The crossword solutions for the term MERCURY OR MARS are PLANET (6 letters), ORB (3 letters), DEITY (5 letters), and GOD (3 letters). Mercury and Mars are two of the eight planets in our Solar System. Mercury is the smallest PLANET and orbits closest to the Sun, while Mars is the fourth PLANET from the Sun and is known for its red hue. The ORB is the path that a PLANET follows around the Sun. In Roman mythology, Mercury was the messenger of the gods and the GOD of commerce, travel, and thievery, while Mars was the GOD of war. In Greek mythology, Mercury was known as Hermes and Mars was known as Ares.