Supermoon! Tonight's full moon is a lunar perigee which occurs when the moon, travelling in its elliptical orbit, reaches its closest point to our earth. As a consequence, the moon will appear about 15% larger and up to 30% brighter than usual. The best time to check it out is at sunset, when the moon is closest to the horizon.
The Supermoon will cause higher and lower tides than usual, but don't buy into all the malarkey that it will cause natural disasters (or has already caused the earthquake and tsunami in Japan).
Just enjoy this full moon's additional size and beauty!