the summer of 1989, NASA's Voyager 2 became the first spacecraft
to observe the planet Neptune, its final planetary target.
Passing about 4,950 kilometers (3,000 miles) above Neptune's
north pole, Voyager 2 made its closest approach to any planet
12 years after leaving Earth in 1977. Five hours later, Voyager
2 passed 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.
a fact sheet on Neptune science summary, click here.
on the image for a larger view: