A total lunar eclipse occurs when the moon and the sun are on
exact opposite sides of Earth, according to NASA. When this
happens, Earth blocks sunlight that normally reaches the moon.
Instead of sunlight hitting the moon’s surface, Earth's shadow
falls on it.
Starting at 9:36 p.m.
EST Jan. 20, sky-watchers will notice a "little notch is taken
out of the moon," according to Brian Murphy, director of
Indiana's Holcomb Observatory & Planetarium and Butler
University professor. "The moon starts to enter into the earth's
shadow in a portion called the umbra when the sun is totally
blocked out," he said. "Earth is moving from right to left
through the shadow."
At 10:34 p.m., it moves
into a partial eclipse, and starting at 11:41 p.m., the full
eclipse begins; a maximum eclipse occurs at 12:12 a.m. Jan. 21.
The total eclipse ends at 12:44 a.m.