Gods in the Roman pantheon have, like their Greek counterparts, left their mark on the English language. They pop up most obviously in the names of celestial bodies and in the calendar. Six of the planets - Mercury, Venus, Mars, Jupiter, Saturn and Neptune - are Roman gods, as are two of the dwarf planets - Ceres and Pluto. In addition, Roman gods appear as the names of some of the months, with January, March and June, (and...