1. Our Solar System SC.E.1.2.4, SC.E.1.2.5 Earth and Space

2. Our Solar System Our solar system is made up of our Sun, along with the planets and all the other objects that orbit around it.

3. Our Solar System A planet is a large, nearly spherical (round) body in space that orbits in a cleared path around a star. All eight of the planets in our solar system orbit around the Sun. – Orbit: the path the planets take around the sun to complete a revolution. – Gravity is one of the forces that keep the planets in orbit. The Earth’s orbit Sun Orbit is the path the planet takes around the Sun

4. Our Solar System Ellipse: flattened, oval shape of the orbit. Sun Ellipse is the shape of the path (orbit) the planet takes around the Sun The ellipse

5. Our Solar System The amount of time it takes each planet to make one revolution around our Sun depends on how far the planet is from the Sun. Revolution: one complete path of a planet on its orbit. It takes the Earth 365 ¼ days to complete one revolution. That is why we have 1 year. The farther away the planet is from the Sun, the longer it takes to complete one revolution (therefore, the length of a planet’s year, which is one revolution around the Sun, varies from planet to planet). Start (Day 1) Finish (Day 365 ¼) One complete revolution around the Sun Sun Revolution one complete path (orbit) the planet takes around the Sun

6. Our Solar System All of the planets rotate on their axes. – Axis: imaginary line that runs through a planet on which it rotates (turns) on. – Rotation: one complete turn of a planet on its axis. – The length of the day, or time the planet takes to rotate, also varies from planet to planet. On Earth it takes 24 hours for one complete rotation. Rotation is one complete turn of a planet on its axis

7. Our Solar System The Inner Planets – Mercury, Venus, Earth, and Mars. They are small and rocky

8. Our Solar System Mercury (closest to the Sun) – The closest to planet to the Sun. – Its surface is very hot, and it has many craters, like Earth’s moon. Venus (2nd from the Sun) – The second planet from the Sun. – Its surface is very hot. – Its atmosphere is mostly carbon dioxide. – It has volcanoes on its surface similar to those found on earth.

9. Our Solar System Earth (3 rd from the Sun) – The third planet from the Sun. – The only planet in our solar system where life has been found. – There is water on Earth’s surface and its atmosphere contains gases that support life. – Without the blanket of gases that cover Earth, humans would not be able to live on Earth.

10. Our Solar System Mars (4 th planet from the Sun) – Also known as the red planet. – Mars’s red color comes from the rust-like substances on its surface. – The surface of Mars is very cold. – There is some evidence that water once flowed over the surface of Mars.

11. Our Solar System The Outer Planets – Jupiter, Saturn, Uranus, and Neptune. The outer planets are large and made mostly of gas. JupiterSaturnUranusNeptune

12. Our Solar System Jupiter (5 th planet from the Sun) – Largest planet in our solar system. – Its outer layer are made up of swirling gases. – Jupiter’s atmosphere is very colorful and it has an are called the Great Red Spot. This spot is a storm that has been raging from hundreds of years and is three times larger than Earth in diameter. – A second red spot, about half the size of the Great Red Spot, has recently formed as well. – Jupiter also has thin dark rings that are not easily observed.

13. Our Solar System Saturn (6 th planet from the Sun) – The second largest planet in our solar system. – Saturn is made up of swirling gases. – Saturn is best known for its large system of rings, each made up of countless tiny bits of ice and rock.

14. Our Solar System Uranus (7 th planet from the Sun) – Has an atmosphere that includes green gases and frozen water. – It has rings, but far fewer than Saturn. – The axis of Uranus is so tilted that the planet rotates on its side!

15. Our Solar System Neptune (farthest (8 th )planet away from the Sun) – It is similar to Uranus except that is does not have as much of a ring system and does not rotate on its side.

16. Our Solar System Dwarf Planets – In the summer of 2006, astronomers reclassified Pluto and some other bodies in our solar system as dwarf planets. – Pluto is small and rocky, and it has much in common with comets. – The smallest dwarf planet in our solar system is Ceres. It is located in the asteroid belt.

17. Our Solar System The Asteroid Belt – Asteroids are large chunks of metal or rock that orbit the sun in a belt, or region of the solar system. – There are thousands of them. – Most are found between planets Mars and Jupiter.

18. Our Solar System About 9 football fields Asteroid impact to the Earth

19. Our Solar System Trick to help you remember the order of the planets in our solar system. My Very Eccentric Mother Just Served Us Nine Pizzas ERCURYERCURY ENUSENUS ARTHARTH ARSARS UPITERUPITER ATURNATURN RANUSRANUS EPTUNEEPTUNE LUTOLUTO

20. Our Solar System http://video.nationalgeographic.com/video/player/science/space- sci/exploration/voyager-sci.html Video Solar System Exploration