NASA says this summer's full moons will all be "supermoons."
The first will be visible Friday and Saturday night.
The scientific term for the phenomenon is "perigee moon." It makes the moon appear larger and brighter.
It will happen again August 10 and September 9. Experts say the one on August 10 will likely be the brightest.
Although scientists stress that sometimes it's hard to tell the difference between a supermoon and a regular full moon, as clouds and haze can mask a difference in brightness.