On Sunday night, June 14, the full moon will turn into something like an enormous grin.
A partial eclipse of the moon, visible throughout Utah, will darken the upper part of our companion orb. Earth's shadow will cover nearly 69 percent of the surface, leaving the lower 31 percent a bright crescent - like a wide smile.The first part of the penumbra, the dim outer portion of Earth's shadow, will sweep onto the moon's surface at 8:09 p.m. (MDT). But you won't see that: It will happen before the moon rises for this area, and some observers can't tell when the penumbra begins its move even when the moon is up.
At 9:27 p.m., the umbral phase will begin. For most, the entrance of the umbra - the dense part of the shadow - is the real beginning of the lunar eclipse show.
"Unfortunately, for most observers in this part of the country the moon will not rise until a few minutes after the eclipse starts," said Hansen Planetarium's Patrick Wiggins.
The umbra should be easy to see once the moon does come up. According to Sky & Telescope Magazine, the first part of the moon to be covered will be the Oceanus Procellarum region, on the upper left.
Mid-eclipse - when most of the lunar landscape will be bathed in a dense shadow - will be at 10:57 p.m., and the moon will be high enough to offer a good view. The umbral phase will end at 12:27 a.m. Monday, with the penumbra leaving the stage around 1:05 a.m.
Astronomy Magazine says during this eclipse, Earth's shadow may be darker than usual. Sulfuric acid mist and fine volcanic ash from the Mount Pinatubo eruption last year still hangs in the atmosphere and may filter out more sunlight than usual.
According to "Observer's Handbook 1992," published by the Royal Astronomical Society of Canada and used by astronomers worldwide, at mid-eclipse the moon will seem to be at the zenith of the sky for observers in northern Chile. That means for North Americans, it'll be relatively low toward the south.
"To provide the best views of this fascinating event, the Salt Lake Astronomical Society and the Hansen Planetarium will provide several large astronomical telescopes for use by the public," Wiggins said.
"The scopes will be set up in the parking lot of the Family Center, which is located at 980 E. Fort Union Boulevard in Midvale." For more information, call the planetarium's Starline, 532-STAR.