Luna moth color is blue-green in the north and for the over-wintering generation in the central and southern states; second and third generation wing color has more of a yellow-green tint. Described and named "Phalena plumata caudata" by James Petiver in 1700, this was the first North American saturniid to be reported in the insect literature. The initial Latin name, which roughly translates to "brilliant, feather tail", was replaced when Carl Linnaeus described the species in 1758 in the tenth edition of Systema Naturae, and renamed it "Phalaena luna", later "Actias luna", with "luna" derived from Luna, the Roman moon goddess. The
Dynamics of the celestial spheres bodies are moved by angelic spirits, which govern and move them. He maintained, instead, that "celestial bodies are moved by their own natural inclinations similar to weight". Just as heavy bodies are naturally moved by their own weight, which is an intrinsic active principle, so the celestial bodies are naturally moved by a similar intrinsic principle. Since the heavens are spherical, the only motion that could be natural to them is rotation. Kilwardby's idea had been earlier held by another Oxford scholar, John Blund (c. 1175–1248). In two slightly different discussions, John Buridan (c.1295–1358) suggested that when God created the