Neptune - Voyager 2 - Image of Neptune obtained by the Voyager 2 probe on...

Neptune - Voyager 2 - Image of Neptune obtained by the Voyager 2 probe on August 14, 1989 at 14.8 million km from the planet. Neptune has an equatorial diameter of about 49,000 kilometres. Its blue color is due to the abundance of methane in its atmosphere. On this photo, on the right, the Great Dark Spot, which is the size of the Earth where winds are blowing at 300 m/s. This spot has now disappeared but other dark spots have been detected since then. This contrast enhanced color photograph of Neptune was produced from images taken through the orange, green, and violet filters of the narrow angle camera. As Voyager 2 approaches Neptune, rapidly increasing image resolution is revealing striking new details in the planet's atmosphere, and this picture shows features as small as a few hundred kilometers in extent. Bright, wispy “” cirrus - type”” clouds are seen overlying the Great Dark Spot (GDS) at its southern (lower) margin and over its northwest (upper left) boundary. This is the first evidence that the GDS lies lower in the atmosphere than these bright clouds, which have remained in its vicinity for several months. Increasing detail in global banding, and the south polar can also be seen. A smaller dark spot at high southern latitudes is dimly visible near the limb at lower left