Neptune

Little was known about Neptune ,which was discovered in 1846, until the Voyager 2 encounter in 1989. It has a similar composition to Uranus and is close in mass to Uranus. Its thick atmosphere made of hydrogen, helium, and some methane and ammonia, gives it a bluish color.
DISCOVERY
On August 25, 1989, the voyager discovered Neptune, but only after traveling 12 years at an average velocity of 19 kilometers a second (about 42 miles an hour). The Voyager 2 observed Neptune almost continuously from June to October 1989. This discovery though, gives us just about all the info about Neptune.
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