Happy Friday the 13th! Not only is it the 13th, but today brings an extra twist. A "harvest" moon (full moon) will be visible in the sky tonight. It is rare for a full moon to appear on Friday the 13th. The last time this happened was on Oct. 13, 2000. According to the Farmers Almanac, the next Friday the 13th with a full moon will occur on Aug. 13, 2049. So enjoy!