- A supermoon is larger and brighter than an average full moon
- It happens when the moon is full and at its closest point to Earth
- One took place Saturday, and others will happen August 10 and September 9
What's better than a "supermoon"? Three supermoons!
The full moons of this summer -- July 12, August 10 and September 9 -- are supermoons, as NASA calls them.
The phenomenon happens when the moon becomes full on the same day as its perigee -- the point in the moon's orbit when it's closest to Earth.
"Generally speaking, full Moons occur near perigee every 13 months and 18 days, so it's not all that unusual," Geoff Chester of the U.S. Naval Observatory said in a statement from NASA. "In fact, just last year there were three perigee Moons in a row, but only one was widely reported."
Chester was talking about the supermoon that happened in June last year. It was 14% bigger and 30% brighter than other full moons of 2013, and garnered international headlines.
The moon-loving public from around the world got into the act and posted numerous photos of this weekend's supermoon on Twitter.
"Loving this super moon on the coast of NC tonight." one woman tweeted. "Super moon looks incredible right now!!!" a man tweeted.
NASA stressed 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.
"There's a part of me that wishes that this 'super-Moon' moniker would just dry up and blow away, like the 'Blood-Moon' that accompanied the most recent lunar eclipse, because it tends to promulgate a lot of mis-information," Chester said in his statement.
"However, if it gets people out and looking at the night sky and maybe hooks them into astronomy, then it's a good thing."