This weekend’s full moon sparked curiosity and plenty of social media speculation. The “supermoon,” as it’s dubbed, appeared as a larger full moon, pleasing amateur astronomers and photographers alike.

Though there are plenty of photos of the moon to be found on the internet today, a clear explanation for why the moon appeared as it did is rather harder to come by. Though many unfounded rumors and theories have been put forward, NASA can alway be counted on to state things plainly.

The agency has put out a new video succinctly explaining the supermoon phenomenon. Michelle Thaller, the assistant director for science communication at NASA’s Goddard Space Flight Center, explains that a supermoon is when a full moon occurs near the moon’s perigee – the point at which the moon is closest to Earth in its orbit. That’s it. Nothing too apocalyptic or prophetic. In fact, a supermoon, Thaller says, is only around 12% larger than a normal full moon.

(Image courtesy NASA/Bill Ingalls)