During the eclipse, the full moon will pass through the Earth's shadow. It appears red, known as a "blood moon," as light is scattered through the Earth's atmosphere, much like during a sunset.
In addition, the moon will be at perigee, or the closest point to Earth in its orbit, making it appear about 7% larger than normal and 15% brighter or a "super moon," according to astronomers. May's full moon is known as the "Flower Moon" since it occurs when spring flowers are in bloom.
The result when taken together is a "Super Flower Blood Moon."