Universe Author: Giles Sparrow Consultant: Jerry Stone 001_Half_title.indd 1 30/07/18 4:02 PM Contents Senior editor Carrie Love Project art editor Lucy Sims Project editor Ishani Nandi 4 Our place in space Editor Anwesha Dutta Assistant editor Shambhavi Thatte US editor Allison Singer 6 The Big Bang Art editors Kartik Gera, Shipra Jain Managing editors Laura Gilbert, Alka Thakur Hazarika Managing art editors Diane Peyton Jones, 8 Space objects Romi Chakraborty Jacket designer Suzena Sengupta Jacket coordinator Francesca Young 10 Life of a star DTP designers Rajesh Singh Adhikari, Pawan Kumar Picture researcher Sakshi Saluja CTS manager Balwant Singh 12 Star birth Pre-producer Rob Dunn Senior producer Isabell Schart Creative director Helen Senior 14 Types of stars Publishing director Sarah Larter Educational consultant Jacqueline Harris 16 Multiple stars DIGITAL OPERATIONS, DELHI Editor Suruchi Bhatia Production co-ordinator Manish Bhatt 18 Black holes DK CREATIVE, DELHI Assistant editor Prerna Grewal 20 Galaxies Art editors Radhika Banerjee, Mohd Zishan Managing editor Monica Saigal Deputy managing art editor Ivy Sengupta 22 Milky Way eISBN: 9781465483348 Digital edition published by Dorling Kindersley Limited 24 The Sun First American edition, 2018 Published in the United States by DK Publishing 345 Hudson Street, New York, New York 10014 26 Solar System Copyright © 2018 Dorling Kindersley Limited DK, a Division of Penguin Random House LLC All rights reserved. Without limiting the rights under the copyright reserved above, no part of this publication may be reproduced, stored in or introduced into a retrieval system, or transmitted, in any form, or by any means (electronic, mechanical, photocopying, recording, or otherwise), without the prior written permission of the copyright owner. Published in Great Britain by Dorling Kindersley Limited DK books are available at special discounts when purchased in bulk for sales promotions, premiums, fund-raising, or educational use. For details, contact: DK Publishing Special Markets, 345 Hudson Street, New York, New York 10014 [email protected] A WORLD OF IDEAS: SEE ALL THERE IS TO KNOW www.dk.com International Space Station (ISS) Replica of Galileo's telescope 2 US_002-003_Contents.indd 2 14/08/18 10:55 AM 28 Beyond Neptune 52 Exoplanets 30 Rocky planets 54 Is there life out there? 32 Gas giants 56 James Webb Telescope 34 Earth’s Moon 58 Universe facts and figures 36 Moons 60 Stargazing 38 Rocks in space 62 Careers in space 40 The view from Earth 64 Glossary 42 Constellations 66 Index 44 Astronomy 68 Acknowledgments 46 Meet the expert 69 Quiz 48 Space photos 70 Quiz answers 50 Exploring space e th e planet Mars M o o n rock Insid S p a c e S h u t t le D is c o v e r y Hockey Stick Galaxy 3 US_002-003_Contents.indd 3 14/08/18 10:55 AM Our place in space Our universe is enormous—in fact it’s everything there is. Long ago, people used to think that Earth was the center of everything, but now we understand that our planet is just one tiny speck in space. THE SOLAR SYSTEM Our solar system is Where do we fit in? mostly empty space. The scale of the universe is Even our moon is 30 Earth diameters away. so huge that we can’t really OUR PLANET Earth is 93 million miles imagine it all at once. The best (150 million km) from way of thinking about it is to The Earth is 7,918 the sun, but distant see how things from our miles (12,742 km) comets can orbit up everyday lives fit into it. across. It would to a light-year away. take an average person about 20 million steps to CITIES walk around Medium-sized the equator. cities are usually about 6–12 miles (10–20 km) across. PEOPLE It might take a Most people few hours to cross are between them by foot. 3–61⁄2 ft (1–2 m) tall. Walking at average speed, we cover about 3 miles (5 km) in an hour. 4 US_004-005_Our_place_in_space.indd 4 30/07/18 12:10 PM THE MILKY WAY Our home galaxy is about 100,000 light- years across and contains between 100 and 400 billion stars. Our solar system is about 26,000 light- years from the center. THE LOCAL GALACTIC GROUP UNIVERSE OF GALAXIES The Milky Way is one of the bigger members of a galaxy group roughly The universe contains 10 million light-years across. at least 200 billion galaxies and stretches across at least 156 billion light-years. We What is Light-years can see objects up to 92 1 2 3 4 billion light-years away. a light-year? Astronomers measure huge cosmic distances in terms of light-years, the distance that light (the fastest thing in the universe), travels in one year. One light-year Alpha Centauri The closest star is about 5.9 trillion miles system to Earth or 9.5 trillion km. 5 US_004-005_Our_place_in_space.indd 5 30/07/18 12:10 PM 1 2 3 US_006-007_The_Big_Bang.indd 6 06/08/18 4:18 PM The universe is still expanding from the Big Bang—in fact it’s growing faster than ever. 4 5 KEY » 1: Big Bang The universe began with a huge explosion. » 2: Growing bigger Space grew quickly and was hot. It then started to cool down, and matter formed. » 3: Making matter Tiny particles called protons started to form. These make up the center of atoms, the building blocks of everything. » 4: Stars and galaxies The first giant stars formed after about 200 million years. Their gravity pulled in matter to form growing galaxies. » 5: The universe today Heavier elements made by earlier stars helped form planets in today’s universe. The Big Bang The universe was born in an explosion called the Big Bang, 13.8 billion years ago. The Big Bang created all the matter in the universe. Matter is the stuff that everything is made of. It took a long time for that matter to clump together into larger objects, such as planets, moons, and stars. 7 US_006-007_The_Big_Bang.indd 7 06/08/18 4:18 PM Stars Stars are huge balls of gas that release heat and light. They are often found in pairs or clusters. Space objects Planets There are different types of The Universe contains objects, planet that orbit the stars; rocky planets like the Earth, from asteroids, planets like Earth, gas planets like Jupiter, and to stars, many far bigger than our dwarf planets like Pluto. The Sun, and enormous galaxies! Then planet shown here is Venus. there are the objects that humans have sent into space, including satellites and spacecraft. Galaxies Galaxies are the largest objects in the Universe. They are made up of many millions of stars, along with gas and dust. 8 008-009_Space_objects.indd 8 09/08/18 12:47 PM