An artist's conception of the colonization of Mars, with a cutaway showing part of the interior

The colonization of Mars by humans is an ongoing debate. Some people want to colonize the planet Mars. Satellite imagery shows that there is frozen ground water on the planet. Mars also has a thin atmosphere. Because of this, it has potential to host humans and other organic life. That makes Mars the best choice for a thriving colony off the Earth. The Moon has also been proposed as the first location for human colonization but it is not known to have much air or water. It only has 0.16% air and has 14% water.