In a lunar eclipse, the Earth's shadow — called the umbra — blocks the sun's light from hitting the full moon, resulting in a dimmer moon with a distinct red and orange cast. It's also called a blood moon.

March's full "Blood Worm Moon," a phenomenon that makes the moon appear red during a total lunar eclipse, is visible this week for Americans and others in Earth's Western Hemisphere.The full moon reaches peak illumination at 2:55 a.