Aesesush is a planet in the Prime Reality.
Nothing has been revealed of the climate or environment of Aesesush, but it is inhabitable by humanoids, as its primary species' default form appears to be just that. The shapeshifters who live in this world can presumably transform into any animal they please, and they are extremely long-lived.
Unknown, but it and Earth had to have made first contact at or before 3,000 B.C., since one of the original Olympian Rangers was Aesesushite. They have their own Power Rangers, who as a rule do not have secret identities.