• Question: who named the planets and how long ago did they name them

    Asked by annelouise372 to Amy, Drew, Julia, Kimberley, Sara on 21 Jun 2011. This question was also asked by leona633.
    • Photo: Amy MacQueen

      Amy MacQueen answered on 17 Jun 2011:

      Hey annelouise!

      I think they were all named very long ago by early stargazers — the first astronomers to focus attention on the sun, the moon, and the visible planets Mercury(in Greek-Ερμης), Venus(Αφροδιτη), Mars(Αρης), Jupiter(Διας), and Saturn(Κρονος).They believed that each of these celestial bodies influenced a particular day of the week. Greeks and Romans gave the names of their gods to individual planets (with the notable exception of Earth).

      The Greeks and Romans matched planetary attributes with particular deities and named the known planets accordingly. Tiny Mercury was named after the fleet-footed messenger to the gods, probably because it moves so quickly across the sky; Venus, the brightest planet visible to the unaided eye, was named for the goddess of love and beauty. Jupiter, more than twice as massive as all the other planets combined, earned the name of the superior god. All of the them, gods of the ancients Greeks first and then Romans too.

      So that’s how they got their names and it was a long time ago! 🙂

    • Photo: Sara Imari Walker

      Sara Imari Walker answered on 21 Jun 2011:

      Hi annelouise, and leona! As Amy has nicely outlined, the ancients named the planets – where “planet” was meant to denote “wandering star”. That’s because they didn’t know they were whole planets! They just thought they were very special stars. With our naked eye we can only see five planets clearly: mercury, venus, mars, jupiter, and saturn. Those were the wandering stars of the ancient greeks and are known as the classical planets.

      Uranus and Neptune weren’t discovered until much much later! Uranus was not discovered in 1781, when Sir William Herschel announced its discovery. Can you imagine discovery of a whole new planet when only five had been known for thousands of years!!! How did Herschel make the discovery? Well with a telescope!! They were newly invented at the time.

      Neptune is another interesting story. Uranus actually has a wobbly orbit which led mathematicians to predict that an unknown planet was perturbing its orbit. Viola! Neptune was discovered in 1846 (turns out the calculations were wrong but they found a planet anyways!).

      Presumably Uranus and Neptune were named such to keep in theme with the ancient Greek naming scheme. Nowadays any body in the Solar System which gets a name is strictly enforced by the International Astronomical Union. Contrary to popular thought if you discover something like a new moon on one of the outer planets you can’t name it just anything. For example, I have a friend who discovered a moon of Uranus – he had to name it after a Shakespearean character!! Apparently that is the theme for moons of Uranus.

      Fun question!