Mars is another planet within Earth's solar system which is the home planet for the Martians. Mars was destroyed because of the war; just like the war on Krypton.
Reign of the Superman History
Pre-Crisis/Pre-Zero Hour History
By the 31st Century, there was a great city on Mars, known as Mars City. The city was protected by an impenetrable dome. There was a miniature version of it on display in Metropolis on Earth. ("Supergirl's Greatest Challenge!")
New 52 History
A colony had been set up on Mars by 2012, and Metaleks attacked it, converting it to spare metal in their attempt to convert it into a new home for the dead race that had built them. Superman saved the colonists and forged peace between them and the Metaleks, but the colony was soon attacked by the Multitude. Superman fought them off. ("Mission to Mars")
Last Days of Krypton History
- Main Article: Martians
The planet was previously inhabited by two races of martians, the White Martians and the Green Martians, both of whom are now extinct except for a few survivors like Martian Manhunter.
New 52 Continuity
There is a human colony on the planet as of 2012. ("Mission to Mars")