How to make yourmobilesYou will need some thread to hang your mobiles.

1 You will find the mobiles inside this book attachedto pages 6 and 7, and pages 10 and 11. Carefully detachthe mobile pages along the perforated edges.

2 Press out all the mobile illustrations, except thepieces marked A, B, C and D. Cut small lengths ofthread. Tie the thread to the mobile pieces by pushingthe ends into the slits and winding them round at leastthree times.

3 Press out one part of the hanger, marked A.Following the positions shown in the diagrams,assemble the mobile pieces and tie them to A.

You can make the threads that link the mobile pieces aslong as you like.

Planets Deep space

Planets Deep space

4 Now do the same with the second part of the hanger,marked B. Tie a thread to the top of B.

5 Assemble the hanger by fitting A and B together.Following this diagram, slide A into B through thediagonal slit in B.

6 Press out the ring marked C. Pass the thread fromthe top of B through the centre of it. Press C onto thetop of the hanger until the four points of the X-shapedhole fit into notches cut in the hanger.

7 Press out the hook marked D and attach it to thethread from the top of the hanger. You can use thehook to hang up your mobile.

Sun

Jupiter

Mars

Earth

Mercury

Venus

Pluto

Neptune

Uranus

Saturn

AM A Z I N G

The SunLike all stars, the Sun is a slowly spinningball of hot gas. Life on Earth could not existwithout it. The Sun is so huge, nearly1,400,000 Earths could fit inside it!

CometsComets, balls of dust and ice, orbit the Sunalong stretched-out oval paths. Halley’sComet passes by Earth every 76 years. Itstail always points away from the Sun.

Pioneer 10 space probe

Jupiter

Pluto

Mercury

Mars

Earth Galileo space probe

Empire of the Sun

THIS IS A DIAGRAM of our Solar System.At thecentre lies the Sun, our local star. Circling round it are

nine planets, including our own planet, Earth. Their paths,or orbits, are shown in different colours. The Solar Systemalso includes moons, asteroids, comets and large amountsof gas and dust.

The planetsThe planetsall orbit the Sun in the samedirection, and in almost circular paths. Plutohas an orbit more oval in shape. Part of itsjourney takes it inside Neptune’s orbit.

Space probesWe have found out a great deal about theSolar System from space probes.Theseunmanned spacecraft have flown close byplanets and sent us back pictures of them.

Sun

Saturn

Uranus

Neptune

Venus

A s t e r o i d s

Voyager 2 space probe

Voyager 1 space probe

A barren worldThe Moon is much smaller thanour planet and, unlike ours, abarren world. There is no air orwater, so no plants or animalscan live there. Its surface is pittedwith craters. These have beenblasted out by pieces of rock,called meteorites, crashing downfrom space. On a clear night,using a pair of binoculars, youcan see the ‘splash’ markssurrounding several craters.The Moon also has mountains

and dark plains which earlyastronomers once thought wereseas. They are still called by theLatin name for sea, mare.

Next total lunar eclipses:16 Sept 1997 Visible from Australia, Africa, Europe21 Jan 2000 Visible from Asia, North America, Europe

Next total solar eclipses:26 Feb 1998 Visible from Hawaii, America, West Africa11 Aug 1999 Visible from Greenland, Europe, Middle East

Light fromthe SunEarth

MOON Diameter3476 km • Averagedistance from Earth384,600 km •Surface temperature-155˚C to -105˚C

Disappearing tricksSometimes, the Moon blots out our view of theSun completely, an event called a solar eclipse(seen in this sequence 1-3, right).Onother occasions, when Earth lies directlybetween the Sun and the Moon, Earth casts itsshadow on the Moon. This is called a lunareclipse(left).The Moon turns a rosy colour.

The Moon

THEMOON is neither a star nor aplanet. It is a ball of rock that travels

round our planet Earth. It takes about 27days to complete a circle. The Moon isthe brightest object we can see in thenight sky, although the light it ‘shines’ isreflected from the Sun.

