ASTRONOMY||100% Verified Correct Study Material

ASTRONOMY 10.1 Properties of the Moon 276 10.2 Total Solar Eclipses 286 10.3 Total Lunar Eclipses 287 11.1 Some Periodic Comets 301 11.2 Principal Annual Meteor Showers 306 11.3 Large Meteorites on Display in the U.S. 307 11.4 The Occurrence of Meteorite Types 308 xv INTRODUCTION: COSMIC VIEW Strange is our situation here upon Earth. Each of us comes for a short visit, not knowing why, Yet sometimes seeming to divine a purpose. Albert Einstein (1879–1955) On a clear night in a place where the sky is really dark, you can see about 2000 stars with your unaided eye. You can look trillions of kilometers into space and peer thousands of years back into the distant past. As you gaze at the stars you may wonder: What is the pattern or meaning of the starry heavens? What is my place in the vast cosmos? You are not alone in asking these questions. The beauty and mystery of space have always fasci-nated people. Astronomy is the oldest science—and the newest. Exciting discoveries are being made today with the most sophisticated tools and techniques ever avail-able. Yet dedicated amateurs can still make important contributions. This book will teach you the basic concepts of astronomy and space exploration. You will more fully enjoy observing the stars as your knowledge and understanding grow. You will be better able to surf the Web and to read more on topics that intrigue you, from ancient astronomy to the latest astro-physical theories and spaceflights. As you teach yourself astronomy, refer to: The Star maps and Moon map at the back of this book. These special, easy-to-read maps will help you locate and identify particularly inter-esting objects in the sky. Simple activities you can do that demonstrate a basic idea. 1 2 ★ ASTRONOMY Internet link to spectacular images and new reports. Now, begin reading about the enormous tracts of space and time we call the universe, and stretch your mind! Our home is planet Earth, a rocky ball about 13,000 km (8000 miles) in diameter suspended in the vastness of space-time (Figure I.1). Figure I.1. Earth photographed from space. Sunshine dramatically spotlights Earth’s blue ocean, reddish-brown land masses, and white clouds from the Mediterranean Sea area to the Antarctica polar ice cap.