Moon orbits along an egg-shaped ellipse and its distance from us changes. Today, December 12^th, the moon is approaching its nearest point to Earth. So according to NASA, it should look about 14 percent bigger and 30 percent brighter than lesser full Moons we have seen earlier this year.

Moon takes about 28 days to orbit Earth, it reaches its point of closest approach, called perigee, about once a month. As the moon’s orbit is not a perfect oval, it wobbles — some perigees are closer than others. Today’s approach will be the closest the moon has come to Earth since 1993.  If you miss the moon tonight, next time you will whiteness similar event in 2016.

As moon will be closest to earth, tides should be big too. But there is no reason to worry as lunar gravity at perigee pulls tide waters only an inch or so.

Source: NASA.