While watching the movie The Martian, a question arose regarding the name Ares:
Greek Gods were metaphrased into Latin when Romans took over. Ares (from the Greek Άρης) was now named Mars, and so on. And, as such, NASA uses the name Ares for their mission to Mars.
They also have a spacecraft named Hermes, an import of Ερμής. By this convention, shouldn't it be Hares then instead of Ares, since both start with a vowel, followed by a consonant (character "r")?
'A' might be an exception or something, yet, I remembered Hagia Sophia (in Constantinopolis), from the greek Αγιά Σοφία. This follows the same convention as Hermes, rather than that of Ares. Similarly, we have the name Hades.
Why is there variation in this convention?