Mass Effect: After Armageddon
Mars is the fourth planet in the Sol System. It is home to several scientific bases, including one dedicated to studying prothean artifacts.
In the aftermath of the Reaper War, Martian colonies grew to support the large number of people stranded in Sol. These colonies have shrunk somewhat since the Serpent Nebula relay came back online in 2190. The largest industries on Mars are research and commerce.
The Martian moon Phobos has become the base of operations for the Turian Hierarchy's military presence in the Sol System.