|
 Uranus is one of the
smaller
gas giants in our
solar system, but it is
still large enough to hold 64 planets the size of Earth. Uranus tilts over so far on its
axis that it
rotates on its side. Because of this, its
poles are sometimes pointed almost directly at the
Sun. Uranus' atmosphere is made up of hydrogen, helium, and
methane. The temperature in the upper atmosphere is very cold. The cold methane
gas is what gives Uranus its blue-green colour. The rapid rotation of Uranus
causes winds up to 600 kilometres per hour to blow in its atmosphere. Uranus
has eleven known rings which contain dark,
boulder-sized particles. Uranus has at least 20
known moons. Some of these moons are less than 100 kilometres wide and black as
coal. One more moon may have been found by astronomers. Other scientists are
trying to confirm the discovery.
Facts:
|
Discoverer: |
Sir William Herschel (1781) |
|
Spacecraft Encounter(s): |
Voyager 2 (1986) |
|
Mean
distance from Sun: |
19.19
AU (2.871 billion km/1.784 billion mi) |
|
Length
of year: |
84.01
Earth years |
|
Rotation period: |
17.24
hours |
|
Mean
orbital velocity: |
6.81
km/s (4.2 m/s) |
|
Inclination of axis: |
97.92°
|
|
Diameter: |
51,118
km (31,765 mi) |
|
Number
of Observed Satellites: |
>20 |
Comparison
with earth:
|
Diameter: |
4.0 x
Earth's |
|
Mean
Distance from Sun: |
19.2 x
Earth's |
|
Mass: |
14.5 x
Earth's |
|
Density: |
0.22 x
Earth's |
Comparisons with Earth:
|
