An image from Supermoon Eve. The real Supermoon – technically known as a perigee moon – arrives tomorrow, at 11:32UTC. This will be the closest the moon is to earth in 2013. It won’t be this close again until August 2014. What’s so super about this moon? It should appear 14% larger, and about 30% brighter than a “normal” full moon. You may only find this exciting if you’re a giant science dork. If you do, we have at least one thing in common.