Many primitive peoples tell how heavenly gods visited and taught their ancestors. This is how the Dogon from the republic of Mali know astronomic details of the Sirius system. Their holy sign of iron shows the orbits of the stars Sirius B and C. Strange – the white dwarf Sirius B can only be seen with a telescope. And modern astronomy determined details only in the last century. According to our current knowledge, Sirius B takes 50 years to complete one revolution around Sirius A. Surprisingly, the Dogon have celebrated the Sirius system regularly every 50 years for generations. This is where their gods, the Nommos, are said to live. With the four metre high Sirigi masks, they imitate the landing of the gods’ ark on Earth.