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Using the Plough to find the Pole StarUsing the Plough to find the Pole Star Constellations are areas of the sky, divided up for the purpose of locating and identifying stars, galaxies and other objects in the heavens, as well as the star patterns they contain. Years ago, seafarers used the constellation Ursa Major (the Great Bear) to help with navigation. The seven middle stars of Ursa Major make up the familiar Plough. A line running from the two end stars in the Plough, Merak and Dubhe, point to Polaris, the Pole Star, which lies almost exactly due north.

A 17th-century map of the constellationsA 17th-century map of the constellations

Mapping the night sky

Northern Hemisphere constellationsNorthern Hemisphere constellationsYears ago, before telescopes were invented, early astronomers grouped the stars together into patterns, imagining their shapes to look like gods, heroes and sacred beasts from popular legends. The ancient Greeks knew of 48 constellations, having inherited some from the Babylonians. When Europeans sailed the southern oceans on voyages of exploration, they discovered constellations they had never seen before. Today, the sky is divided into 88 constellations.

Southern Hemisphere constellationsSouthern Hemisphere constellations

Southern Hemisphere

Approximately 10,000 stars are visible with the naked eye.

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