What is the MOST probable heat source that produced extensive, maybe even total, melting of the Moon at an early stage in its history?
A) nuclear fusion reactions occurring in its core
B) intense sunlight from the early and very active Sun
C) tidal flexing and distortion caused by its motion around Earth
D) the impact energy of meteoritic bombardment

Question

Quizplus · Accepted Answer

The most probable heat source that produced extensive, maybe even total, melting of the Moon at an early stage in its history is the impact energy of meteoritic bombardment. This process, known as the "giant impact hypothesis," suggests that the heat generated from numerous meteorite impacts would have been sufficient to melt a significant portion of the Moon's surface, leading to the formation of its early magma ocean.

What Is the MOST Probable Heat Source That Produced Extensive