A special full moon will light up the weekend's night skies.
The full moon -- appearing at 4:32 a.m. Sunday -- peaks within 20 minutes of the moon's nearest encounter with Earth for all of 2013, making it the largest full moon of the year. Dubbed a "supermoon," it will appear 15 percent larger and 20 percent brighter than when it's at its farthest point -- and will not be so close again until August 2014.
It is part of an astronomical trifecta:
- The Earth, moon and sun are all in a line, creating a "full" moon.
- The moon's orbit brings it closest to Earth. At this perigee, it lies only 221,824 miles away.
- In two weeks, on July 7, the moon will swing out to the apogee -- its farthest point for the year -- 252,581 miles distant. That's because the moon orbits in an oval, rather than a circle.The tilt of the Earth's axis means the sun's rays hit us at the most direct angle, creating the longest day.