In English the word "planet" and the planets themselves are gender neutral. "Venus" may have originally been the name of a female god, but the planet itself is it/it:

> Venus is the second planet from the Sun. It is a rocky planet with a mass and size narrowly second in the Solar System to Earth

English doesn't sex nouns, so it will probably vary from language to language

In Portuguese the word 'planet' is grammatically male ("o planeta...").

They are all grammatically female in French, even when named after male gods.