Listen to part of a lecture in an astronomy class.
Professor: Today we're going to talk about the asteroid belt, which lies between Mars and Jupiter. You might think that this region is crowded with rocks, but actually it's mostly empty space. The total mass of all the asteroids is less than that of our Moon. Now, why didn't these asteroids form into a planet? Well, the main reason is Jupiter's gravity. Jupiter's strong gravitational pull, especially during the early solar system, stirred up the orbits of the planetesimals in that region, preventing them from colliding and sticking together to form a larger body. Instead, they kept crashing into each other at high speeds, which often caused them to break apart rather than merge. So, the asteroid belt is a remnant of the solar system's formation, a kind of cosmic debris that never got the chance to become a planet.
❓ 题目 According to the professor, what is the primary reason the asteroids did not form into a planet?
A. The asteroid belt was too far from the Sun to accumulate enough material.
B. Jupiter's gravity disrupted the asteroid orbits, preventing them from merging.
C. The asteroids collided too gently to stick together.
D. The total mass of the asteroids was too great for gravitational attraction.
✅ 正确答案
Jupiter's gravity disrupted the asteroid orbits, preventing them from merging.
