Stargazing San Antonians will on Tuesday be able to admire the second supermoon of the year, named so because it appears bigger and brighter in the sky due to its proximity to Earth, news station KXAN reports. NASA defines a supermoon as “any full moon occurring around the same time as the moon’s perigee, or closest point of orbit with the Earth.” Today’s supermoon will reach full illumination Tuesday afternoon, hitting its peak at 3:32 p.m.