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Observing the Sky Solar System Satellites Navy Research Resources

Solar System: Outer Planets - Neptune

The Windy Planet

Like the other Jovian planets, Neptune has rings, it generates more energy than it receives from the Sun, and its atmosphere is constantly changing due to temperature variations. Neptune, however, is home to the strongest winds in the solar system—with some that travel at 1,243 miles (2,000 km) per hour!

Neptune has been visited by only one spacecraft, the Voyager 2, in 1989. During that visit Voyager took lots of pictures of Neptune and its most prominent feature—the Great Dark Spot—which raced around Neptune’s southern hemisphere at 700 miles (1,267 km) per hour. Neptune’s atmosphere changes so rapidly that in 1994 when the Hubble Space Telescope photographed it, the Great Dark Spot had disappeared, but a new spot was forming in the northern hemisphere.

The orbit of Neptune’s neighbor, Pluto, is so eccentric, that sometimes Pluto crosses inside the orbit of Neptune. From 1979 to 1999, Neptune was the most distant planet in the solar system.

Neptune can be seen with binoculars if you know where to look, but a telescope will ensure a better view.

Photo of Neptune
Courtesy of NASA JPL