Planet

I don't know, but it was fun to read

 

Thanks for this discussion. I love planets.

Speaking of Stratics (http://uo2.stratics.com/lore-and-history/historical-background-of-the-shattered-worlds/)

It reads that Earth does NOT exist within the 'closed world' of UO, and also because of this the pre-Avatar / Stranger COULD NOT travel there either.

Also, I wanted to add something about the moons:

"Under the auspices of Lord British, studies of the properties of the Moon gates are beginning to yield a clearer understanding of the Gates' mystical workings. People forecast that future citizens will use these gates as a normal means of distant travel. The destinations of the gates appear to be rigidly bound to the phases of the twin moons Trammel and Felucca. The appearance and disappearance of the gates are represented on most maps of the realm as phases of the moons. The gate active is indicated by the phase of the moon Trammel. Once a gate is entered, thy destination is indicated by the phase of the moon Felucca.
- from The History of Britannia, (Ultima IV)"

Their names existed at least as early as Ultima III for sure. They are featured on the back of the box of Ultima II, and here they are by name in runic on the Ultima III cloth map:

 

This is an interesting point for UO since the Stranger/Hero was in the world at the time of the shattering of the gem, he too would've been copied. So those copies would essentially be 'Outlanders' throughout UO. Not able to leave. Though I distinctly remember written story for UO where LB frequently wished for his return. So have to wonder where he went.