The Sun

Eric AngatTeacher

Essential Question

How does the Sun produce energy and how does it affect us and our planet?

The Sun• The Sun is the center of the Solar system

( Heliocentric).

• The Sun is powered by Nuclear Fusion.

• Hydrogen is the fuel of the Sun.

• Sunlight powers photosynthesis.

• Photosynthesis provide us food and oxygen.

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1.Where is our Sun found in the universe?

2.What is the Milky Way Galaxy?

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3. How are we protected from solar radiation?

Earth’s Geomagnetic Field is protecting us.

Solar WindSolar flare

Effects

4. How does nuclear fusion happen?

5. How long does it take for sunlight to reach us?

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Nuclear Fusion powers the Sun and all other stars. This happens in the Sun’s core.

Hydrogen or H is the fuel of stars.

Sunlight as energy.

Helium as by product

Neutrino as by product

Sunlight takes 8 minutes and 20 seconds to reach Earth. Sunlight travel through space in the form of electromagnetic wave.

Nuclear FusionNuclear Fission

http://www.weather.gov.hk/education/dbcp/pow_stat/eng/r5.htm

Worldwide nuclear power plants near earthquake zones. Fuel: Uranium

Powers the stars and nuclear bombs.Fuel: Hydrogen

Atomic Bomb dropped in Horoshima and Nagasaki, Japan

Nuclear Bomb tested 450 x or more stronger than the atomic bomb.

6.How is Nuclear fission different from Nuclear fusion?

7. What will happen to the Solar system when the Sun runs out of fuel?

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8. How did we learn about the composition of the Sun?

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Every chemical element has its own spectrum. This spectrum is like a “fingerprint” for the element.Each star will produce a different spectrum. Scientist can tell from the dark lines in the spectrum which elements are present in the star’s atmosphere. The Sun’s spectrum shows dark lines that represent absorbed light from the elements hydrogen and helium.

9. How big, bright, hot is the Sun compared to other stars in the known universe?

The Hertzsprung-Russell diagram 

Luminosity means how bright.

Temperature means how hot. X

Y

10. How do plants and animal use sunlight as a source of energy?

a. Plants use sunlight for photosynthesis to produce food.

b. Human being use sunlight to make their bones strong.

Solar energy is converted to chemical energy or food through photosynthesis

11. How is solar energy so important to the life on Earth?

a.Because light enables living things to see.b.Because light travels through space in the

form of electromagnetic waves.c.Because plants are producers of food and

need sunlight for photosynthesis.d.Because light makes our bones and teeth

strong.

All of the choices are true but which of them answers the question?Plants need light for photosynthesis and produce food.

Sunlight is used as energy for photosynthesis

Without plants we do not have oxygen and food.

12. Why do green plants require solar energy?

A. to produce their food through photosynthesis.B. to absorb nitrogen.C. to release carbon dioxide into the atmosphere.D. to decompose the dead or decaying remains of animals.

13. Which describes the difference between nuclear fission and nuclear fusion?

A. Nuclear fission is the process that produces the radiant energy of stars, and nuclear fusion splits a heavier nucleus into smaller nuclei.

B. Nuclear fission splits a heavier nucleus into smaller nuclei, and nuclear fusion is the process that produces the radiant energy of stars.C. Nuclear fission produces the energy in the core of Earth, and nuclear fusion produces energy in nuclear power plants.D. Nuclear fission produces energy in nuclear power plants, and nuclear fusion produces the energy in the core of Earth.

Radiation moves energy without any help from matter.

Sunlight travel in space in the form of electromagnetic radiation

14. How do solar energy travel through space?

a.convectionb.radiationc.conductiond.insulation

15. Which of the following chemical reactions produce the sun’s energy? A. Helium nuclei are combined by nuclear fusion. B. Oxygen is present to cause combustion of solar fuel molecules. C. Hydrogen nuclei combine through nuclear fusion into helium. D. Helium and oxygen break down through nuclear fission.

16. How is solar energy essential to plants? A. Solar energy maintains the internal

temperature of the plants. B. Solar energy is converted to

chemical energy used by the plants. C. Solar energy signals the plants to

release leaves in the fall. D. Solar energy regulates the

consumption of oxygen by the plant.

17. How does the sun’s energy affect food webs on Earth? A. The ultraviolet radiation of the sun generates

ozone for plants to support all life. B. The wavelengths of visible light stimulate

plant cells to produce energy compounds by photosynthesis.

