Mars is the fourth planet in the solar system. Mars is a human-colonized planet. By 2155, terraformation was already underway, and the atmosphere was breathable. At that time, there was a so-called verteron field, a weapon that was able to destroy asteroids or comets that would threaten the Earth or its colonies in the solar system. However, the first official colony was established on Mars long before that, in 2103. The later-built Utopia Planitia colony is designed by the Starfleet spacecraft, and directly above the colony, the key Starfleet building docks are in orbit.