Today, August 25th, marks the 20th anniversary of the arrival of Voyager 2 at Neptune. In 1989 this automated probe completed a 12 year voyage to our solar system’s most distant planet, after visiting Jupiter, Saturn and Uranus. It passed less than 5,000 km above Neptune’s north pole, and a few hours later passed the large moon Triton. The images that were returned gave us our first detailed look at this giant planet and its satellite system.
Today, Voyager 2 and its companion Voyager 1 are both still operating well and are 13 and 16 billion km away, respectively. They are in communication with Earth on a weekly basis, with radio signals taking over a day to travel the great distance. In the twenty years that have passed since Voyager’s visit to Neptune, no other probe has been to the planet. Voyager 2 remains our sole emissary to Neptune.
