Uranus
Uranus is the seventh planet from the Sun and is the third largest in
the solar system. It was discovered by William Herschel in 1781.
It has an equatorial diameter of 51,800 kilometers (32,190 miles)
and orbits the Sun once every 84.01 Earth years. It has a mean
distance from the Sun of 2.87 billion kilometers (1.78 billion miles).
The length of a day on Uranus is 17 hours 14 minutes. Uranus has at
least 15 moons. The two largest moons, Titania and Oberon, were
discovered by William Herschel in 1787.
The atmosphere of Uranus is composed of 83% hydrogen, 15% helium,
2% methane and small amounts of acetylene and other hydrocarbons.
Methane in the upper atmosphere absorbs red light, giving Uranus its
blue-green color. The atmosphere is arranged into clouds running at
constant latitudes, similar to the orientation of the more vivid
latitudinal bands seen on Jupiter and Saturn. Winds at mid-latitudes
on Uranus blow in the direction of the planet's rotation. These winds
blow at velocities of 40 to 160 meters per second (90 to 360 miles per
hour). Radio science experiments found winds of about 100 meters per
second blowing in the opposite direction at the equator.
Sun
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Uranus Statistics
Discovered by William Herschel
Date of discovery 1781
Mass (kg) 8.686e+25
Mass (Earth = 1) 1.4535e+01
Equatorial radius (km) 25,559
Equatorial radius (Earth = 1) 4.0074
Mean density (gm/cm^3) 1.29
Mean distance from the Sun (km) 2,870,990,000
Mean distance from the Sun (Earth = 1) 19.1914
Rotational period (hours) -17.9
Orbital period (years) 84.01
Mean orbital velocity (km/sec) 6.81
Orbital eccentricity 0.0461
Tilt of axis (degrees) 97.86
Orbital inclination (degrees) 0.774
Equatorial surface gravity (m/sec^2) 7.77
Equatorial escape velocity (km/sec) 21.30
Visual geometric albedo 0.51
Magnitude (Vo) 5.52
Mean cloud temperature -193°C
Atmospheric pressure (bars) 1.2
Atmospheric composition
83%
15%
2%