Which alignment causes a solar eclipse?

• A. The Moon passes between the Sun and the Earth
• B. The Earth passes between the Sun and the Moon
• C. The Moon passes behind the Sun
• D. The Sun passes between the Moon and the Earth

Answer: (A)

A solar eclipse happens when the Moon sits directly between the Sun and the Earth, so the Moon blocks the Sun’s light from reaching parts of the Earth. That straight-line alignment is what creates the shadow on Earth and makes the Sun appear briefly obscured.

If the Earth were between the Sun and the Moon, the Earth would cast its shadow onto the Moon, producing a lunar eclipse, not a solar one. If the Moon were behind the Sun, or if the Sun were between the Moon and the Earth, the Sun’s light wouldn’t be blocked from Earth, so no solar eclipse occurs.