Gargantia: Reclamation of Earth

Technology had developed astronomically fast after the invention of AI. With the help of AI, spacecraft had been drastically changed and evolved, soon travelling to other stellar bodies was quicker and manageable. The first and only planet to be colonized in the sol system was mars. However, the AI that accompanied the Mars colony was one of the first generation AIs, these AIs did not have morality, they only thought of success, which lead to the suggestion of genetic modifications to live on Mars and sadly after the AI had sabotaged the colonist they agreed to the modifications.

Without consolation of the United Earth Government about the genetic modifications, Earth sent a fleet of warships equipped with generation 2 AIs which were more human started a 10 year-long war. In the end, Earth was scarred with meteor strikes and Mars was turned into melted glass. However, there was debate whether the war was truly over, before the destruction of the Gen-M humans they had created a theoretical star bridge. With Earth now entering an ice age and habitual land now minimal the United Earth Government decided to follow the Gen-M humans and hunt them down while also finding a new planet to colonise.

And so Earth was left alone for thousands of years until Ships of unknown origin entered Earths atmosphere and changed the world forever.