The Nature of Planets, Dwarf Planets, and Space Objects
CONTENTS INTRODUCTION CHAPTER 1 WHAT Is a PLANET 1ol CHAPTER 2 MoTIONS OF THE PLANETS 29 CHAPTER 3 DWARE PLANETS 39 CHAPTER 4 ASTEROIDs 58 CHAPTER 5 COMETS 66 CHAPTER 6 METEORS AND METEORITES CONCLUSION 88 89 91 GoSSARY For MORE INFORMATION BIBLIOGRAPHY INDEX 94 95
Nhe skies hold many marvels Among the most fascinating are planets dwarf planets and space objects such as asteroids comets and meteors Astronomers view these celestial bodies through powerful telescopes and send out space probes and satellites to record data and take photographs These pages will take you on your own exciting journey among planets and space objects Planets have long been known to be large natural bodies that orbit around the Sun but the specifics of the definition have changed over the years The most recent definition includes eight planets in the solar system Mercury Venus Earth and Mars known as inner planets and Jupiter Saturn Uranus and Neptune outer planets From 1930 until 2006 Pluto was considered a planet too But after scientists discovered several other dis tant bodies similar to Pluto orbiting the Sun Pluto was reclassified as a dwarf planet Most astronomers believe that the solar system started developing around 4 6 billion years ago from a large cloud of gas and dust called the solar nebula Gravity caused the matter to contract and the cloud began to spin flattening into a disk The Sun formed
The Nature of Planets, Dwarf Planets, and Space Objects
Peering through a telescope, you are likely to encounter a host of celestial bodies—anything from planets to comets—speckling the night sky.
About This Book
By: Michael Anderson
Illustrated by:
Published by: Rosen Publishing provided by Britannica
