W A X M A N L E R N E R THIS PAGE INTENTIONALLY LEFT BLANK by LauRa HamiLton Waxman dLERnER PubLications comPany • minnEaPoLis The images in this book are used with the permission of: NASA/JPL-Caltech, p. 4; The International Astronomical Union/Martin Kornmesser, p. 5; NASA/JPL/GSFC, pp. 6, 21; © Steve A. Munsinger/Photo Researchers, Inc., p. 7; © Photononstop/SuperStock, pp. 8, 47; © Jerry Lodriguss/Photo Researchers, Inc., p. 9; © Laura Westlund/Independent Picture Service, pp. 10-11, 12, 13 (both), 15, 26; NASA/JPL, pp. 14, 25, 33, 40, 42; © Atlas Photo Bank/Photo Researchers, Inc., p. 16; NASA/John Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington, p. 17; © SuperStock/SuperStock, p. 18; © NASA/David Anderson/ Photo Researchers, Inc., p. 19; NASA/JSC, pp. 20, 39; © StockTrek/Photodisc/Getty Images, p. 22; NASA/GSFC, p. 23; ESA/DLR/FU Berlin (G. Neukum), p. 24 (left); NASA/JPL-Caltech/ University of Arizona, p. 24 (right); NASA/JPL/Space Science Institute, pp. 27, 28, 31, 41; NASA/JPL/DLR, p. 29; NASA and E. Karkoschka (University of Arizona), p. 30; NASA/JPL/STScI, p. 32; © Friedrich Saurer/Photo Researchers, Inc., p. 34; © Detlev van Ravenswaay/Photo Researchers, Inc., p. 35; © age fotostock/SuperStock, p. 36; © Jean-Leon Huens/National Geographic/Getty Images, p. 37; © Image Asset Management Ltd./SuperStock, p. 38; Walt Feimer, Goddard Space Flight Center/NASA, p. 43; © Lester Lefkowitz/Taxi/Getty Images, p. 46; NASA/John Hopkins University Applied Physics Laboratory/Southwest Research Institute/ Goddard Space Flight Center, p. 48 (top); NASA/GRIN, p. 48 (bottom). Front cover: © Detlev van Ravenswaay/Photo Researchers, Inc. (main); NASA, ESA, and The Hubble Heritage Team (STScI/AURA), Y. Momany (University of Padua) (background). Back cover: NASA, ESA, and The Hubble Heritage Team (STScI/AURA). Copyright © 2010 by Lerner Publishing Group, Inc. All rights reserved. International copyright secured. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means—electronic, mechanical, photocopying, recording, or otherwise—without the prior written permission of Lerner Publishing Group, Inc., except for the inclusion of brief quotations in an acknowledged review. Lerner Publications Company A division of Lerner Publishing Group, Inc. 241 First Avenue North Minneapolis, MN 55401 U.S.A. Website address: www.lernerbooks.com Library of Congress Cataloging-in-Publication Data Waxman, Laura Hamilton. The solar system / by Laura Hamilton Waxman. p. cm. — (Early bird astronomy) Includes index. ISBN 978–0–7613–3874–1 (lib. bdg. : alk. paper) 1. Solar system—Juvenile literature. I. Title. QB501.3.W39 2010 523.2—dc22 2009022100 cMaanputfaioctunr etdo in cthoem Uneit.e d cStaatpest oifo Anm etroic acome. caption to come. caption to come. 1 – BP – 12/15/09 eISBN 978-0-7613-5933-3 ccoonntteennttss Be a Word Detective . . . . . . . . . . . . . . . . . . . . 5 Chapter 1 EaRtH’s nEigHboRHood . . . . . . . . . . . . . . 6 caption to come. caption to come. caption to Chapter 2 come. caption to come. at tHE cEntER . . . . . . . . . . . . . . . . . . . . . 10 Chapter 3 RocKy PLanEts . . . . . . . . . . . . . . . . . . . . 14 Chapter 4 gas giants . . . . . . . . . . . . . . . . . . . . . . . .25 Chapter 5 smaLLER nEigHboRs . . . . . . . . . . . . . . . . .34 Chapter 6 studying tHE soLaR systEm . . . . . . . . . . .37 A Note to Adults on Sharing a Book. . . . . . . . . . . . 44 Learn More aboutthe Solar System . . . . . . . . . . . .45 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48 caption to come. caption to come. caption to come. caption to come. 44 BBee aa WWoorrdd ddeetteeccttiivvee Can you find these words as you read about the solar system? Be a detective and try to figure out what they mean. You can turn to the glossary on page 46 for help. asteroid crater spacecraft astronaut dwarf planet telescope astronomer gravity universe atmosphere orbit volcanoes comet solar system 55 do you recognize this picture? it is a picture of planet Earth. Where does Earth lie in space? chapter 1 earth’s neighBorhood Earth is our home planet. It is where billions of people, animals, and plants live. But did you know that Earth has a home too? It is called the universe. The universe includes the planets and all of outer space. 6666 [7] Earth lies in one part of the universe. This part is called the solar system. It includes the Sun and eight planets. Dwarf planets are also part of the solar system. Dwarf planets are smaller than other planets. Asteroids (A-stur-oydz) and comets are even smaller. These rocky and icy objects belong to the solar system too. in this illustration, you can see most of the planets that are part of the solar system. the glowing yellow ball at top right is the sun. the sun is actually the largest object in the solar system. 7 You can see some of Earth’s neighbors in the sky. The Moon is Earth’s closest neighbor. It often looks big and bright at night. the moon rises over the ocean. the moon is the closest object to Earth. it looks much bigger than stars and planets because it is so close to Earth. 8