8.10: Planet Uranus
Uranus was the first planet found with a telescope. Uranus was discovered by Sir William Herschel in 1781, even though others might have recorded Uranus prior to Herschel and not realized what they were seeing. Uranus is often referred to as Neptune’s twin, because of similarities in their sizes, colors, and other characteristics.
Uranus rotates on its side. It is believed that this odd rotation is due to a collision with its moon Miranda. The planet shows little atmospheric activity, and actually looks like a green billiard ball. If Uranus has a core at all, it is a very small rocky core.
In its atmosphere, Uranus has more water, ammonia, and methane ices in its atmosphere than Jupiter and Saturn; so it is often referred to as an Ice Giant . It is the coldest planet in the solar system. Like Jupiter and Saturn, Uranus also exhibits aurora activity. The planet has 13 rings, composed of dark particles made of dust to less than a meter in diameter. Uranus has 27 known moons (as of August 2014); not as many as Jupiter or Saturn, but definitely its own system of worlds which orbit the planet.
Uranus at a Glance
Characteristics to Compare
Atmosphere
- Hydrogen (H 2 ), Helium (H e ), Methane (CH 4 ), Ammonia (NH 3 ), Water (H 2 O)
Rotation
- Short rotation — 17. 3 hours retrograde (backwards)
Revolution
- Long revolution — 84. 01 years
Rings
-
An intricate system of rings:
- 13 rings total; first 9 found via airborne telescope
Magnetic Field
- Yes, tilted about 45 o . Reason for tilt unknown
Uranus Satellite of Distinction — Chevron; is this possible tectonic activity? Probably collided with Uranus.