This weekend, Californians took advantage of unseasonably warm weather and clear skies to admire the “supermoon,” also known as a perigee moon, which occurs when the moon is unusually close to the earth.
CBS13 in Sacramento, reporting on Saturday’s full-moon event, quoted Vice President Walt Heiges of the Sacramento Valley Astronomical Society saying, “The supermoon appears because the moon is closer to the earth than it normally is during its orbit…When they see it in the horizon, there’s an optical illusion there, and that optical illusion causes the moon to look a lot bigger.”
He added, “You want to get high, up in the mountains somewhere, and then that way, you get above the sky glow and you get to see what’s really going on.”
The next two occurrences of the supermoon are expected to fall on August 10 and September 9.
Geoff Chester of the U.S. Naval Observatory said, “Generally speaking, full Moons occur near perigee every 13 months and 18 days, so it’s not all that unusual. In fact, just last year there were three perigee Moons in a row, but only one was widely reported.” Chester was referring to the supermoon from June 2013, which was 14% bigger and 30% brighter than the other full moons of 2013.
Photo: Supermoon in Lebanon. Jamal Saidi/Reuters