... Tomorrow , a full moon will occur that appears slightly larger and brighter than usual. ... Although the precise conditions that define a supermoon vary, given one definition, tomorrow's will be the third supermoon of the year -- and the third consecutive month that a supermoon occurs. ... Pictured above , a supermoon from 2012 is compared to a micromoon -- when a full Moon occurs near the furthest part of the Moon's orbit -- so that it appears smaller and dimmer than usual. ...