Earlier today, Blizzard announced a new map coming to Overwatch, called the "Horizon Lunar Colony." The colony is home to where Winston grew up, and it is where genetic testing was performed on the gorillas. The setting of the moon is the first time in Overwatch history that players can compete in a location that is not on Earth.
Horizon Lunar Colony is an assault map, meaning that there are two objective points to either attack or defend. The map has a lot of low and high ground, giving all of the heroes paths that play to their strengths. In a developer update, Jeff Kaplan (one of the leads on Overwatch) said that since the map is on the moon, there are small sections of the map that have less gravity. Along with this little change, there will also be an arcade mode that not only features low gravity throughout the entire colony but throughout every other preexisting map as well.
Currently, Horizon Lunar Colony is only available in the PTR (Public Test Realm) servers on PC, but it should be fully released soon.