This picture of Neptune was taken on August 20, 1989 by Voyager 2. In the center of the image, the Great Dark Spot can be seen. The latitude of the planet Neptune is 22 degrees south and circuits every 18.3 hours. The east and the south of the Great Dark Spot change their appearances constantly in four hours.
The internal structure of Neptune can be inferred from the planet's radius, period of rotation, mass, and shape of its gravitational field and the behavior of hydrogen, helium, and water at high pressure. The picture shows a cut-away view of Neptune composed of an outer envelope of molecular hydrogen, helium and methane. Below this region Neptune is composed of a layer rich in water, methane, ammonia, and other elements with high temperatures and pressures. Ice and rock constitutes the core of Neptune.
This picture gives a nearly true picture of Neptune taken by the Hubble Space Telescope's (HST) Wide Field Planetary Camera (WFPC), with a picture of Triton taken with the HST's Faint Object Camera. Even though, the image of Triton is faint but it clearly shows a bright equatorial region. In the lower left, the south pole is clearly visible. Near the bottom of the image a bright cloud feature can also be seen. It can be seen at 30S and 60S latitude. Another bright cloud can also be seen at 30N latitude in the northern hemisphere.
The dynamic nature of Neptune is clearly visible from the fact that the second smaller ...
In One feature that is conspicuous by its absence is the storm system known as the Great Dark Spot.
HST Observes High Altitude Clouds
These three pictures were taken on October 10, October 18 and November 2, 1994 when Neptune was only 4.5 billion kilometers from Earth. The pictures further proved the dynamic nature of the planet as the difference in the temperature between Neptune's Building on Voyager's initial discoveries, Hubble has revealed that Neptune has a remarkably dynamic atmosphere that changes over just a few days. Only in few days, the temperature difference between Neptune's strong internal heat source and its frigid cloud tops were-162 Celcius or -260 Fahrenheit which might be the causes that trigger instabilities in the atmosphere and result in large-scale weather changes. The high altitude methane ice-crystals can be seen in pink.
New Dark Spot
After the images in June 1994, which showed the disappearance of the Great Dark Spot, on November 2 a new spot, appeared near the limb of the planet. The new spot has high altitude clouds along its edge, resultant of gasses that have been pushed to higher altitudes where they cool to form methane ice crystal clouds. The dark spot may be a zone of clear gas that is a porthole to a cloud deck lower in the atmosphere.
Bands of sunlit cirrus-like clouds can be seen in this image of Neptune's northern hemisphere. 35 miles mellow, shadows are cast on the blue cloud deck. The width of the white streaky clouds ranges from 48 to 160 kilometers (30 to 100 miles) and extend over thousands of miles.
The picture taken by Voyager 2 has been edited