Mars, often referred to as the Red Planet on account of its distinctive coloration, is the fourth planet in the Solar System. It is a terrestrial (rocky) planet, the second largest of the system's four terrestrial planets after Earth. Mars has two known moons, Phobos and Deimos, both of which are small and irregularly shaped.
As the nearest planetary neighbor to Earth, Mars was perhaps inevitably the first planet to be colonized by humans, during the mid 21st Century. The planet went on to become the site of many colonies and military bases of the Three World Empire, the United Americas and other national and industrial organizations. Mars was one of the pillars in the creation of the Three World Empire and was also home to a few colonies established by Weyland Corp. Karen Sneddon took her apprenticeship with the Weyland-Yutani Corporation on Mars.
Mars is also home to the Valles Colony. Terraformed from 2032 to 2040 and established in 2040 by Weyland Corp, Valles had a population of 16,780,000 as of January 1st 2073. Valles Colony was established to exploit vast deposits of rare-earth metal. Valles has five main industries; Mining, Refining, Light and Heavy Manufacturing and five key resources; Niobium, Europium, Neodymium, Copper and Chromium.
Mars is home to the Leo Colony. Terraformed from 2032 to 2040 and established in 2041 by Weyland Corp, Leo had a population of 22,670,000 as of January 1st, 2073. Leo Colony is known for being the largest security sector (weapons and logistics development and manufacture) and atmosphere processing facilities in the systems. Leo has six main industries: Mining, Tourism, Security, Terraforming, Light and Heavy Manufacturing and four key resources; Cerium, Nickel, Tungsten and Neodymium.
- In Prometheus, the hologram of Peter Weyland was recorded inside a colony on Mars which, at the time of said recording, was still under construction.
- Aliens: Colonial Marines Technical Manual (mentioned only)
- Alien Resurrection (novel) (mentioned only)
- Alien: Out of the Shadows (mentioned only)
- Alien: Isolation (novel) (mentioned only)
- Aliens: Rescue
- Alien: Prototype (mentioned only)
- Aliens: Fireteam Elite (mentioned only)