Mysterious organization claiming to present the knowledge of an alien civilization in letters to prominent scientists and researchers. Their symbol appeared in strange places and looks something like the alchemical symbol for Uranus.
According to Ummite DEI 98, son of DEI 97:
“It is our wish to inform the planet Earth of our origin and the intentions which have led us to visit you. We come from UMMO, a planet which orbits the star IUMMA, recorded in the astronomical maps of your planet as Wolf 424…the difficulties of comparing and checking the identifications of your system of astronomical references against our own is quite indescribable.”
Jacques Vallée has said that the Ummo documents might be a real-world analogue of the fictional creators of Borges’ “Tlön, Uqbar, Orbis Tertius”