The Moon seems to change shapefrom one night to the next. This happensbecause as it travels round Earth, it spinsonly once, so the same face remainspointed towards us at all times. It is ourview of the sunlit part that changes. Whenthe face pointed towards us is turnedaway from the Sun, we cannot see theMoon at all: a New Moon (1).When it isturned towards the Sun, we can see acomplete disc which we call a Full Moon(5).In between, it passes throughcrescent (2),quarter (3)and gibbous (4)

Moon

Our view of the Moon’schanging phases

Fry or freezeMercury is the nearest planet to the Sun.You might think it would be the hottestplanet, and where it faces the Suntemperatures do soar above 400˚C. But atnight, temperatures plunge to -180˚C.

Planet from hellVenus is the hottest planet in the SolarSystem and probably the nastiest. Its denseatmosphere keeps the heat in. If anyone wereunlucky enough to land on Venus, he or shewould be burnt to a cinder, crushed by the airpressure and suffocated by carbon dioxide—all at the same time!

Alive or dead?Mars, the red planet, is the only other planetin the Solar System where life could possiblybe. Dry riverbeds on its surface show thatwater once flowed on Mars. Daytimetemperature at the Martian equator maysometimes reach a warm 20˚C (althoughaverage temperatures are a lot colder than onEarth). But if life ever existed on this planet, itprobably doesn’t now. Mars is a barrenlandscape of plains, canyons and immenseextinct volcanoes. One, Olympus Mons, is thehighest mountain in the Solar System. It isnearly three times as high as Mount Everest.

Magnificent ringsSaturn,the second largest planet, is famousfor its rings. Jupiter, Neptune and Uranus allhave faint rings, but Saturn’s are broad andmagnificent. There are thousands of rings.Each is made up of billions of blocks of iceand rock, the largest about the size of a house.Like the other giant planets, Saturn is mademostly of gas.

Side spinUranus is a pure, pale blue-green ball.Unlike all the other planets, it spins on itsside, so that each of its poles, in turn, faces theSun. This means that, over the 84 yearsUranus takes to travel around the Sun, eachpole has 42 years of sunlight followed by 42years of darkness. Uranus has 11 very faintrings, each only a few kilometres wide.

Fierce windsNeptune is quite similar to Uranus in size.Sometimes, its blue globe is streaked bywhite, wispy clouds. Winds whip round at upto 2000 km/h.

Cold and lonelyPlutois the outermost planet. It is also thecoldest and smallest. Pluto does have a closecompanion, however: its moon, Charon.

Our local starThe Sun,our local star, is much bigger inrelation to the planets than these illustrationsshow. Its diameter is nearly ten times that ofJupiter. The Sun is a hot, spinning ball of gaswith temperatures at its centre of 14 million˚C. Its surface bubbles and spits like water ina boiling kettle. Now and again, great flaresand loops burst from it into space.

Swirling cloudsJupiteris the largest of all the planets. Infact, it is big enough to contain all the otherplanets put together. With its colourfulpatterns of red, gold and white, Jupiter lookslike a giant marble. But its ‘surface’ is notsolid at all: those swirling patterns are cloudsin its atmosphere. The Great Red Spot is agiant storm that has been raging for at least300 years. Only Jupiter’s core (probably twicethe size of Earth itself) is solid rock.

Our home in spaceEarth,our home planet, has exactly the righttemperature to support life. There is alsoliquid water and an atmosphere—a blanket ofgas that surrounds the globe—to keep out theSun’s harmful rays but keep insome of thewarmth. Earth has several layers inside: a thin,hard crust, a thick semi-solid mantle and a hotball of solid iron at its core.

