Gravity in Space

2. Gravity holds the ______ in its orbit around the earth
4. Gravity is one of the four known fundamental ______ in the universe
5. The first person to describe the law of gravity as an interaction between two masses
7. The force of Earth's gravity keeps the Moon from ____ off in a straight line
9. A force of attraction between masses
10. The force of gravity is a zone, or _____, that surrounds a mass
12. Gravitational attraction between masses _____ as the distance between them increases
13. Gravity keeps Earth and other planets in a ______ orbit around the Sun
16. An object in motion will naturally travel in a ____ line forever unless a force changes its direction

1. The minimum speed required for an object to leave orbit is "Escape ______"
2. The strength of the force due to gravity depends on the ____ of both objects
3. The curved path of an object around another object in space
6. Astronauts feel _______ in space because they are in free fall, but falling around Earth
8. The ____ of gravity on Earth's surface is 9.8 m/s/s
11. Newton recognized that the force of gravity is always toward the _____ of mass
14. A force acting on an object moving around abother object, pulling it toward the center is called _____ force.
15. Small masses exert very ______ gravitational force