Earth

Earth is a planet of key importance across the entire Xeno-series. It is the native planet of humanity.

In Xenogears
The history of Earth is virtually identical to how it is in real life until the year 2001 A.D., where the Zohar was discovered. Because of its mysterious properties, some people took to the theory that the Zohar created life on Earth.

Many years later, in 2510 A.D., a project to emigrate out of Earth was set into motion. In 0016 T.C., (2526 A.D.) humanity began to fully emigrate out of the planet, never to return. For unknown reasons, the planet became a forbidden region of space, with its new name of ‘’Lost Jerusalem.’’

Millennia later, when the Eldridge was hijacked by Deus, it began to change course to Lost Jerusalem, referred to by the crew as “the main planet”. The ship did not reach its new destination, with it crash landing on a remote planet in space.

In Xenoblade Chronicles 3
It is revealed by the Queen of Agnus, Nia that Earth was split into the worlds of Bionis and Mechonis and Alrest when Klaus activated the Conduit. Both worlds will inevitably reunite, but doing so will destroy both worlds, known as the Intersection, leaving only light. As the worlds got closer, the Nia manages to make contact with her Kevesi counterpart, Melia for the first time. To prepare for the Intersection, they built an arc from each side, known as Origin to preserve the consciousness of both worlds and reboot them. However the reboot process failed and both worlds fused into Aionios due to Z and Moebius who captured Melia to access Origin's memory banks and take it over.

After Z's death, Origin starts up and the world splits back into the two original worlds.

In Xenoblade Chronicles 3: Future Redeemed
A simulation of Earth is visited by Matthew and the party; a contemporary suburban neighborhood with an urban city and First Low Orbit Station in the distance. This is where Matthew finally encounters Na'el, who describes this as a perfect world.

A radio also plays in the distance, giving more insight on the culture of the planet. An ongoing project known as the Earthlife Colonization Project took place, with at least eight colony ships departing Earth in Project Exodus, with at least five more planned out. A proposal human rights protection bill concerning the Saviorites was also speculated to have been scrapped, with a statement from Dimitri Yuriev involving the rumors.

The epilogue of the game concerns the ending of the base game; as the two worlds are seen splitting apart, they suddenly flash into light as a third world comes into sight, with a blue streak of light descending from space into the newly-created planet.