This January 31st, the Moon will be located on the opposite side of the Earth as the Sun and its face will be will be fully illuminated. Since this is the second full moon in the same month, it is sometimes referred to as a blue moon. This is also the last of two supermoons for 2018. The Moon will be at its closest approach to the Earth and may look slightly larger and brighter than usual.
Irene W. Pennington Planetarium 