|
 It is so cold on Neptune
that you would need skin thicker than a polar bear's to stay warm. Neptune and
Uranus are very much alike. They are both large gas planets that look like big blue-green balls in the
sky. Neptune has winds in its
atmosphere which blow at over 2000
kilometres per hour! This planet has
large, dark circles on its surface which
astronomers believe to be storms.
Neptune has two thick and two thin rings which surround it. Neptune also has
eight moons. Four of these moons
orbit the planet within the rings. One
of Neptune's moons, Triton, orbits the planet in a direction opposite that of
the seven other moons. Due to Pluto's unusual
elliptical shaped orbit, Neptune is
actually the farthest planet from the Sun for a 20 year period out of every 248
Earth years.
Facts:
- (1)
Neptune is the outermost of the four gas giants: Jupiter, Saturn, Uranus,
Neptune.
- (2)
Because of its distance from the Sun, Neptune's atmosphere is a frigid -225° C
(-373° F).
- (3) The
blue-green colour of the planet is due to the presence of methane in the
atmosphere.
(4) The atmosphere consists mostly of hydrogen, helium and methane.
- (5)
Until the Voyager encounter in 1989, the rings surrounding Neptune were
thought to be arcs.
(5) We now know that the rings completely circle the planet, but the thickness
of each ring varies along its
length.
|
Discoverer(s): |
Galle,
Challis, Adams, & Le Verrier (1846) |
|
Spacecraft Encounter(s): |
Voyager
2 |
|
Mean
Distance from the Sun: |
30.06
AU (4.497 billion km/2.794 billion mi) |
|
Length
of year: |
165
years |
|
Rotation period: |
16.11
hours |
|
Mean
orbital velocity: |
5.43
km/s (3.3 mi/s) |
|
Diameter: |
49,528
km/30,775 mi |
|
Inclination of axis: |
29.6° |
|
Number
of observed satellites: |
8 |
|
Comparisons with Earth: |
|
Diameter: |
3.883 x
Earth's |
|
Average
distance from Sun: |
30.06 x
Earth's |
|
Mass: |
17.14 x
Earth's |
|
Density: |
0.31 x
Earth's |
|
