Final answer:
The false statement about Earth's Moon is that it is a captured asteroid. The Moon likely formed from debris from a giant impact with Earth, not from a captured asteroid, based on compositional similarities and its orbit.
Step-by-step explanation:
The statement about Earth's moon that is false is that it is a captured asteroid. The leading theory for the Moon's formation is the giant impact hypothesis, which suggests that the Moon was formed from the debris ejected when a Mars-sized body collided with Earth around 4.5 billion years ago. Moreover, the compositional similarities between the Earth and the Moon, such as an identical fraction of major oxygen isotopes, argue against the capture theory. This theory, which posits that the Moon was captured by Earth's gravity, is the least plausible due to the difficulty of such a capture resulting in the Moon's nearly circular orbit and the lack of a mechanism for a substantial loss of energy needed for capture.