When dealing with the Emerald Tablets of Thoth for the most part it deals with Aliens from other galaxies through out the universe, but after the death of Thoth He ascended into the lower heavens which is the solar system of earth's sun.
This means that all the planets that go around our sun on earth are part of the lower heaven. And so the Emerald Tablets starts out with a being that Thoth called the Dweller, and this Dweller took over the island of Atlantis!