Earth

Earth is the third planet of the Sol System, in Theta Sector. Although, before Star Ocean: The Last Hope, it is never visited outside cutscenes, it is an important location in the Star Ocean series, as it is the place of origin of the Pangalactic Federation (earlier known as the Terran Alliance), and thus, the starting point of mankind's expansion into the "Star Ocean".

Earth is also the origin of the Muah, a highly advanced people which is said to have existed on the Mu continent, located in the middle of the Pacific Ocean since the Pangaean era over 12,000 years ago. Legend says the continent sunk into the sea over the course of a single night. It is later revealed that a meteor struck, destroying their homeland and opening a vortex which transported the Muah themselves across the galaxy.

Thousands of years later, the Muah, or rather their genes, would play a vital role in humanity's attempts to create humans capable of surviving the harsh environment after the disastrous nuclear effects of World War III.

Whilst this plan resulted in 'limited success', which could be described as a failure, since it only produced three surviving subjects. However, where ever one's perspective may reside, it no doubt in the created events which would change the course of history in the universe.