Which Moon formation hypothesis describes a collision between Earth and a large asteroid that released crustal material into orbit, from which the Moon accreted?

Which Moon formation hypothesis describes a collision between Earth and a large asteroid that released crustal material into orbit, from which the Moon accreted?

• A. The Fission model
• B. The Capture model
• C. The Double-Impact model
• D. The Giant-Impact hypothesis

Answer: (D)

A giant-impact event is the best description here. The idea is that a large body collided with early Earth, blowing a disk of crust and mantle material into orbit. That orbiting debris gradually clumped together to form the Moon. This scenario matches the given description of crust being ejected into orbit and the Moon accreting from that material. It also lines up with evidence like the Moon’s geochemical similarity to Earth's mantle and the system’s angular momentum. Other models don’t fit as well: fission relies on Earth spinning extremely fast to fling material outward, capture requires the Moon to form elsewhere and be captured by Earth, and a double-impact variant involves two collisions rather than a single event. The single, large-impact picture best fits the described process.

A giant-impact event is the best description here. The idea is that a large body collided with early Earth, blowing a disk of crust and mantle material into orbit. That orbiting debris gradually clumped together to form the Moon. This scenario matches the given description of crust being ejected into orbit and the Moon accreting from that material. It also lines up with evidence like the Moon’s geochemical similarity to Earth's mantle and the system’s angular momentum. Other models don’t fit as well: fission relies on Earth spinning extremely fast to fling material outward, capture requires the Moon to form elsewhere and be captured by Earth, and a double-impact variant involves two collisions rather than a single event. The single, large-impact picture best fits the described process.