1. The Sun: A Medium-sized StarSunThe Sun: A Medium-sized StarSun

2. Learning Goals  I will be able to describe the make up of the sun.  I will be able to explain the sun’s role in the survival of things on earth.  I will be able to describe the make up of the sun.  I will be able to explain the sun’s role in the survival of things on earth.

3. The Sun  star at centre of Solar System.  warms our planet and provides light and thermal energy.  Processes, or reactions, occurring inside our Sun provide this energy.  very important to life on Earth.  star at centre of Solar System.  warms our planet and provides light and thermal energy.  Processes, or reactions, occurring inside our Sun provide this energy.  very important to life on Earth.

4. Layers of the Sun  composed of many different layers, with each layer performing different activities.  layers composed of gases.  no solid surface like Earth, but it does have a definite structure.  composed of many different layers, with each layer performing different activities.  layers composed of gases.  no solid surface like Earth, but it does have a definite structure.

5. The Core  nuclear reactions occur that change the composition and energy of atomic nuclei.  Atoms of hydrogen (H) fuse, or join, to form atoms of helium (He).  These nuclear reactions release immense amounts of energy, causing the Sun’s core to reach temperatures of about 15 million °C.  nuclear reactions occur that change the composition and energy of atomic nuclei.  Atoms of hydrogen (H) fuse, or join, to form atoms of helium (He).  These nuclear reactions release immense amounts of energy, causing the Sun’s core to reach temperatures of about 15 million °C.

6. From the Core to the Atmosphere  Energy produced in core moves outward into the next layer, the radiative zone.  The energy moves outward into the convective zone, where cool matter sinks and hot matter rises.  Photosphere: Suns surface where energy escapes as light.  Atmosphere: is divided into the chromosphere and the corona.  Chromosphere: inner atmosphere, very hot—about 60 000 ºC hotter than the photosphere!  Cornona: The thin outer layer that glows brilliantly.  It extends millions of kilometres into outer space.  Energy produced in core moves outward into the next layer, the radiative zone.  The energy moves outward into the convective zone, where cool matter sinks and hot matter rises.  Photosphere: Suns surface where energy escapes as light.  Atmosphere: is divided into the chromosphere and the corona.  Chromosphere: inner atmosphere, very hot—about 60 000 ºC hotter than the photosphere!  Cornona: The thin outer layer that glows brilliantly.  It extends millions of kilometres into outer space.

7. The Sun’s Surface FeaturesSurfaceFeaturesThe Sun’s Surface FeaturesSurfaceFeatures  Sunspot: dark region of cool matter on the photosphere, caused by twists in the Sun’s magnetic field.  vary in both size and regularity.  Often, sunspots appear in pairs of opposite polarity.  Solar flare is a huge explosion of gas and charged particles  Often found near sunspots,  release huge amounts of energy  can reach temperatures of tens of millions of degrees Celsius.  Sunspot: dark region of cool matter on the photosphere, caused by twists in the Sun’s magnetic field.  vary in both size and regularity.  Often, sunspots appear in pairs of opposite polarity.  Solar flare is a huge explosion of gas and charged particles  Often found near sunspots,  release huge amounts of energy  can reach temperatures of tens of millions of degrees Celsius.

9. Energy from the Sun  Every second, the Sun releases enough energy to meet the needs of every person on Earth for the next 500 000 years.  The Sun is the driving force behind Earth’s climate and weather and also provides the energy needed for life to exist on Earth Plants use sunlight to grow and to produce food. Animals eat plants that are grown in sunlight. Coal formed from the remains of prehistoric plants; form of stored energy from the Sun. Oil formed from fossils, which obtained energy from plants, and hence, the Sun.  Every second, the Sun releases enough energy to meet the needs of every person on Earth for the next 500 000 years.  The Sun is the driving force behind Earth’s climate and weather and also provides the energy needed for life to exist on Earth Plants use sunlight to grow and to produce food. Animals eat plants that are grown in sunlight. Coal formed from the remains of prehistoric plants; form of stored energy from the Sun. Oil formed from fossils, which obtained energy from plants, and hence, the Sun.

10. The Auroras  The Sun’s corona is constantly releasing electrically charged particles into space at speeds of up to 400 km/s.  travelling particles are known as the solar wind.  Earth’s atmosphere contains atoms of different gases.  Earth surrounded by magnetic field.  Particles of solar wind spiral along the lines of the magnetic field.  As the particles move toward the poles and strike the gases in Earth’s atmosphere, a light display called an aurora is produced.  Known as the Northern Lights  The Sun’s corona is constantly releasing electrically charged particles into space at speeds of up to 400 km/s.  travelling particles are known as the solar wind.  Earth’s atmosphere contains atoms of different gases.  Earth surrounded by magnetic field.  Particles of solar wind spiral along the lines of the magnetic field.  As the particles move toward the poles and strike the gases in Earth’s atmosphere, a light display called an aurora is produced.  Known as the Northern Lights

11. Learning Goals Revisited  I will be able to describe the make up of the sun.  I will be able to explain the sun’s role in the survival of things on earth.  I will be able to describe the make up of the sun.  I will be able to explain the sun’s role in the survival of things on earth.

12. Complete 1.Where do the Sun’s nuclear reactions take place? 2.Create a graphic organizer describing light’s journey from the core of the Sun to Earth. 3.How are solar flares different from sunspots? 4.Describe how the Sun indirectly powers gasoline-powered automobiles. 5.The Sun produces more than enough energy to meet our needs. Suggest ways we could use the Sun’s energy more effectively. 6.How would you explain to a friend how an aurora forms? 1.Where do the Sun’s nuclear reactions take place? 2.Create a graphic organizer describing light’s journey from the core of the Sun to Earth. 3.How are solar flares different from sunspots? 4.Describe how the Sun indirectly powers gasoline-powered automobiles. 5.The Sun produces more than enough energy to meet our needs. Suggest ways we could use the Sun’s energy more effectively. 6.How would you explain to a friend how an aurora forms?