Jacques Vallée has said that the author(s) of the Ummo documents might be a real-world analogue of the fictional creators of Borges' "Tlön, Uqbar, Orbis Tertius". Historian Mike Dash writes that Ummoism began on February 6, 1966, in Madrid. On that day, Jordán Peña claimed to have had a close encounter of the first kind when he saw "an enormous circular object with three legs and, on its underside, a curious symbol: three vertical lines joined by a horizontal bar. The two exterior lines curved outward at the edges, which made the pictogram resemble the alchemical sign for the planet Uranus." (Dash, 299)