Planets mobileMERCURY Diameter 4880 km • Day58.6 days • Year 88 days • Averagedistance from Sun 58 million km •Nearest to the Sun • No moons

JUPITER Diameter 142,960 km • Day 9.8 hours • Year 11.8years • Average distance from the Sun 779 million km •5th from the Sun • 16 moons

NEPTUNE Diameter 49,557 km • Day 16.1 hours • Year164.8 years • Average distance from Sun 4496 million km •8th from the Sun • 8 moons

URANUS Diameter 51,166 km • Day 17.2 hours • Year 84years • Average distance from Sun 2869 million km • 7thfrom the Sun • 15 moons

SATURN Diameter 120,514 km • Day 10.2 hours • Year 29.5years • Average distance from Sun 1427 million km • 6thfrom the Sun • 18 moons

PLUTO Diameter 2300 km • Day 6.4days • Year 248 years • Averagedistance from Sun 5900 million km •9th from the Sun • 1 moon

SUN Diameter1,400,000 km •Rotation period atequator 25 days •Surface temperature5500˚C

MARS Diameter 6797 km • Day 24.6hours • Year 687 days • Averagedistance from Sun 228 million km •4th from the Sun • 2 moons

EARTH Diameter 12,761 km • Day 24hours • Year 365.26 days • Averagedistance from Sun 149.7 million km •3rd from the Sun • 1 moon

VENUS Diameter 12,109 km • Day 243days • Year 225 days • Averagedistance from Sun 108 million km •2nd from the Sun • No moons

Worlds of ice and rock

ALL THE PLANETS of the Solar System,except for Mercury and Venus, have

moons. Even tiny Pluto has a moon, Charon.Saturn has 18 of them, Jupiter 16, including four‘giants’: Ganymede, Callisto, IoandEuropa.The largest of Jupiter’s moons,Ganymede, is larger than both Mercury andPluto.

Some of the moons would be fascinatingplaces to visit. Triton,a moon of Neptune, isthe coldest place in all the Solar System. It haspink ice. Io looks like a pizza, but is coveredwith dozens of erupting volcanoes. Miranda,amoon of Uranus, looks as if it has been smashedto pieces, then put back together again in adifferent way. Saturn’s moon, Mimas has agiant crater, while Europa is a smooth ballmarked with mysterious lines. Just possibly,there may be liquid water beneath Europa’s icy

Dirty snowballsComets are really large‘dirty snowballs’ made ofice and dust. Sometimeswe may be lucky enoughto see them in our nightskies. They have long‘tails’ made of gas anddust swept back by theSun’s rays. Some of thetiny fragments thatescape from cometsfrequently come nearEarth. Known asmeteors, or shootingstars, they appear assplit-second streaks oflight in the night sky.

Rock fragmentsLying between Mars andJupiter is a belt made upof tens of thousands ofpieces of rock. Some area few hundredkilometres in diameter,but most are tiny. Theyare called asteroids.Sometimes they collidewith one another,sending fragments out inall directions. Some ofthese fragments maycome near Earth, and canfall through the air ontothe ground or into thesea. They are calledmeteorites.

Triton

Mimas

Miranda

Europa

Callisto

Io

Ganymede

Comet

Asteroids

The greatest voyageIt would take years for a spacecraft to travelto the giant planets like Jupiter and Saturn.For people, such a mission would be a longand dangerous journey. So a number ofunmanned space probes have been launchedto explore more distant parts of the SolarSystem. The first was Pioneer 10, which leftfor Jupiter in 1972.The greatest journey by a space probe was

undertaken by Voyager 2.Between 1979and 1989 it flew close by Jupiter, Saturn,Uranus and Neptune, sending back amazinglyclear pictures of those planets and theirmoons.Both Pioneer and Voyager probes are

heading out of the Solar System, althoughscientists can still remain in contact withthem. In case aliens should one day comeacross them, these probes carry messagesfrom Earth. Pioneer 10 has an engravedplaque with pictures of humans on it, and adiagram showing Earth’s position in the SolarSystem. Voyager 2 carries an audiovisual discfeaturing ‘Sounds of Earth’, which includessounds of whales, a baby crying and greetings

