Question 5 (2 points)

Why do planets stay in orbit around the Sun?

a	The Sun's light pulls them in.
b	They bounce off other planets.
c	The Sun's gravity pulls them while their motion keeps them moving forward.
d	There is no gravity in space.

Question 6 (4 points)

Use the word bank to complete these fill-in-the-blank sentences.

If gravity were stronger, planets would move and their orbits would become . If gravity were weaker, planets might away from the Sun. Moons stay in orbit around planets because of the planet's .

Word Bank:disappear spin magnetism wider drift gravity smaller slower faster

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Question 7 (4 points)

Use the word bank to complete these fill-in-the-blank sentences.

• The has the strongest gravity and keeps Earth in orbit.
• The orbits around Earth because of Earth's gravity.
• The orbits Earth in low orbit and moves very fast.
• The farther something is from Earth, the gravity pulls on it.

Word Bank:Mars stronger weaker Sun gravity Moon International Space Station (ISS)

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Question 8 (5 points)

In your own words, explain how gravity and motion work together to keep a planet in orbit.

Your answer:

Question 9 (5 points)

Imagine a planet with very little gravity. What would happen to its moons or any objects nearby?

Your answer: