The largest full moon of 2013, a so-called "supermoon" will light up the night sky this weekend.  On June 23, the moon will be at perigee, the point in its orbit that is the closest to earth.  

Perigee happens once or sometimes twice each month, but this Sunday's is different.   Shortly after the perigee point, the moon turns full.   The combination will bring about the biggest full moon of the year.

During Sunday's "supermoon",  the moon will appear about 12.2 percent larger than it will look next January, when it will be at the farthest point from earth.  You can watch a free webcast on space.com on Sunday a 9 p.m.

Digital Journal