Exercises: Objects in the Solar System and the Role of Gravity
Name the object at the center of our Solar System. Then state whether it is a planet, a moon, or a star, and tell what it provides to the planets that orbit it.
Name the object at the center of our Solar System. Then state whether it is a planet, a moon, or a star, and tell what it provides to the planets that orbit it.
A student says, "A moon is a small planet that orbits the Sun." Correct this statement by defining what a moon is and giving one example, such as Earth's Moon or…
A student says, "A moon is a small planet that orbits the Sun." Correct this statement by defining what a moon is and giving one example, such as Earth's Moon or Jupiter's moon Europa.
Classify each object as a comet, an asteroid, or a meteor: (a) a streak of light in the night sky as a small piece of rock burns up in Earth's atmosphere, (b) a rocky…
Classify each object as a comet, an asteroid, or a meteor: (a) a streak of light in the night sky as a small piece of rock burns up in Earth's atmosphere, (b) a rocky body found mostly between Mars and Jupiter, (c) an icy body that grows a glowing tail when it gets close to the Sun.
Emma makes a model of the Solar System. She places Mercury, Venus, Earth, and Mars on one side of the asteroid belt and Jupiter, Saturn, Uranus, and Neptune on the other…
Emma makes a model of the Solar System. She places Mercury, Venus, Earth, and Mars on one side of the asteroid belt and Jupiter, Saturn, Uranus, and Neptune on the other side. (a) Which group is made of the inner planets, and which of the outer planets? (b) Describe one physical difference between the two groups, such as size, composition, or number of moons.
Earth orbits the Sun at an average distance of about $150{,}000{,}000$ km, and Neptune orbits at about $4{,}500{,}000{,}000$ km. (a) How many times farther from the Sun…
Earth orbits the Sun at an average distance of about $150{,}000{,}000$ km, and Neptune orbits at about $4{,}500{,}000{,}000$ km. (a) How many times farther from the Sun is Neptune than Earth? (b) Using what you know about gravity, explain why Neptune takes much longer than Earth to complete one orbit.
Jayden reads that the Kuiper belt and the Oort cloud both contain icy objects. Compare the two regions by describing (a) where each is located relative to Neptune and…
Jayden reads that the Kuiper belt and the Oort cloud both contain icy objects. Compare the two regions by describing (a) where each is located relative to Neptune and the Sun and (b) one kind of object that is found there.
Aaliyah says, "If the Sun suddenly disappeared, Earth would keep moving in a circle around where the Sun used to be." Evaluate her claim. In your answer, explain (a)…
Aaliyah says, "If the Sun suddenly disappeared, Earth would keep moving in a circle around where the Sun used to be." Evaluate her claim. In your answer, explain (a) what force keeps Earth in orbit now, (b) what Earth's motion would be if that force vanished, and (c) why Earth's orbit is not a straight line even though Earth is always moving forward.
A comet travels in a long, oval orbit around the Sun. It moves very fast when it passes close to the Sun and very slowly when it is far away, near the orbit of Neptune.…
A comet travels in a long, oval orbit around the Sun. It moves very fast when it passes close to the Sun and very slowly when it is far away, near the orbit of Neptune. (a) Explain this change in speed using gravity. (b) Describe where the comet's tail points when it is near the Sun and why a tail forms only there. (c) Explain why astronomers think some comets come from the Kuiper belt or the Oort cloud.