Neptune is the 8th planet from
the Sun and is 4.5 billion kilometers (2.8 billion miles) away
from it. There are some times when Pluto's highly
eccentric orbit takes it within Neptune's orbit making Neptune
the 9th planet from the Sun. (Note: this assumes
that Pluto is a planet, which is technically incorrect due to
Pluto's recent demotion to dwarf planet status). It takes almost
165 years for Neptune to travel around the Sun.
Neptune has a magnetic field which is 27 times more powerful
than Earth's.
Neptune is believed to have an Earth sized solid core surrounded
by a thick atmosphere consisting of hydrogen, helium, and
methane. It is the methane that gives Neptune its blue
color. Extremely violent winds blow on Neptune that are 3
times strong as those on Jupiter. Neptune has 6 rings of
varying thickness. NASA scientists have located 13 moons
using pictures taken by visiting spacecraft.
Triton is the largest of Neptune's moons and is the coldest body
in the solar system at an average temperature of -235°C
(-391°F). Icy geysers have been observed on Triton.
| Mass (kg)
| 1.02 x 1026
|
| Diameter (km)
| 49528
|
| Mean density (kg/m3)
| 1640
|
| Escape velocity (m/s)
| 23300
|
| Average distance from Sun
| 30.07 AU (4,498,252,900 km)
|
| Rotation period (length of day in Earth days)
| 0.67 (19.1 hours)
|
| Revolution period (length of year in Earth days)
| 60,190 (164.8 Earth years)
|
| Obliquity (tilt of axis degrees)
| 29.6
|
| Orbit inclination (degrees)
| 1.77
|
| Orbit eccentricity (deviation from circular)
| 0.009
|
| Mean temperature (K)
| 48
|
| Visual geometric albedo (reflectivity)
| 0.51
|
| Atmospheric components
| 74% hydrogen,
25% helium,
1% methane (at depth)
|
| Rings
| Rings are narrow, and contain
concentrations of particles
called ring arcs.
|
|
Image Neptune
Photograph of Neptune
and Triton
Neptune Clouds |
