<P> In Greek mythology, the Milky Way was formed after the trickster god Hermes suckled the infant Heracles at the breast of Hera, the queen of the gods, while she was asleep . When Hera awoke, she tore Heracles away from her breast and splattered her breast milk across the heavens . In another version of the story, Athena, the patron goddess of heroes, tricked Hera into suckling Heracles voluntarily, but he bit her nipple so hard that she flung him away, spraying milk everywhere . </P> <P> The Milky Way, or "milk circle", was just one of 11 "circles" the Greeks identified in the sky, others being the zodiac, the meridian, the horizon, the equator, the tropics of Cancer and Capricorn, Arctic and Antarctic circles, and two colure circles passing through both poles . </P> <P> In Meteorologica (DK 59 A80), Aristotle (384--322 BC) wrote that the Greek philosophers Anaxagoras (c. 500--428 BC) and Democritus (460--370 BC) proposed that the Milky Way might consist of distant stars . However, Aristotle himself believed the Milky Way to be caused by "the ignition of the fiery exhalation of some stars which were large, numerous and close together" and that the "ignition takes place in the upper part of the atmosphere, in the region of the world which is continuous with the heavenly motions ." The Neoplatonist philosopher Olympiodorus the Younger (c. 495--570 A.D.) criticized this view, arguing that if the Milky Way were sublunary, it should appear different at different times and places on Earth, and that it should have parallax, which it does not . In his view, the Milky Way is celestial . This idea would be influential later in the Islamic world . </P> <P> The Persian astronomer Abū Rayhān al - Bīrūnī (973--1048) proposed that the Milky Way is "a collection of countless fragments of the nature of nebulous stars". The Andalusian astronomer Avempace (d 1138) proposed the Milky Way to be made up of many stars but appears to be a continuous image due to the effect of refraction in Earth's atmosphere, citing his observation of a conjunction of Jupiter and Mars in 1106 or 1107 as evidence . Ibn Qayyim Al - Jawziyya (1292--1350) proposed that the Milky Way is "a myriad of tiny stars packed together in the sphere of the fixed stars" and that these stars are larger than planets . </P>

The milky way galaxy contains about 100 billion stars