Clustered in spaceThe Milky Way Galaxy(see page 14)is avast, spiral-shaped collection of billions ofstars, including our Sun and its family ofplanets. It is quite similar in shape and size toanother galaxy just visible in the constellationof Andromeda. Both are accompanied byseveral smaller galaxies oval or irregular in

Deep space mobile

Space telescopeThe Hubble Space Telescopeis a kind ofsatellite, travelling round Earth. Scientists canpoint it towards any part of space and receiveclear pictures of distant stars that are farbetter than any taken from Earth. This isbecause Earth-based telescopes have heat,cloud and other disturbances in theatmosphere to contend with. The Hubble isso powerful it could detect light from a tinytorch 400,000 kilometres away!

Massive explosionStars much more massive than the Sun willend their days somewhat sooner, perhapslasting ‘only’ 10 million years. But they willgo out with a bigger bang! Having swollen tobecome a red supergiant (like Betelgeuse inthe constellation of Orion), the massive star isblasted apart in a colossal explosion, called asupernova by astronomers. The Crabnebula in the constellation of Taurus is theremains of a supernova that was seen about950 years ago by Chinese skywatchers. Thisgas and dust cloud is still expanding.

Glowing ringWhen the Sun runs out of fuel, it will swell upto become a red giant, perhaps a hundredtimes its present size. Eventually the outerlayers will flake away into space. All that willbe left of the Sun is a luminous ring ofglowing gas, called a planetary nebulabyastronomers, and a tiny core, known as awhite dwarf. But don’t worry—it won’thappen for another five billion years!

Nothing can escapeAfter a supernova, the old star’s core may beso dense that it collapses in on itself. The coremay shrink to a tiny point, surrounded by aregion of space where gravity is so strong thatnothing, not even light, can escape from it.Scientists call these places black holes.Ablack hole may also form in the centre of agalaxy. In some galaxies, they are the scene ofviolent activity as stars and gas clouds aresucked into them. The incredible energyblasts huge jets of gas out into space.

Icy wanderersComets are lumps of ice and rock measuringonly a few kilometres across, but with tails ofgas and dust stretching for hundreds ofmillions of kilometres into space (see page8).We know that comets travel round theSun, sometimes with very long, oval-shapedorbits, but nobody knows where they camefrom originally. Some astronomers believethere is a gigantic cloud of such small icybodies surrounding the Solar System deep

Voyager 2space probe

Milky WayGalaxy

Helix nebula(a planetary nebula)

Crabnebula

Black hole

Comet

Hubble SpaceTelescope

BrightestThe brightest stars areshown as the largestspots on these charts.In order of brightness,they are:

1 Sirius2 Canopus3 AlphaCentauri

4 Arcturus5 Vega6 Capella7 Rigel8 Procyon9 Achernar10 Hadar11 Altair12 Betelgeuse

Nearest starsThe first people from Europe to

see the southern hemisphere skieswere explorers, sailing the southern

Atlantic and Pacific Oceans. To constellations theyhad never seen before they gave new names such asThe Painter (Pictor), The Crane (Grus) and TheDove (Columba). The constellation ofCentaurus,the Centaur, contains the neareststars to Earth apart from the Sun: ProximaCentauri and Alpha Centauri (the nearest visible).They are ‘only’ 4.2 light years away—a mere 40trillion kilometres! You can also see one of thenearest galaxies to our own, the Large Magellanic

This chart shows the stars youcan see if you live in thenorthern hemisphere. Turn thebook around so the present monthis at the bottom. Then face south at10 pm. You should then be able to locatemany of the stars on the chart.

This chart shows the stars you can see ifyou live in the southern hemisphere. Turnthe book around so the present month is atthe bottom. Then face north at 10 pm. Youshould then be able to locate many of thestars on the chart.

