1. Solar System

2. The Sun Closest star to Earth Yellow star
Medium in size compared to the other stars
About 4.6 billion years old
More than 1 million Earths could fit inside it
Central body of our solar system
Main source of energy for Earth
Essential to life on this planet

4. Energy from the Sun Made mostly of hydrogen and helium
The Sun’s energy comes from nuclear fusion
Nuclear fusion – changes hydrogen to helium
Only one-fourth as dense as Earth (Earth is a rocky planet)
Temperature on surface is 5,500 degrees Celsius (9,932 Fahrenheit)
Temperature at the core about 15,000,000 degrees Celsius

6. The Sun’s Effect on Earth’s Energy
Sun is the main source of energy on Earth
Solar radiation provides heat to keep Earth warm and livable
Ocean and
atmosphere help
moderate
temperatures

7. The Sun’s Effect on Earth Food
Photosynthesis – plants use sunlight to produce food (producers)
When a consumer eats a plant the energy is transferred to the animal
The sun is the energy source for nearly all living things

8. The Sun’s Effect on Earth Winds
Winds form because of the sun
Winds blow from regions of high air pressure to low air pressure
Differences in air pressure form because of the Sun’s uneven heating of Earth’s surface

9. The Sun’s Effect on Earth Water Cycle
Drives the water cycle
Causes water on Earth’s surface to evaporate

10. Life Cycle of a Star
Nebula - All stars start from enormous rotating clouds of dust and gasses – mostly hydrogen
Protostar – the nebula collapses into a very dense mass
Main-Sequence Star – When a newly formed star stabilizes, this stage can last billions of years, our Sun is in this stage

11. Life Cycle of a Star
Red Giant – the outer part expands while the core contracts, becomes very bright but cools
Planetary Nebula – the outer layers are released
White Dwarf – over a long period of time the star shrinks, there is no fuel left in its core
Black Dwarf – remaining heat radiates into space until it fades to a black dwarf

12. Life Cycle of a Star

13. Planets – large bodies that orbit the Sun
Galaxy – a huge system of gas, dust and stars
Our solar system is a very small part of a much larger system called the Milky Way galaxy

14. Moons Moon – a natural satellite orbiting around another body in space
About 140 moons in our solar system
Earth’s Moon
Diameter of 3,476 km – four times smaller than Earth
Rotates on an axis and revolves around Earth
One month for the Moon to make a complete rotation
Reflects the light from the sun
Phases are produced by the alignment of the Moon and the Sun in the sky.

15. Phases of the Moon

16. Asteroids Relatively small, rocky object that orbits the sun
Most orbit in a band called the asteroid belt between Mars and Jupiter

17. Comets A small, orbiting body made of dust, ice, and frozen gases.
When a comet approaches the sun, frozen solids vaporize
Gases and dust are released, producing a glowing region called a coma
Charged particles push out of the coma, producing a glowing tail
Some comets can take 30 million years to orbit the Sun

18. Meteoroids/Meteors
Meteoroids – bits of rock or metal that orbit the sun
Meteor – a meteoroid that enters Earth’s atmosphere and is heated by friction with the air
For a few moments, they burn as they fall, appearing as streaks of light against the sky
Also called falling/shooting stars

19. Inner Planets Mercury Venus
Closest to sun, extremely hot (800 degrees) and cold (-343 degrees)
Cratered surface due to collisions with asteroids
Venus
Second planet from the sun
Covered by thick, poisonous clouds
Pressure would crush your bones
Almost the same size as Earth
Temperatures hot enough to melt lead

20. Inner Planets Earth Only planet known to have liquid water
Largest inner planet
Mars
Red planet, may have once had liquid water

21. Inner Planets
Mars
Photo from Mars Rover
Earth
Venus
Mercury

22. Outer Planets Jupiter Fifth planet from the sun
One of the brightest object in the sky
Winds can reach up to 400mph
Famous for its Great Red Spot – storm system
Has many moons and rings
Saturn
Sixth planet from the sun
Known for its rings – made mostly of ice particles
Least dense - Saturn would float in water

23. Jupiter
Saturn

24. Outer Planets Uranus Seventh plant from the sun
Has at least 27 moons and 11 rings
Neptune
Eighth planet
Winds can reach 1,500 mph
At least 11 moons
Pluto
Classified as a dwarf planet in 2006
3 moons

25. Gravity
Gravitation is an attractive force between objects that have mass
It is weak unless the masses involved are very large (like Earth)
Gravity causes objects to speed up as they fall
Acceleration due to gravity at Earth’s surface is about 9.8 meters per second per second
Air resistance, or drag, will slow a falling object

26. Planets Orbiting the Sun
Just like we are pulled to Earth because it has a greater mass than us – The sun has a greater mass than the Earth which pulls the planet keeping it in orbit around it

27. Astronomers Astronomer – a scientist who studies outer space
Famous Astronomers
Copernicus – reasoned that the sun is at the center of the solar system
Galileo – the first person to use a telescope