C. The microwaves emitted by the sun stimulate animal reproduction in the rainforest.

D. The infrared radiation reflected from the Earth’s surface drives the carbon, oxygen, and nitrogen cycles.

http://www-bioc.rice.edu/pblclass/6th%20grade/astronomy/star%20life.pdf

Our sun in an average star.

Stars are born in a region of high density

Nebula, and condenses into a huge globule of gas and dust and contracts under its own gravity.

nebulais a cloud of dust and gas, composed primarily of hydrogen (97%) and helium (3%)..

http://sunshine.chpc.utah.edu/labs/star_life/starlife_proto.html

Scientists believe that new stars form inside of nebulas

Makes life on our planet possible by giving us great amounts of light and heat.

Is just a medium sized star (yellow dwarf). It is about 1.4 million kilometers in diameter.

Is the center of our Solar System (HELIOCENTRIC). All the planets and other objects orbit around it.

made up mostly of hydrogen.

Contains dark spots that are known as sunspots. http://www.frontiernet.net/~kidpower/

sun.html

The Sun is by far the largest object in the solar system. It contains

more than 99.8% of the total mass of the Solar System (Jupiter contains most of the rest).

The Sun's outer visible layer is called the

photosphere

The region immediately above the photosphere is called the

chromosphere.

chromosphere

http://genesismission.jpl.nasa.gov/science/mod3_SunlightSolarHeat/SolarStructure/

coronaVisible during total eclipse of the Sun, when for a few minutes the Moon completely covers the Sun's face, a glow appears around the darkened Sun--the solar corona, the Sun's outermost atmosphere.

http://www-istp.gsfc.nasa.gov/Education/wcorona.html

sunspot

A sunspot is a region on the Sun's surface (photosphere) that is marked by a lower temperature than its surroundings and has intense magnetic activity.

solar prominence

is a large bright feature extending outward from the sun's surface, often in a loop configuration.

http://en.wikipedia.org/wiki/Image:Solar_prominence_1.jpg

The smallest of the loop prominences shown here is over three times bigger than the Earth .

Flare (Solar) Rapid release of energy from a localized region on the Sun in the form of electromagnetic radiation, energetic particles, and mass motions.

What impact do solar flares have on human activities?

Solar flares produce high energy particles and radiation that are dangerous to living organisms. However, at the surface of the Earth we are well protected from the effects of solar flares and other solar activity by the Earth's magnetic field and atmosphere. The most dangerous emissions from flares are energetic charged particles (primarily high-energy protons) and electromagnetic radiation (primarily x-rays).

SOLAR WINDThe solar wind is a continuous stream of ions (electrically charged particles) that are given off by magnetic anomalies on the Sun.

The comet’s tail form because of the solar wind.

black hole An area of dense, invisible matter in space. The gravitational attraction is so large in this that anything that enters will not escape.

The Sun, like most other astronomical objects (planets, asteroids, galaxies, etc.), rotates on its axis. Unlike Earth and other solid objects, the entire Sun doesn't rotate at the same rate. Because the Sun is not solid, but is instead a giant ball of gas and plasma, different parts of the Sun spin at different rates.

What are black holes?Have you ever had to vacuum your bed room? When you do, watch closely because you will see the dirt, and crumbs start to move towards the vacuum cleaner.  A black hole is similar to a vacuum cleaner, cleaning up debris left behind in outer space.

In the universe, most stars occur in groups of at least two stars. Two stars that are locked in elliptical orbit around their center of mass (their barycenter) are called a

binary star system. About half of all stars are in a binary star system.

WHY DO STARS TWINKLE? The scientific name for the twinkling of stars is stellar scintillation (or astronomical scintillation). Stars twinkle when we see them from the Earth's surface because we are viewing them through thick layers of turbulent (moving) air in the Earth's atmosphere.

WHAT IS THE CLOSEST STAR?The closest star to us is the sun! Other than that, the closest star

is Proxima Centauri. Proxima Centauri is 4.3 light-years from the Sun. It has an absolute magnitude of 15.5

WHY ARE STARS HOT AND BRIGHT?

Nuclear fusion. Stars are giant nuclear reactors. In the center of stars, atoms are taken apart by tremendous atomic collisions that alter the atomic structure and release an enormous amount of energy. This makes stars hot and bright.