Neptune was discovered by Johanne Galle on September 23rd, 1846. Working at the Berlin Observatory, Galle used the observatory’s nine inch refracting telescope to search for a possible eighth planet. Galle had been asked to search a particular spot in the sky by a French mathematician, Urbain Leverrier, where he’d calculated it to be. Through the eyepiece, Galle saw a tiny, faint blue dot – was it just another star? Galle and his assistant Heinrich d’Arrest opened up their book of star maps, something called, the Berliner Akademischen Sternkarte, (I think I said that right,) and found that his star was “not on the map!” The next night they found that the tiny dot had moved against the background of fixed stars - it was a wanderer, a planet. Neptune is still in our sky, over in the constellation Aquarius in the southeast after sunset tonight, and yes, even though our planet just passed it and it’s less than 2.7 billion miles away, you’ll still need a pretty good-sized telescope to see it.