One of the most interesting planets in the Solar System has the dubious honor of being given an awkward name. There are dozens of cheeky bon mots surrounding the name Uranus. I came across a headline that was possibly written with this uncomfortable brand of bathroom humor in mind. “Scientists Have Discovered a Ring of Debris around Uranus”.
The peculiarly tilted blue Planet was named after the mythological Greek God of the sky, Ouranos, not an anatomic feature of the human body. The large, astronomical body orbits so far away from Earth, that we are likely to discover many more interesting features about it in the future.
On March 10, 1977, two teams of astronomers made a major discovery about Uranus. Observers at the Kuiper Airborn Observatory (a modified jet transport aircraft based in Sunnyvale, California) and scientists at the Perth Observatory in Australia had prepared to observe the transit of Uranus in front of the star SAO 158687.
As Uranus slowly began to obscure the view of the star, observers noticed that the light seemed to briefly “blink out” several times before the planet finally obscured the star (occulted). The Australians were baffled about the phenomenon. Meantime, the flying observatory in California had a clearer view of the transit so the astronomers were more quickly able to understand the implications of the “blinking” of the star.
According to NASA, the team of James Elliot, Edward Dunham, and Douglas Mink, deduced that Uranus was encircled by five narrow rings. Years later, following observation of images from the Voyager Space Probe and the Hubble Space Telescope, scientists now say that Uranus is encircled by 13 distinct rings. Unlike the water ice and dust rings of Saturn and Jupiter, the rings around Uranus are thinner and somewhat more complicated. In addition to the 13 rings, there is also a beautiful partial ring or arc. All of these are accompanied by 27 moons, at last count.
Dr. David Williams of NASA says that the majority of Uranus’ rings are not completely circular, nor do most of them orbit in the exact equatorial plane. The narrow rings are as small as a few kilometres across and there is little or no “dust” between them, as is the case with Saturn’s rings.
Astronomers speculate that the stability and sharpness of the rings is due to the small “shepherding moons” that may be in the process of clearing debris out of their orbital paths. For instance, the Voyager 2 craft photographed two shepherd moons in conjunction with the brightest ring “Epsilon”. One moon orbits just inside of Epsilon and the other one orbits just outside of it.
NASA scientists believe that Uranus’ rings are relatively young, possibly less than 600,000,000 years in age. They hypothesize that some pre-existant shepherd moons were shattered by the immense gravity of Uranus. The large pieces scattered and repeatedly collided with one another. Over the years and with numerous collisions the chunks became smaller.
An interesting historical fact about the ring system of Uranus, is that it was the second ring system discovered after that of Saturn.
The Blue Jay of Happiness ponders this insightful quote from John F. Kennedy: “I am sorry to say that there is too much point to the wisecrack that life is extinct on other planets because their scientists were more advanced than ours.”