Wednesday, 19 February 2020

georgium sidus

Writing for Æon magazine, historian of astronomy Stephen Case guides us on a fascinating and convoluted process on how the naming conventions of the planets came to be through the lens of the discovery of what we now know as Uranus by William Herschel in March of 1781–the first new planet since antiquity and in (relatively) quick succession what we now call Neptune by Urbain Le Verrier. Whereas Uranus had been marauding through the night sky unrecognised for the planet it is and mistook for a star of the firmament and initially reported as a comet and left to the discoverer’s son to champion, Neptune existence was mathematically derived and then verified through observation, the only standing precedent for naming rights came from the Galilean moons of Jupiter named the Stars of the Medici after Galileo’s patrons.
To the extent that one bothered to differentiate the satellites at all, co-discoverer Simon Marius, astronomer royal of the Margraviate of Ansbach, suggested that they be named after their planetary analogues: the Mercury of Jupiter and so on—before ultimately being named for paramours of Zeus. The elder Herschel had named his discovery after George III, somewhat of a consolation for loosing the American colonies, a decision his son and intellectual heir regretted but was adamantly against the counter suggestion by Le Verrier that they name the planets after themselves. The younger Herschel found a way out of this impasse by returning to the subject of naming satellites—specifically for those orbiting Saturn, a couple of which he had discovered himself. Mythologically awkward to name the moons after family members of the Titan who deposed his father—Ouranos, Uranus incidentally—and devoured his children, Herschel proposed naming the moons after peer giants and giantesses. The matter was settled and extended to keeping the planets named after Greco-Roman gods—rallied by choosing to call a newly isolated element uranium after the ancient sky deity. By dint of the sheer number of Cronian satellites, giants from other pantheons are admitted as well. Though arguably installing an Anglo-American hegemony among the stars, the International Astronomical Union while not neutral does promote inclusion in its work. Though eschewing the honour himself, the Hawaiian term (whose own legends are enjoying more representation) for Uranus is Hele’ekala, a loan word for Herschel.