I’d buy you a beer, but you won’t be legal until October 29, 5307

Alternate title: happy birthday, Neptune. You don't look a day older than three!

Tonight the planet Neptune completes its first trip around the sun since humans first discovered the gas giant planet.

Neptune is the only planet to have been discovered by mathematics. Le Verrier noticed irregularities in the motions of other planets, and from these perturbations calculated that there must be an eighth planet lurking out beyond Uranus.

Using (French astronomer Urbain) Le Verrier’s calculations, German astronomer Johann Galle at the Berlin Observatory located the new planet on Sept. 23, 1846.

Neptune's orbit is shaped roughly like an oval, with the planet taking about 165 years to complete a single circuit. The average distance between Neptune and the sun is nearly 2.8 billion miles (4.5 billion kilometers). That's roughly 30 times as far away as Earth.

Neptune’s orbit takes 60,190 days to complete a single rotation around the sun – a little less than 165 Earth years. Which means I’ll be 206 years old by the time Neptune turns two, which means that...well, I guess I won't be buying Neptune a beer for its 21st birthday on October 29, 5307.

But at least that's a Saturday, y'know, so Neptune won't have to worry about getting up for work the next day.