Earth is a planet in the Solar System. It is the home of humans, and is where TMA-0 was discovered. Earth is the third planet from the Sun, and is located in the solar system's habitable zone.
Four million years ago, members of Australopithecus Afarensis encountered TMA-0, a monolith that appeared overnight. It influenced their cognitive abilities and higher brain functions, leading to the ability to hunt and use tools. This eventually led to the evolution of modern humans.