Professor Cox - The Planets

ANDREW COHEN

WITH

PROFESSOR BRIAN COX

© JEFF DAI / SCIENCE PHOTO LIBRARY

William Collins

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This eBook edition published by William Collins in 2019

Text © Brian Cox & Andrew Cohen 2019

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Brian Cox and Andrew Cohen assert their moral right to be identified as the authors of this work in accordance with the copyright, Designs and Patents Act 1988

Jupiter cover image: NASA/JPL/Space Science Institute

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Source ISBN: 9780007488841

Ebook Edition © April 2019 ISBN: 9780008313470

Version: 2019-05-17

TO ANNA – AMONGST THE VASTNESS OF THIS STORY HOW LUCKY AM I TO HAVE FOUND YOU.

ANDREW COHEN

COVER

TITLE PAGE ANDREW COHEN WITH PROFESSOR BRIAN COX

COPYRIGHT

DEDICATION TO ANNA – AMONGST THE VASTNESS OF THIS STORY HOW LUCKY AM I TO HAVE FOUND YOU. ANDREW COHEN

SOLAR SYSTEM AN INTRODUCTION

AN INTRODUCTION AN INTRODUCTION

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MERCURY + VENUS

A MOMENT IN THE SUN

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EARTH + MARS

THE TWO SISTERS

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JUPITER

THE GODFATHER

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SATURN

THE CELESTIAL JEWEL

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URANUS NEPTUNE PLUTO

INTO THE DARKNESS

INDEX

ACKNOWLEDGEMENTS

ABOUT THE AUTHOR

ABOUT THE BOOK

ABOUT THE PUBLISHER

AN INTRODUCTION

PROFESSOR BRIAN COX

© Shutterstock

WANDERING LIGHTS

In the daytime, our universe stretches only as far as the horizon. The Sun hides in plain sight because it is too bright for us to see it directly. Only rarely do we glimpse a watercolour moon. Unless we think hard, our intellects are confined to the surface of the Earth. After sunset, beyond cities, the Universe appears; a destination for the imagination, albeit separated by a seemingly unbridgeable gulf. This may be true for the stars, but it is not so for the planets. There are times when Mars, Venus, Jupiter and Saturn dominate the sky; bright lights that shift position nightly against the fixed stars, commanding our attention even if we aren’t certain what we’re looking at. The distances are still vast by terrestrial standards, but despite appearances the gulf is certainly not unbridgeable, because we have visited all of these planets and taken our first steps into the outer reaches of the Solar System beyond. And yet the wandering lights in the dark still feel detached from human affairs, and the time and effort we’ve spent in visiting them might seem to be an indulgence. This assumption, however, is profoundly wrong.

The exploration of the planets is not an indulgence. If we want to know how we came to be here we need to understand the histories of the planet that gave birth to us and the system that gave birth to it. We are children of Earth and also children of the Solar System.

© BABAK TAFRESHI / SCIENCE PHOTO LIBRARY

The Milky Way in the night sky over Sliding Spring Observatory, New South Wales, Australia.

The Solar System is a system. The Sun and the eight major planets and countless billions of minor planets, moons, asteroids, comets and unclassified lumps of ice and rock were formed back in the mists of time and they continue to evolve as one. We rarely notice the dynamic, interconnected nature of our system, although asteroid strikes on our planet are not such a rare occurrence. The Chelyabinsk impact in February 2013 injured 1,500 people when a 12,000-tonne asteroid broke up as it entered the Earth’s atmosphere at 60 times the speed of sound, and the Tunguska airburst in Siberia in 1908 flattened 800 square miles of forest in an explosion comparable to that of the most powerful hydrogen bomb ever tested. The surface of the Moon bears testament to a record of violence and destruction from the skies that the Earth has also endured, but the relentless erasure of craters by weathering and our good fortune that no major impacts have occurred in recorded human history are the reason for our misplaced sense of isolation from the heavens.

© Science History Images / Alamy Stock Photo