by placing it in a broader context.
