The moon goes through several phases, as you undoubtedly learned -- and forgot -- in elementary school. This photograph, taken by Ralph H. Bernstein on April 14, 2011, from Monmouth County, New Jersey, shows our only natural satellite in a waxing gibbous state with 83 percent illuminated.
"A gibbous moon is but one of the moon's phases and occurs when the size of the illuminated portion is greater than half, but not yet a full moon," NASA explained. "A waxing gibbous moon is the period between a first quarter moon and a full moon, when the illuminated region of the moon is increasing each day."
View more Pictures of the Day.
We want to hear what you think about this article. Submit a letter to the editor or write to email@example.com.