Canis Major(Great dog)

Scorpius(Scorpion)

Centaurus(Centaur)

ANTLIA

APUS

AQUARIUS

AQUILA

ARA

CANIS MAJOR

CAPRICORNUS

CARINA

CENTAURUS

CETUS

CIRCINUS

COLUMBA

CORONAAUSTRALIS

CORVUS

CRATER

CRUX

DORADO

ERIDANUS

FORNAX

GRUS

HOROLOGIUM

HYDRA

HYDRUS

INDUS

LEPUS

LIBRA

LUPUS

MENSA

MICROSCOPIUM

MONOCEROS

MUSCA

OCTANS

OPHIUCHUS

ORION

PAVO

PHOENIX

PICTOR

PISCES

PISCISAUSTRINUS

PUPPIS

PYXIS

RETICULUM

SAGITTARIUS

SCORPIUS

SCULPTOR

SCUTUM

SERPENSCAUDA

SEXTANS

TRIANGULUMAUSTRALE

TUCANA

VELA

VIRGO

VOLANS

Sirius

Canopus

Large MagellanicCloud

Alpha Centauri

Rigel

Achernar

Hadar

Betelgeuse

Procyon

Legends in the skies

PEOPLE have always been fascinated by thestars of the night sky. Many years ago,

astronomers grouped the stars together intopatterns, imagining their shapes to look likepeople and animals from popular legends. Orionthe hunter, for example, is an easy constellationto spot. Three stars almost in a row make up hisbelt, while others trace the pattern of his daggerand shield. Following at his heels is CanisMajor (the Great Dog) which includes Sirius orthe ‘Dog Star’, the brightest star in the night sky.These two constellations can be seen from bothnorthern and southern hemispheres.

The pattern of constellations can help us tofind and name stars. For example, the two endstars in Ursa Major(the Great Bear), Merakand Dubhe, point to Polaris, the Pole Star, almostexactly due north.

Orion

Andromeda

Ursa Major(Great Bear)

ANDROMEDATRIANGULUM

ARIES

AQUILA

AURIGA

BOÖTES

CAMELO-PARDALIS

CANCERCANESVENATICI

CANISMINOR

CASSIOPEIA

CEPHEUS

COMABERENICES

CORONABOREALIS

CYGNUS

DELPHINUS

DRACO

EQUULEUS

GEMINI

HERCULES

LACERTA

LEO

LEO MINOR

LYNX

LYRA

PISCES

Galaxy

AQUARIUS

PEGASUS

OPHIUCHUS

ORION

TAURUS

CETUS

MONOCEROS

HYDRA

SEXTANSVIRGO

SERPENSCAUDA

SERPENSCAPUT

SCUTUM

URSA MAJOR

URSAMINOR

VULPECULA

Arcturus

Vega Capella

Procyon

Altair

Betelgeuse

Merak

Dubhe

Aldebaran

Pleiades

Polaris

Sideways onSeen from the side, our galaxylooks like two fried eggs back toback. The bulge (or ‘yolks’) inthe middle is called the nucleus.The disc (or ‘whites’) is made ofthe arms that spiral out from thenucleus. The nucleus is a mass ofold red and yellow stars, whilethe arms are rich in dust and gasin which new, blue stars areforming. Our Sun is just overhalfway out from the centre.

Nucleus

Spiral armsPosition of Sun

Giants and dwarfsStars can be of widely varyingsizes and colours. The oldeststars are swollen, red giants.Betelgeuse(in theconstellation of Orion) is a redsupergiant. Old stars are muchbigger—and cooler—than young,blue ones like Rigel(also inOrion), even though Rigel is 40times bigger than the middle-aged Sun. A white dwarf, thecollapsed core of an old star, is,however, tiny when compared to

Milky Way

ONACLEAR, dark night, youshould be able to make out a faint,

luminous band reaching right across thesky. It is our side-on view of part of ourgalaxy, a gigantic spiral of stars, gas anddust revolving in space. It is known as theMilky Way Galaxyafter the misty trailwe can see. In fact, every star you see inthe night sky (and billions more besides)belongs to the Milky Way.

A very few points of light in the skyare not stars in our galaxy, but othergalaxies that lie many billions ofkilometres away from us. They, too, arecollections of billions of stars. In fact,there are billions more galaxies in space,all making up what we call the Universe.

