Multiple choice A solar eclipse occurs when? a dragon swallows the Sun the moon casts a shadow on the Earth the earth casts a shadow on the moon the Sun is blocked by an asteroid Reveal answer Fill a bubble to check yourself B Correct answer Explanation A solar eclipse occurs when the Moon passes directly between the Sun and the Earth, blocking the Sun's light and casting a shadow on a portion of the Earth's surface. A lunar eclipse, by contrast, occurs when the Earth casts a shadow on the Moon.