Happy Belated, Dearest Neptune!

June 12 was Neptune's birthday. I was going to write about it. But I forgot. So here we go.

Neptune, the eighth planet from our Sun, takes 164.8 Earth years to rotate around the Sun. Exactly 164.8 years ago Neptune was discovered. So really, it's been a year since Neptune made its planetary debut.

The first person to 'notice' Neptune was Galileo on December 28, 1612, as a faint star. The (apparent) reason for Galileo's mistaking of the planet for a star was that Neptune had just reached 'retrograde', an effect that is caused when Earth's orbit takes it past an outer planet. What that means for the Earthbound observer is that the planet will seem to switch directions.

Since planets (Greek for 'wandering star') move differently from stars, which stay in a fixed place each night, they can be noticed easily. Retrograde, in its early stages, causes the planet to appear fixed, like a star. Thus, Galileo doesn't receive credit for Neptune's discovery.

Skip over a bit less than 250 years. It's 18forty-PARTY-six, and people were partying. In their weird 19th century way of partying. Tally-ho. And when people weren't partying, they were doing science.

Anyways, Johan Galle discovered Neptune at the Berlin Observatory on the night of September 23/24 after receiving a letter earlier that day from French mathematician Urbain Le Verrier telling of his prediction of a planet just beyond Uranus. He discovered just one degree from Le Verrier's predicted location. People got very angry.

Englishman John Couch Adams claimed he also predicted where Neptune was. This was no lie, he really had. Cambridge University astronomer James Challis had already searched for Neptune and found it in August 1846. The problem? He didn't identify it. Quoting Challis: "I have been greatly mortified to find that my observations would have shewn me the planet in the early part of August if I had only discussed them."

In the end, Galle and Le Verrier got there planet and... ate it, too. They didn't, actually. Unless someone made them a cake with Neptune drawn on it with icing. Then that would be another matter.

For anyone who has a telescope (as Neptune is not visible with the naked eye), in the next following weeks you can see Neptune exactly as Johann Galle saw it in party-crazed 1846.

A quick note. Although you'd think Neptune's one-year anniversary should have been September, there are some calculations that I don't completely understand that explain why it's in June. I don't want to misguide you lot, so I'll leave that for you if you care.

So that is the story of the great planet Neptune. Deceit, lies, Germans, publishing rights. Sounds like a French tragedy to me.

Feo.