GRE Reading Comprehension
Home > GRE Test > GRE Reading Comprehension Questions
Next steps
- Use your browser's back button to return to your test results.
- Do more GRE Reading Comprehension Questions.
Source: 2014
The binary planet hypothesis—that Earth and the Moon formed simultaneously by the accretion of smaller objects—does not explain why the Moon's iron core is so small relative to the Moon's total volume, compared with Earth's core relative to Earth's total volume. According to the giant-impact hypothesis, the Moon was created during a collision between Earth and a large object about the size of Mars. Computer simulations of this impact show that both of the objects would melt in the impact and the dense core of the impactor would fall as molten rock into the liquefied iron core of Earth. The ejected matter—mantle rock that had surrounded the cores of both objects—would be almost devoid of iron. This matter would become the Moon.
The giant-impact hypothesis as described in the passage answers all of the following questions EXCEPT:
- A What happened to the rock that surrounded the impactor's core after the impactor hit Earth?
- B What happened to the impactor's core after the impactor hit Earth?
- C Where did the impactor that collided with Earth originate?
- D Why is the Moon's iron core small relative to that of Earth?
- E What was the size of the impactor relative to that of Mars?