| Ultra High Contrast (UHC) Filter |
A type of nebular filter that only allows light frequencies common to nebulae and galaxies through. |
| Umbriel |
A moon of Uranus was discovered by William Lassell on October 24, 1851. Umbriel is also designated as "Uranus II". Umbriel is the 'dusky melancholy sprite' in Alexander Pope's poem The Rape of the Lock. |
| Universal Time |
Mean solar time on the Prime Meridian. Also called Greenwich Mean Time. |
| Uranian |
Having to do with the planet Uranus. |
| Uranus |
Uranus is the seventh planet from the Sun. Uranus' diameter is 51,100 km and takes 84 years to orbit the Sun. Uranus is named after the Greek god of sky. Uranus was discovered on March 13th,1781 by Sir William Herschel, who reported it as a comet on April 26, 1781. |
| Ursa Major |
The constellation "The Big Bear" |
| Ursa Minor |
The constellation "The Little Bear" |
