 Dante implies that the light of the planets is a combination of light imparted by Divine will and the radiance of the blessed souls that inhabit the spheres.These planets are, however, entirely ethereal; they have light but no physical form and no geography.Ludovico Ariosto, in his epic Orlando Furioso (1513), jestingly sent his hero to a Moon where everything lost on Earth eventually turns up; but it was not until Galileo discovered (1609–1610) that the Moon had surface features, and that the other planets could, at least, be resolved into disks, that the concept that the planets were real physical bodies came to be taken seriously.