400 years ago today, a great arms race was underway in the scientific community: using the newly developed technology afforded by the telescope, astronomers and natural scientists stayed up night after night training their new instruments on the sky. Few were as prolific or as careful (or talented) as Galileo Galilei who 400 years ago today, 28 December 1612 first saw the planet Neptune through a telescope. Galileo noted the object but failed to recognize its significance, and Neptune disappeared for another 234 years, when it was predicted by French astronomer Urbain LeVerrier. A second arms race began when English, French and German scientists all raced to find the planet predicted by the perturbations in Uranus’ orbit. The prediction was soon confirmed by German astronomer Johann Gottfried Galle just one year after he finished his Ph.d dissertation which he had sent to LeVerrier for comments. Galle found Neptune first, though James Challis had both spotted it and noted it but failed to recognize it as a planet due to using outdated star maps. A minor battle then ensued when LeVerrier suggested the name Leverrier for the new planet-and had English astronomers immediately insist that the recently discovered Uranus be named Herschel after its discoverer, the Anglo German astonomer William Herschel, who for his part wanted to call Uranus after his patron King George III of England. Galle first proposed Janus (the Roman two-faced god) and Challis proposed Oceanus. Ultimately consensus was found by continuing with the theme of naming planets after Greek and Roman gods, as the west had done since antiquity, and the planet was named Neptune. Irregularities in Neptune’s orbit led to a third race to discover any satellites that might be orbiting, and soon enough Neptune’s first moon was discovered.
Image of Neptune and the Great Dark Spot courtesy NASA, in the public domain.