Saturday's full moon will be a super "perigee moon" -- the biggest in almost 20 years. This celestial event is far rarer than the famed blue moon, which happens once about every two-and-a-half years. . .
"Nearby perigee moons are about 14% bigger and 30% brighter than lesser moons that occur on the apogee side of the moon's orbit," the NASA website says.
This full moon will rise in the east at sunset and should look especially big at that time because of what's known as the "moon illusion."
Jim Berkland predicts "the big one" on the west coast, probably California near the bay area, between March 19th and the 26th.