ES 8. Recognize that gravity is a force that pulls all things on and near the earth toward the center of the earth.
Gravity plays a major role in the formation of the planets, stars, and solar system and in determining their motions.
1. The force of gravity is responsible for the formation of our solar system and other galaxies in the universe.
2. Gravity is a force that pulls all things on Earth towards the center of the Earth.
3. Gravity is responsible for keeping Earth’s atmosphere on Earth, and prevents it from floating away into space.
4. Some objects in the solar system do not have an atmosphere (Earth’s moon) and others have a thin atmosphere (Mercury) because of weak gravitational force.
5. Mercury lost most of its atmosphere for two reasons: A) Mercury is a small planet (small mass) therefore its gravitational force is weak. B) It is the closest planet to the sun, therefore the gas molecules heat up, move far apart, and move even further away from Mercury’s gravitational force. The gases float away into space.
6. Gravity plays a major role in the formation of planets, stars, solar systems, moons, and other objects in the universe.
7. The gravitational force of the sun determines the motions of the planets, dwarf planets, and other objects of our solar system.
Check for Understanding:
1. What is responsible for the formation of the universe and our solar system?
2. Why do planets or natural satellites that have a weak gravitational force lack an atmosphere or have a thin atmosphere? Give an example.
3. What is responsible for the motion of planets, dwarf planets, meteoroids, asteroids, and comets?
What is a black hole?
How is a black hole created?
What would happen to you if you fell into a black hole?