Interesting Neptune Facts
Mass 102.43 x 1024
Volume 6,254 x 1010km3
Equatorial Radius 24,766 km
Roational Period 16.11 hours
Surface Gravity 11.00 m/s2

 

 

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Another one of the gas giants that orbit the sun 2.8 billion miles (4.5 billion km) away is Neptune. This large planet is the fourth largest in this solar system and is more than 17 times larger than earth. Neptune was officially discovered by Johann Gottfried in 1846 after the planet's mass and location were already calculated by John Couch Adams and Urbain Leverrier. They had managed to calculate the mass and location of Neptune because of the gravitational effect Neptune has on Uranus.

Neptune, like the other Gas giants consist of methane, ammonia, water, helium, and hydrogen. The methane gives it a light blue color similar to Uranus. The atmosphere on Neptune consists mainly of layers of ammonia, ammonium hydrosulfide, and probably water ice. The most noticable are the methane ice clouds.

The winds on Neptune are likely to be the most strongest on all planets because the wind speeds have been measured at over 1,200 miles (2,000 km) per hour.

The existence of a great dark spot that was located in the same latitude line as Jupiter's Great Red Storm proves how fast the winds blow. The Great Dark Spot on Neptune was probably a great storm system spinning counter-clockwise.

When Voyager 2 flew by Neptune, it had measured the winds in the Great Dark Spot at over 730 miles (325 meters per second) per hour. There has also been another smaller dark spot called DS2 found on Neptune.

However, when the Hubble telescope focused in on Neptune on July 27, 1994, the Great Dark Spot as well as DS2 had disappeared and scientists till this day are not exactly sure why it has disappeared. They had assumed it would stay there for a much longer period of time like the red spot on Jupiter that has been there for centuries.

A Picture of the high clouds of Neptune

These clouds were observed at a latitude of 29 degrees north near Neptune's east terminator.  The linear cloud forms are stretched approximately along lines of constant latitude and the sun is toward the lower left. The bright sides of the clouds which face the sun are brighter than the surrounding cloud deck because they are more directly exposed to the sun.  Cloud heights appear to be of the order of 50 kilometers (31 miles).
A close-up view of the Great Dark Spot

This image shows feathery white clouds that overlie the boundary of the dark and light blue regions.The pinwheel (spiral) structure of both the dark boundary and the white cirrus suggest a storm system rotating counterclockwise.
A picture of Neptune' Great Dark Spot

Three of the four main features are visible in this image.   The Great Dark Spot with its bright white companion is slightly to the left of center. The small bright Scooter is below and to the left, and the second dark spot with its bright core is below the Scooter. Strong eastward winds -- up to 400 mph -- cause the second dark spot to overtake and pass the larger one every five days.

Evidence that the Great Dark Spot has Disappeared

It is believed that the Great Dark Spot has disappeared because in these two pictures, taken by the Hubble Space Telescope, it does not show up. The Great Dark Spot is enormous and would normally show up, but it doesn't in these recent photographs. It has been concluded that the Great Dark Spot has disappeared.

The magnetic field on Neptune is also similar to Uranus by the fact that the magnetic axis is tilted 47° away from Neptune's rotational axis. It is believed that the magnetic field results from the conductive water caused by extreme pressure in Neptune's interior. Scientists also discovered rings on Neptune just as they had on Uranus. They had discovered them through an occultation of a star in 1984.

SATELLITES

There has been eight satellites discovered that orbit around Neptune. They are:

The sizes of the satellites range from 30 to 250 miles (50-400km) in diameter and of them, Triton is the largest. Triton has a diameter of 1,680 miles (2,700km) and is dense compared to the other moons in the solar system. Triton is composed of rock, silicates and solid water. The terrain on Triton resembles that of a cantaloupe with ridges and pits/depressions. There is also a very thin atmospheric layer of nitrogen and methane found on Triton, including methane and nitrogen ice caps.

There is also evidence that organic compounds exist on Triton because there appears to be geysers that spew out a dark substance to almost 5 miles high. The dark substance is believed to be a result of ultraviolet rays acting on methane and nitrogen to produce organic compounds. Another oddity of Triton is the fact that it orbits Neptune clockwise while all the other moons around Neptune orbit counterclockwise.

A close-up view of Triton's

Voyager 2 obtained this high-resolution color image of Neptune's large satellite Triton during its close flyby on Aug. 25, 1989. The large south polar cap at the bottom of the image is highly reflective and slightly pink in color; it may consist of a slowly evaporating layer of nitrogen ice.   From the ragged edge of the polar cap northward the satellite's face is generally darker and redder in color.  This coloring may be produced by the action of ultraviolet light and magnetospheric radiation upon methane in the atmosphere and surface.   Running across this darker region, approximately parallel to the edge of the polar cap, is a band of brighter white material that is almost bluish in color.

Another view of Triton's surface

This is a computer-gnerated perspective rendering of one of the caldera-like depressions on Triton, as it would appear if viewed from the northeast.   The topography was vertically exaggerated 20 times in producing this perspective view. Actual relief in the region has a maximum range of about 1 km (3,000 feet) in the 13 km (8-mile) diameter impact crater visible in the center of the image. The caldera floor, approximately 200 km (120 miles) in diameter, is extremely flat and probably was formed by the volcanic eruption of ice lavas of very low viscosity.

Picture of Proteus This image of Neptune's satellite 1989N1 was obtained on Aug. 25, 1989 from a range of 146,000 kilometers (91,000 miles).  The satellite, seen here about half-illuminated, has an average radius of some 200 kilometers (120 miles).   

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