Anaxagoras of Clazomenae (a major Greek city of Ionian Asia Minor), a Greek philosopher of the 5th century B.C.E. (born ca. 500-480), was the first of the Presocratic philosophers to live in Athens. He propounded a physical theory of “everything-in-everything,” and claimed that nous (mind or intellect) was the motive cause of the cosmos. He was the first to give the correct explanation of eclipses, and was both famous and notorious for his scientific theories, including the claims that the sun is a mass of red-hot metal, that the moon is earthy, and that the stars are fiery stones.
See the full article at http://plato.stanford.edu/entries/anaxagoras/