Voyager 2
August 25, 1989


Neptune, with Triton in the background

Neptune, with Triton in the background


Voyager 2 is the first -- and as of 2002, only -- spacecraft to observe Neptune. Twelve years after leaving Earth, Voyager 2 makes its closest approach to any planet since starting its journey, flying about 4,950 kilometers (3,000 miles) above Neptune's north pole. It discovers that Neptune has the strongest winds of any planet encountered, even though it receives the least solar energy.

Voyager 2 also passes about 40,000 kilometers (25,000 miles) from Neptune's largest moon, Triton, the last solid body the spacecraft will have an opportunity to study. With a temperature around -235 degrees Celsius (-390 degrees Fahrenheit), it is the coldest body ever visited. Even so, geysers erupt on the moon's polar cap of frozen nitrogen and methane.

After Triton, Voyager 2 heads downward out of the plane of the planets. Like Voyager 1, it begins a journey to the edge of the solar system and beyond. As of 2002, it continues to send back data from its location well past Pluto.

See also: Voyager home page

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