The second full moon of July rose Friday night, a phenomenon referred to as a “blue moon.”
Though the phrase “once in a blue moon” is meant to describe a rare event, a blue moon is neither rare, or blue. “Blue moon” is actually a term used to describe the second full moon in a single calendar month. Most years only have 12 moons, but this year has 13, which happens every two to three years, according to astronomers. “Blue moons” don’t actually appear blue, but the moon can appear blue after events on earth like wildfires and volcanic eruptions, according to NASA.
PHOTOS: 20 Breathtaking Images of Earth From Space
Aleppo, Syria, May 26, 2013 – The Citadel of Aleppo – medieval fortified palaceDigitalGlobe—Getty ImagesBelfast, Northern Ireland, Nov. 3, 2013 – “Wish,” a large-scale art workDigitalGlobe—Getty ImagesUtah, USA, April 22, 2013 – Colorado RiverDigitalGlobe—Getty ImagesCuanza River, Angola, April 28, 2013 – Cambambe DamDigitalGlobe—Getty ImagesDoha, Qatar, March 4, 2013 – Artificial island spanning nearly four million sq meters.DigitalGlobe—Getty ImagesDunalley, Australia, Jan. 6, 2013 – fires, false color image (red = healthy vegetation)DigitalGlobe—Getty ImagesAustralia, April 22, 2013 – Great Barrier ReefDigitalGlobe—Getty ImagesGwadar coast, Pakistan Sept. 29, 2013 – new island created by earthquake in PakistanDigitalGlobe—Getty ImagesCroatia, Feb. 16, 2013 – Galešnjak (Island of Love)DigitalGlobe—Getty ImagesHong Kong, China May 9, 2013 – giant rubber duckDigitalGlobe—Getty ImagesMadang Province, Papua New Guinea, March 22, 2013 – Manam VolcanoDigitalGlobe—Getty ImagesNamib Desert, Namibia, May 13, 2013 – Sossusvlie areaDigitalGlobe—Getty ImagesNaples, Italy, Feb. 19 2013 – Mount VesuviusDigitalGlobe—Getty ImagesNiger, Feb. 13, 2013 – Arlit Uranium MineDigitalGlobe—Getty ImagesSchooner Cays, Bahamas, May 26, 2013DigitalGlobe—Getty ImagesSochi, Russia, March 17, 2013 – Site of 2014 winter OlympicsDigitalGlobe—Getty ImagesNear the city of Sur, Oman, Feb. 13, 2013 – massive “green tide”DigitalGlobe—Getty ImagesValencia, Spain, July 19, 2013 – Palau de les Arts Reina Sofia and Gulliver Park with an enormous fiberglass model of Lemuel Gulliver trappedDigitalGlobe—Getty ImagesVersailles, France, Aug. 20, 2013 – Palace of VersaillesDigitalGlobe—Getty ImagesXi'an, China, Sept. 24, 2013 – Shiyuan Park DigitalGlobe—Getty Images
