Exploring Gravity in Our Solar System

1. SPI 0807.12.6 Gravity and Celestial Motion Science Notes Tennessee SPI Objective: Illustrate how gravity controls the motion of objects in the solar system. Essential Question(s) 1) What is rotation (spinning)? 2) What is a revolution (orbiting)? 3) How does gravity cause these motions? I Can Statement I can describe the motion of celestial object caused by gravity. Success Criteria I can prove that I understand this topic by diagraming the movements (rotation and revolution) of the Earth and the Sun.

2. Formation of Our Solar System • Gravity is a "pulling" force that causes every particle of matter to be attracted to every other particle of matter • Gravity formed our solar system from a nebula This is called the nebular theory (watch video) • Video Link (3:05): The Nebular Theory

3. Gravity formed our solar system from a nebula • Nebulas are huge clouds of cosmic dust consisting of small particles of matter left over from exploded stars. • Nebulas rotate due to the force of gravity.

4. Gravity formed our solar system from a nebula A) Over time, gravity pulled the particles (atoms and molecules) in the nebula together into clumps.

5. Gravity formed our solar system from a nebula B) Each time another particle was added to a clump by gravity, the mass and gravity of the clump increased. • This enabled each clump to attract even more matter. Mass Increased More Gravity Mass Increased More Gravity Mass Increased More Gravity More Gravity Mass Increased

6. Gravity formed our solar system from a nebula C) Larger clumps had stronger gravity and pulled even more clumps together.

7. Gravity formed our solar system from a nebula D) The gravity from these large clumps pulled in all directions forming a roughly spherical shape. This explains the round (spherical) shape of stars and planets. Earth Jupiter The Sun

8. Gravity formed our solar system from a nebula E) Gravity caused these large clumps to start spinning. This motion is called rotation. This is why the sun, planets, and moons rotate.

9. Gravity formed our solar system from a nebula F) After a huge mass of clumps were pulled together, the gravity caused nuclear fusion to occur, and a new star was “born.” This is how our sun was formed

10. Gravity formed our solar system from a nebula G) Smaller masses of clumps formed into planets and moons. This is how planet Earth was formed

11. Gravity formed our solar system from a nebula Watch these video clips (Write down 3 facts from each video) Link 01 (2:15)Birth of Our Solar System Link 02 (4:27) Formation of Our Solar System

12. Gravity causes our sun and planets to rotate (spin) • Rotation-when an object spins on its axis Gravity causes our planets and moons to revolve (orbit) • Revolution-when an object circles around another object • Gravity keeps Earth, and all the other planets, from “flying off” into space as they revolve (orbit) around the sun. Question: What keeps our planet from falling into the sun? Answer: The inertia (momentum) of the planet’s lateral (sideways) motion as it revolves around the sun.

13. SPI 0807.12.6 Gravity and Celestial Motion Science Notes Motion Demonstration:(need three students) One to be the Sun, One to be Earth, and One to be the Moon • Clear out some space, and position each student • First have each student demonstrate rotation • Then have the Earth and Moon demonstrate revolution • Finally ask all three to rotate while at the same time the Earth and Moon revolve around the sun. Enjoy the laughs!

14. Celestial Motion • The Sun rotates. • The Earth rotates. • The Moon rotates. Motion Demonstration: Show this computer simulation Link: Gravity and Orbits from the University of Colorado • The Earth revolves (orbits) around the sun. • Likewise, the Moon revolves (orbits) around the Earth. 1) You can show the Sun, Earth, and Moon at the same time. 2) You can show the direction of gravity. 3) You can adjust the revolution speed. 4) You can show the orbital paths. 5) Just for Fun: You can “turn off” the gravity. Moon Earth The Sun

15. SPI 0807.12.6 Gravity and Celestial Motion Science Notes • Gravity keeps the moon from “flying off” as it orbitsthe Earth (See Holt Online Ch15: Sect 4 Visual Concepts) Revolution Rotation

16. Review SPI 0807.12.6 Gravity and Celestial Motion Science What is one way gravity helped form our solar system and planets? A) By pushing matter apart B) By pulling matter together What is another way gravity helped form our solar system and planets? A) By making objects revolve and rotate B) By making objects move in straight lines Contrast revolution and rotation. A) Revolve = circling around another object Rotate = spinning on an axis B) Revolving is faster than rotation & has more gravity

17. SPI 0807.12.6 Gravity and Celestial Motion Science Question

18. SPI 0807.12.6 Gravity and Celestial Motion Science Question

19. SPI 0807.12.6 Gravity and Celestial Motion Science Question

20. SPI 0807.12.6 Gravity and Celestial Motion Science Question Wrong!

21. SPI 0807.12.6 Gravity and Celestial Motion Science Question

22. SPI 0807.12.6 Gravity and Celestial Motion Science Notes Brainpop Videos • View the Brainpop video titled “Gravity” • View the Brainpop video titled “Solar System” Link: Brainpop Website User name: (get this from your teacher) Password: (get this from your teacher) Task 01: Write down 5 things that catch your attention as your watch each video. Task 02: Complete the Brainpop quizzes.