Pluto’s Very Long Year

Pluto was discovered by Clyde Tombaugh in 1930, but it still has not completed even one full trip around the Sun since its discovery. A year on this dwarf planet lasts about 248 Earth years—almost two and a half centuries.

For comparison, Neptune takes about 165 years to orbit the Sun, Uranus takes 84 years, and Earth takes only 365 days.

Pluto will not return near the spot in its orbit where it was discovered until 2178. That means no person alive today will see the end of its first full “year” observed by humanity.