A Complete History of the Earth's Sky

Abstract — v1

What could be seen from the ground at nineteen moments in Earth's history: the color of the sky, straight up and at the horizon, at the equator and the poles, at noon and at dusk, reconstructed with a spectral radiative-transfer model; and the Sun, Moon, planets, stars and everything else above it, from the molten newborn Moon to a sky full of satellites.