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
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.