All the planets names are from Roman mythology, not Greek.
Greek
The Hebrew name is Aharon, which appears as Aaron in Greek, since that language did not allow an intervocalic h. Greek is the language from which most of the English forms of Biblical names derive.
Zeta is the sixth letter of the Greek alphabet and has a value of 7 in the Greek numerals system. The names of the letter Z in the UK "Zed" and "Zee" both derive from the word Zeta.
Well many words derive from the gods' names, such as volcano from the roman god Vulcan, and many words derive from the Greek muses (eg. museum etc.). Also, my grandma always used to say 'By Jove' when we were in trouble, Jove being the Roman for Zeus.
Scientific names are usually in Latin or Greek. These languages are used in taxonomy to ensure that species names are universal and consistent across different languages and countries.
From Greek, meaning painting with light
Greek, 'sappheiros' - 'Blue Stone'.
persona
It comes from the Greek word, kathedra.
Earth (Gaia) is the only planet whose English name does not derive from Greek/Roman mythology. The name derives from Old English and Germanic. There are, of course, many other names for our planet in other languages.
The word legend has a Latin origin. Myth and mythology derive from Greek.