New Uranus images showcase rings, moons … and galaxies

This image of Uranus from the Near-Infrared Camera (NIRCam) on NASA’s James Webb Space Telescope exquisitely captures Uranus’s seasonal north polar cap and dim inner and outer rings. This Webb image also shows 9 of the planet’s 27 moons. Starting clockwise at 2 o’clock, they are: Rosalind, Puck, Belinda, Desdemona, Cressida, Bianca, Portia, Juliet, and Perdita. Image via NASA/ ESA/ CSA/ STScI.

NASA published this original article on December 18, 2023. Edits by EarthSky.

Uranus in all its glory

NASA’s James Webb Space Telescope recently trained its sights on unusual and enigmatic Uranus. Uranus is the 7th planet from the sun: an ice giant that spins on its side. Webb captured this dynamic world with rings, moons, storms and other atmospheric features, including a seasonal polar cap. The image expands upon a two-color version released earlier this year, adding additional wavelength coverage for a more detailed look.

Webb captured Uranus’ dim inner and outer rings, including the elusive Zeta ring. The Zeta ring is the extremely faint and diffuse ring closest to the planet. Webb also imaged many of the planet’s 27 known moons, even seeing some small moons within the rings.

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This wide-field image of Uranus from Webb’s NIRCam shows the planet amid a smattering of distant background galaxies. The galaxies are the small hazy-looking or elongated objects. This image also includes 14 of the planet’s 27 moons. The 14 here are Oberon, Titania, Umbriel, Juliet, Perdita, Rosalind, Puck, Belinda, Desdemona, Cressida, Ariel, Miranda, Bianca and Portia. Image via NASA/ ESA/ CSA/ STScI.

Seasons and storms

Voyager 2 took visible-light images of Uranus in the 1980s. Uranus appeared as a placid, solid blue ball. In infrared wavelengths, Webb is revealing a strange and dynamic ice world filled with exciting atmospheric features.

One of the most striking of these is the planet’s seasonal north polar cloud cap. Some details are easier to see in these newer images. These include the bright, white, inner cap and the dark lane in the bottom of the polar cap, toward the lower latitudes.

We can also see several bright storms near and below the southern border of the polar cap. The number of these storms, and how frequently and where they appear in Uranus’s atmosphere, might be due to a combination of seasonal and meteorological effects.

The polar cap appears to become more prominent when the planet’s pole begins to point toward the sun, as it approaches its solstice and receives more sunlight. Uranus reaches its next solstice in 2028. And astronomers are eager to watch any possible changes in the structure of these features. Disentangling the seasonal and meteorological effects that influence Uranus’s storms is critical to help astronomers understand the planet’s complex atmosphere.

Because Uranus spins on its side at a tilt of about 98 degrees, it has the most extreme seasons in the solar system. For nearly a quarter of each Uranian year, the sun shines over one pole, plunging the other half of the planet into a dark, 21-year-long winter.

Future missions and exoplanets

The detailed new images, especially of the close-in Zeta ring, will be invaluable to planning any future missions to Uranus.

Uranus can also serve as a proxy for studying the nearly 2,000 similarly sized exoplanets discovered in the last few decades. It can help astronomers understand how planets of this size work, what their meteorology is like, and how they formed. This can in turn help us understand our own solar system as a whole by placing it in a larger context.

View larger. | Annotated wide-field compass image of Uranus with some of its 27 moons and a few prominent stars (with characteristic diffraction spikes) labeled. Image via NASA/ ESA/ CSA/ STScI.

Bottom line: The Webb space telescope has taken new images of Uranus. Get a better look at the planet, its rings, moons, and the distant background galaxies.

Via NASA

The post New Uranus images showcase rings, moons … and galaxies first appeared on EarthSky.