Beyond the Solar System: Exploring Galaxies, Black Holes, Alien Planets, and More; A History with 21 Activities
Prehistory 1600 Stargazers to Scientists eople have been exploring the universe for thousands of years Even cavemen gazing up at the stars were investigating what lay beyond in their own way Early humans believed they lived on a flat world Each day a godlike sun crossed the sky overhead The night sky was filled with trav eling lights and a changing moon Ancient people were wrong about Earth’s pancake shape and they didn't have a clue about black holes But this didn't keep them from putting what they did know about the universe to very good
This photograph of the Big Dipper was taken in March when it is upside down and its handle is to the right Can you see it NASA The Sun moon and stars appear to move disap pear and reappear in the sky in predictable patterns Figuring out tracking and predicting these heavenly patterns made the first clocks calendars and naviga tion tools possible The waning and waxing moon as it changes from full to new to full again marks the passage of 30 sunsets and sunrises a lunar month The stars Sun moon and the planets rise and set not because they are moving but because Earth is Our mobile planet gives us a constantly changing view of what surrounds us out in space Earth's tilted posture as it travels around the Sun each year creates seasons by altering day lengths and the arc of the Sun's daily path across the sky These changes announce the coming and going of
Since prehistory the changing seasons helped people know when it was time to plant or harvest move to winter hunting grounds or return to summer vil lages Stars too are seasonal calendars Maybe you've noticed this yourself The pattern of stars we call the Big Dipper changes position throughout the year Its handle points up in summer and down in winter Its Cuplike end holds water in autumn and empties it in spring BIG BEARS HUNTING GODS The Big Dipper is part of a constellation called Ursa Major or the Great Bear Constellations are groups of nearby stars that people have named after the shapes they make They are ancient star patterns and so have the names of ancient things mythical characters and creatures harps dragons unicorns parts of sailing ships and now forgotten tools DR The Great Bear constellation Ursa Major Library of Congress
