I’ve looked this up, but not necessarily sure the internet has the right answer. Why are the planets in our solar system named after Roman gods, except Earth, and why is only one of the nine planets a female? Interestingly, Mercury, according the internet "serves as the guide of souls to the underworld” and Pluto, which was, but is no longer a planet, was named after the Roman God of the underworld.

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    $\begingroup$ The five naked-eye-visible planets (Mercury, Venus, Mars, Jupiter and Saturn) were named long before anyone realised that they were the same type of object as the Earth. The other planets were discovered later, but were named after Roman gods to match the names of the already-known ones (although there there was apparently a shortlived plan to name Uranus after George III) $\endgroup$
    – JayFor
    Commented Nov 25, 2023 at 20:47
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    $\begingroup$ This is a question about Mythology & Folklore. not astronomy. But Terra was a goddess of the Roman pantheon. It just happens that the English word for Earth comes from the germanic, not from Latin. $\endgroup$
    – James K
    Commented Nov 25, 2023 at 22:53
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    $\begingroup$ The alternative name of Earth is Terra which is a Latin name as well as a primeval Roman goddess. But we usually stick with Earth. $\endgroup$ Commented Nov 26, 2023 at 4:33
  • $\begingroup$ Genesis 1:1 - in the beginning God created the heaven and the earth…. In the Hebrew the word earth is "אֶרֶץ" (eretz, sometimes pronounced earth). This predates the Romans. $\endgroup$
    – eshaya
    Commented Nov 26, 2023 at 19:32
  • $\begingroup$ @eshaya The word "earth" derives eventually from the proto-indo-european stem "er-" or "erd", meaning ground or soil, so there are cognates across a huge swath of the planet. The english word derives most directly from proto-germanic "ertho". We live on the planet Dirt. $\endgroup$ Commented Nov 29, 2023 at 15:39

1 Answer 1


There are two primary reasons why the planets were named after Roman Gods.

  1. Language - the early astronomers in Europe wrote in Latin, and Latin was the language of the Roman Empire. So they ended up naming the planets after Roman gods
  2. Religion - Ancient Romans were heavily devoted towards gods and religion and they thought that the gods and goddesses controlled every aspect of life, even creation of these celestial objects.

Even in modern times, the IAU has adopted this tradition in its rules for naming celestial objects in the solar system:

  • Uranus and Neptune were discovered after the telescope was invented in the early 1600s and the discoverers wanted to name them after them or some king. Ultimately, they settled with naming them after gods. Please check the full history here.

  • For recently discovered natural satellites, they are first given a "provisional" or temporary name while additional observations are made to confirm their existence. This temporary name (usually consisting of the year of discovery and some number indicating the order of discovery in that year) is assigned by an organization called the Central Bureau for Astronomical Telegrams (CBAT). Once the existence of the object is confirmed (and its orbit determined), it is given a final name. The name is suggested by the discoverer(s), but the tradition is however followed.


  1. https://www.nasa.gov/general/how-do-planets-get-their-names-we-asked-a-nasa-scientist-episode-45/
  2. https://starchild.gsfc.nasa.gov/docs/StarChild/questions/question48.html

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