Mars, the 4th planet from the Sun, is colder than the South Pole! How? It is all because of it’s distance from the Sun. Mars is over 141 million miles away from the Sun, while Earth is about 91 million miles away from the Sun. Mars is way farther away from the Sun than Earth! Since Mars is so far away, the Sun’s heat can’t really reach it. That makes this “red planet” icy cold!