Recently, the James Webb Telescope released a celebratory new image showing the fascinating ring-like structure of Uranus. While these rings are difficult to see at visible wavelengths, that's probably why you've never associated Uranus with rings like Saturn. However, these rings appear exceptionally bright at the near-infrared wavelengths operated by the Webb telescope's instruments.
The image, taken by the Webb telescope's Nircam instrument, shows the annular structure in more detail than previous images of Uranus from the Webb telescope, released earlier this year. This new image adds new wavelengths to the previous one, which helps to show more rings, including the rarely seen Zeta ring, which is a very faint ring of material close to the planet's surface — just a few hundred kilometers from the clouds. In addition, the image shows several of Uranus's 27 moons, some of which are located outside the ring, and some of which are even inside the ring.
The image also reveals features of Uranus' surface, especially its polar ice cap. The bright white spot is the center of the ice cap, and the dark area around it is the bottom of the ice cap. We got this special view of Uranus almost directly facing us because of the planet's strange rotation pattern. It is extremely tilted, and the planet is almost completely turned on its side in orbit, which means that during the long summer months, the sun shines on its north pole almost constantly.
Summer in the Northern Hemisphere lasts up to 21 years on Earth, and it is thought that this affects the weather of the planet, which experiences a lot of sunlight at one end and darkness at the other. Uranus also boasts striking storms that appear in the image as highlights on the bottom edge of the Arctic ice cap.
This is an amazing astronomical discovery that once again demonstrates the remarkable performance of the James Webb telescope and our endless exploration of the universe.
post by tom