After this summer's three consecutive supermoons -- more appropriately called perigee full moons – it's difficult to imagine what our planet's natural satellite might do to turn even more Earthly eyes to the sky.
The moon will make its next appearance on the cosmological center stage Wednesday morning just before sunrise during a total lunar eclipse visible from the Pittsburgh area, weather permitting. A lunar eclipse occurs when the moon enters Earth's shadow, keeping sunlight from illuminating it fully.
Then, in about two weeks, the moon will seem to take a bite from the sun during a partial solar eclipse that will occur Oct. 23 not long before sunset. A solar eclipse occurs when the moon passes in front of the sun as seen from Earth.
With so much lunar activity over a few months, some may wonder if it's a harbinger or omen of sorts. Not so, said Brendan Mullan, director of Buhl Planetarium & Observatory at Carnegie Science Center.
“There's nothing mystical about it,” Mr. Mullan said. “These events are predictable. They can just bunch up from time to time ... every once in a while, you get lucky.”
A perigee full moon, or supermoon, occurs when the moon is full and, in its elliptical orbit about our world, comes within 90 percent of its closest approach. Wednesday’s full moon will not meet that definition – the moon at about 6 a.m. Monday was at its closest – but it is special nonetheless. In October, it's best known as the Hunter's Moon, named by Native Americans who at this time of year were on a hunt to store meat for the upcoming winter.
Early risers Wednesday may start to notice something odd about the moon after 4:30 a.m. By then, it will have started to move into Earth's penumbra, the light outer portion of our planet's shadow that will cause a slight shading.
The first bite of moon occurs when it enters the dark umbra just before 5:15 a.m. The total eclipse begins at 6:25 a.m. By then, the sky is getting bright from the sun, which rises about 7:24 a.m., the moment of greatest lunar eclipse. For Pittsburghers, the moon sets just four minutes later, so the final stages of the eclipse will not be visible.
Despite the interference of the morning twilight and the moon's proximity to the western horizon, the eclipse still should be an entertaining event.
“The Earth casts a pretty large shadow, so you're going to see it pretty much wherever you are,” said Mr. Mullan, who holds a doctorate in astronomy from Penn State. “As long as conditions are right ... as long as it's nice out, not too humid, not too cloudy ... you'll be able to see it.”
Eric Fischer of Hampton, a longtime member of the Amateur Astronomers Association of Pittsburgh and veteran lunar observer, said the moon won't disappear entirely during the eclipse. “Sometimes it's a little lighter red color, sometimes it's a real dark blood-red color, but you can always see the full disk of the moon.”
The eclipse can be “a little creepy in some regards,” Mr. Mullan said with a laugh. “You see the Earth's shadow start to gobble up more and more of the moon. And as it passes into totality, the moon actually turns red.” The color is caused by sunlight passing through and being scattered by Earth's atmosphere.
Even before totality, there's something just as interesting that becomes apparent.
“The neat thing about the lunar eclipse is that it proves that the Earth is round,” Mr. Fischer said. “The shadow the Earth projects on the moon” is curved, and “that's proof positive we live on a round planet.”
The Oct. 23 solar eclipse occurs when the sun is very low in the west, so it will be a relatively brief and less dramatic event. The partial eclipse begins at 5:46 p.m. Local sunset is at 6:27 p.m.
Despite its low altitude, the solar glare is harmful to human eyes.
“Do not look anywhere near the sun unless you have at a minimum a No. 14 welder's glass” or a proper Mylar filter, Mr. Fischer said. “Even if the moon covers 80 percent of the sun, there's enough there to blind you. And that happens to people.
“If you can't get the welder's glass, project an image of the sun with a pinhole. Use a piece of cardboard against a piece of white paper. You'll see a ’bite’ taken out of the sun,” he said.
Local skywatchers are hopeful Wednesday’s eclipse of the moon won't meet the same fate as the April 15 event. After several days of beautiful spring weather, a cold front moved through, bringing clouds that blotted out the eclipse.
Pittsburgh will experience two total lunar eclipses in 2015. The moon will set during the April 4 eclipse; the entire eclipse Sept. 28 will be visible. The next solar eclipse is a deep partial event visible from Pittsburgh on Aug. 21, 2017 – part of an event millions will witness as a total eclipse of the sun from Oregon and Idaho through the central U.S. and into South Carolina.
First Published: October 7, 2014, 4:00 a.m.
