Category Archives: Uranus
Wrapped in an atmosphere tinted pale blue by high-altitude methane, Uranus has occasionally been observed to develop large storms in its frigid windy skies. NASA’s Voyager 2 saw a few small storm clouds spotting Uranus during its flyby in Jan. 1986, and more recently some large but short-lived storms were observed by Hubble and the W.M. Keck Observatory as the planet moved toward its equinox in 2007. Now, seven years after its equinox, swirling storms are once again blooming on Uranus — and Keck astronomers have caught them on camera (while preparing for terrestrial hurricanes to make landfall!)
Voyager 2 may have been the second of NASA’s twin exploration spacecraft but it launched first, 35 years ago today on August 20, 1977. 8 1/2 years later it became the first (and last!) spacecraft to visit the gas giant Uranus, the third largest planet in the Solar System.
This ghostly image was taken by a Chilean ground-based telescope in 2002. It shows the enigmatic gas giant Uranus in near-infrared light, 7 of its 27 known moons visible. (For a labeled version of this image noting the moons, click here.)
Seventh planet from the sun, Uranus’ year is 84 Earth-years long. Like the other gas giants, Uranus has rings – thirteen, at last count. What makes Uranus especially different among the planets is its unique axial tilt…the entire planet, rings and all, is tipped nearly horizontal along its orbital plane. It’s as if it were “lying down”.
More recently on August 17, 2007 the Hubble Space Telescope captured a photo of Uranus with its rings angled edge-on to Earth. This viewpoint is only possible once every 42 years.
Uranus is approximately 4 times larger than Earth in diameter.
Image: European Southern Observatory