A white dwarf

Betelgeuse

Rigel

Sun

Sun

IndexAAchernar 13Aldebaran 12-13aliens 10Alpha Centauri 13Altair 12-13Andromeda 10, 12Andromeda Galaxy 10, 12Arcturus 12-13asteroids 2-3, 8-9

BBetelgeuse 11, 12-13, 14black hole 11

CCallisto 8-9Canis Major 12-13Canopus 13Capella 12-13Centaurus 13Charon 7Columba 13comets 3, 8, 11constellations 12-13Crab nebula 11craters 4-5, 8

DDubhe 12

EEarth 3, 4-5, 6, 9, 10atmosphere 6, 10internal layers 6statistics 6

eclipse, lunar 4-5eclipse, solar 4-5Europa 8-9

Ggalaxies 10-11, 13galaxy 10, 12, 14-15

nucleus 15side-on view 15spiral arms 14-15

Galaxy, Milky Way 10, 14-15

Galileo space probe 3Ganymede 8gravity 11Great Bear seeUrsa MajorGreat Red Spot 6Grus 13

HHadar 13Halley’s Comet 3Helix nebula 11Hubble Space Telescope 10

IIo 8-9

JJupiter 3, 6-7, 8, 10moons 8-9statistics 6storms on 6

LLarge Magellanic Cloud 13

MMars 3, 6landscape 6life on 6

Merak 12Mercury 3, 6, 8statistics 6

meteorites 5, 9meteors 8Milky Way 10, 14-15Mimas 8-9Miranda 8-9Moon 4-5

mare 5orbit of 4-5phases 4statistics 5surface of 4-5

moons 6-7, 8-9

NNeptune 2, 7, 8, 10moons 8statistics 7winds on 7

OOlympus Mons 6Orion 11, 12, 14

PPictor 13Pioneer 10 space probe 3, 10planetary nebula 11planets 2-3, 6-7, 8, 10orbits 2-3

Pleiades 12Pluto 2-3, 7, 8moon 7statistics 7

Polaris (Pole Star) 12Pole Star seePolarisProcyon 13Proxima Centauri 13

Rred giant stars 11, 14red supergiant stars 11, 14Rigel 13, 14rings, planetary 7

Ssatellite 10Saturn 2, 7, 8, 10moons 8rings 7statistics 7

Scorpius 13shooting stars 8Sirius 12-13Solar System 2-3, 6, 8space probes 2, 3, 10stars 2, 7, 10-11, 12-13,14-15brightest 13different colours 14-15nearest 13northern hemisphere 12oldest 14sizes 14southern hemisphere 13

Sun 2-3, 4-5, 6-7, 10-11,14-15statistics 7temperature 7

supernova 11

TTaurus 11telescope 10Triton 8

UUranus 2, 7, 8, 10angle of spin 7moons 8rings 7statistics 7

Ursa Major (Great Bear) 12

VVega 12-13Venus 2, 6statistics 6

volcanoes 6, 8Voyager 2 space probe 2, 10

Wwhite dwarf star 11, 14

KINGFISHERAn imprint of Larousse plc

Elsley House, 24-30 Great Titchfield Street,London W1P 7AD

First published by Kingfisher 199710 9 8 7 6 5 4 3 2 1

Copyright © 1997 Orpheus Books Ltd

All rights reserved. No part of this publication may be reproduced, stored in a retrievalsystem or transmitted by any means, electronic, mechanical, photocopying or otherwise,

without the prior permission of the publisher.

A CIP catalogue record for this book is available from the British Library.

ISBN 0 7534 0165 7

Created and produced by Orpheus Books Ltd

Text and design:Nicholas HarrisIllustrator:Sebastian Quigley (Linden Artists)

Consultant:Iain Nicolson, Visiting Fellow, Department of Astronomy,University of HertfordshireProduction:Joanna Turner

Printed and bound in Singapore