Hubble Captures Uranus's Rings on Edge

The images from NASA's Hubble Space Telescope shows how the ring system around the planet Uranus appears at ever more oblique tilts as viewed from Earth - culminating in the rings being seen edge-on in three observing opportunities in 2007. The best of these events appears in the far right image taken with Hubble's Wide Field Planetary Camera 2 on August 14, 2007.
The edge-on rings appear as two spikes above and below the planet. The rings cannot be seen running fully across the face of the planet because the bright glare of the planet has been blocked out in the Hubble photo (a small amount of residual glare appears as a fan- shaped image artifact). A much shorter color exposure of the planet has been photo- composited to show its size and position relative to the ring plane.


The rings were discovered in 1977, so this is the first time for a Uranus ring crossing to be observed from Earth. Earth's orbit around the Sun permits three opportunities to view the rings edge-on: Uranus made its first ring crossing as seen from Earth on May 3; it made its second crossing on August 16; and will cross for the third time on February 20, 2008. Though the last ring crossing relative to Earth will be hidden behind the Sun, most of Earth's premier telescopes, including Keck, Hubble, the European Southern Observatory's Very Large Telescope and the Hale Telescope on Mt. Palomar, plan to focus on the planet again in the days following December 7, 2007. On December 7 the rings will be perfectly edge-on to the Sun.

For additional information, contact:


Ray Villard
Space Telescope Science Institute, Baltimore, Md.
410-338-4514
villard@stsci.edu