Question

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what causes the phases of the moon?
the changing angles of the earth, moon, and sun as the earth revolves around the sun.
the changing angles of the earth, moon, and sun as the moon rotates on its axis.
the changing angles of the earth, moon, and sun as the earth rotates on its axis.
the changing angles of the earth, moon, and sun as the moon revolves around earth.

Explanation:

To determine the cause of lunar phases, we analyze each option:

• Option 1: Earth revolving around the Sun doesn't directly cause lunar phases (lunar phases are about Moon - Earth - Sun alignment as Moon orbits Earth).
• Option 2: The Moon's rotation on its axis (which is synchronous, so we always see the same face) doesn't cause phase changes. Phase changes are due to orbital motion, not rotational motion of the Moon on its own axis.
• Option 3: Earth's rotation on its axis causes day - night, not lunar phases. Lunar phases are related to the Moon's position relative to Earth and Sun, not Earth's rotation.
• Option 4: As the Moon revolves around Earth, the relative positions of Earth, Moon, and Sun change. This change in angle affects how much of the Moon's sun - lit side is visible from Earth, which causes the lunar phases.

Answer:

D. The changing angles of the Earth, Moon, and Sun as the Moon revolves around Earth.