COntents 4-5 THE SUN OUR HEATER How hot Sunny facts Shooting gas A dying star 6-7 SHIFTING LIQUID Liquid and rock A floating crust Tectonic plates 8-9 WARM CLIMATES How hot Hot around the middle Hottest place on Earth 10-11 FIERY ERUPTIONS Lava flow Live volcanoes Calderas 12-13 POMPEII TO EYJAFJALLAJÖKULL Pompeii Eyjafjallajökull 14-15 IN THE GREENHOUSE Greenhouse gases Thinning ozone CFCs Methane 16-17 OUR PLANET Felling forests Polluting gases Melting ice Spreading deserts CHANGES 18-19 WHAT IS HEAT Jumping molecules Rub your hands Heat changes everything The 3 forms of water 20-21 EXTRA HOT Using infrared Cook infrared DonGt touch Microwaves 22-23 MAKING PLANTS GROW Making seeds germinate Blossoms and pollen Photosynthesis 24-25 RIPENING Sweet food Ripening fruits Overripe Door to door Tunnels and greenhouses 26-27 HOT BODIES How hot are you Hot blood Sweating heat Keeping warm 28-29 FIRE AND FLAMES Making fire Making sparks with flints Fire from sunlight 30-31 HOT DESTRUCTION Forest fires Flowers from flames Fire storms
48-49 COOKED FOOD Barbecues and fire pits Medieval spit-roasting Hot spices How yeast works 50-51 DRIED OUT Dried meat Dried flavors Louis Pasteur 52-53 BOOM Nuclear fission Gunpowder Fireworks 54-55 HOT TRANSFORMATION Smelting ore Extruding metal Welding Casting 56-57 MELTING AND MAKING Glassblowing Pottery Hot wax 58-59 HOT AIR Hot air balloons Floating research Chinese signalling lanterns GLOSSARY and INDEX 32-33 PUTTING OUT FLAMES Carbon dioxide Oil well fire Fire planes 34-35 HEATED WIRES Hot wires Power up Dryers Photovoltaic electricity Solar electricity 36-37 HEATING HOMES Hypocaust heating Radiant heating Hot wash Warm home Wrapping up 38-39 COOLING HOMES Fans and punkahs Electric fans Air conditioning Cooling drips Windcatchers 40-41 FOSSIL FUELS Burning coal Oil Geothermal energy 42-43 BIO FUELS Biomass Methane 44-45 HUBBLE BUBBLE Boiling point Elbow heat Thermometers Sterilising 46-47 STEAM Making steam Steam engines Underground steam
4 The Sun Our Heater Our Sun is a medium-sized star called a yellow dwarf It’s at the center of our 8-planet solar system It provides heat and light and life on Earth would not exist without it From a distance it looks like a solid glowing yellow ball But it isn’t solid it’s a ball of gases like every other star The main gases that make up the Sun are hydrogen and helium HOw hOt The Sun gives off an incredible amount of heat At itGs core or center itGs 27 million Fahrenheit F At its surface itGs 9,941 F EarthGs average is 68 F This infrared photo shows flares on the Sun’s surface The heat is caused by particles called atoms of hydrogen gas found in the SunGs core The atoms bang into each other and this changes them into the gas helium This action releases huge energy and creates temperatures of millions of degrees This is what gives the Sun its heat and light Sunny facts of layers of gas around the Equator but is still 93 million miles away The Sun is the closest star to planet Earth It is more than 100 times bigger than Earth Our planet Earth orbits around the Sun the Sun does NOT orbit around Earth The Sun’s average temperature is 10,300 F The Sun is 4 6 billion years old The Sun has no solid surface It is made up
shOOting gas The surface of the Sun may look calm from a great distance away but it is really a fierce bubbling mass of fiery gases that is constantly changing shape It is continuously erupting with prominences and flares Prominences are the bright looping streams of hot gas that arch out into space They may hold their shape for months before collapsing back into the SunGs surface The visible surface of the Sun is called the photosphere prominence The chromosphere is just above the photosphere core The corona is the outer part of the Sun’s atmosphere Solar flares spurt from the surface of the Sun KEY WORDS star solar system hydrogen helium prominence flare white dwarf A dying star Unfortunately the Sun doesnGt have an unlimited amount of hydrogen fuel to convert into heat and light One day it will run out Astronomers have calculated that the Sun has enough hydrogen in its core to last another 7 billion years or so By this time it will have exhausted its reserves and switched to burning helium Then it will stop shining and become a dead star or what is known as a white dwarf
