The Dogon are an ethnic group living in the central plateau region of Mali, south of the Niger bend near the city of Bandiagara in the Mopti region. The population numbers between 400,000 and 800,000 The Dogon are best known for their mythology, their mask dances, wooden sculpture and their architecture. The past century has seen significant changes in the social organization, material culture and beliefs of the Dogon, partly because Dogon country is one of Mali‘s major tourist attractions. Certain researchers investigating the Dogon have reported that they seem to possess advanced astronomical knowledge, the nature and source of which has subsequently become embroiled in controversy. From 1931 to 1956 the French anthropologist Marcel Griaule studied the Dogon. This included field missions ranging from several days to two months in 1931, 1935, 1937 and 1938 and then annually from 1946 until 1956. In late 1946 Griaule spent a consecutive thirty-three days in conversations with the Dogon wiseman Ogotemmêli, the source of much of Griaule and Dieterlen’s future publications. They reported that the Dogon believe that the brightest star in the sky, Sirius (sigi tolo or ‘star of the Sigui’), has two companion stars, pō tolo (the Digitaria star), and ęmmę ya tolo, (the female Sorghum star), respectively the first and second companions of Sirius A. Sirius, in the Dogon system, formed one of the foci for the orbit of a tiny star, the companionate Digitaria star. When Digitaria is closest to Sirius, that star brightens: when it is farthest from Sirius, it gives off a twinkling effect that suggests to the observer several stars. The orbit cycle takes 60 years. They also claimed that the Dogon appeared to know of the rings of Saturn, and the moons of Jupiter.