Monday, February 18, 2008

Lunar eclipse may be visible on Wednesday


Astronomers are hoping for clear skies on Wednesday when the moon passes completely into the Earth’s shadow, offering the last chance for a look at a total lunar eclipse in the next few years.
Members of the Santa Barbara Astronomical Unit, a local astronomy club, will set up telescopes at Shoreline Park and implore the skies to remain cloud-free from about sunset to 8 p.m.

Forecasts call for a 30 percent chance of rain Wednesday morning followed by partly sunny skies throughout the day, according to the National Weather Service. But Wednesday night is expected to be mostly cloudy.
“We’re always at the mercy of the weather and you can’t trust any predictions, so we just sort of go with the flow,” said Chuck McPartlin, outreach coordinator for SBAU.
The moon will rise in the east already partially eclipsed at around 6 p.m. and will enter totality, the astronomical term for complete immersion within the Earth’s inner shadow, at 7 p.m. The total eclipse will last about 50 minutes, according to predictions by astrophysicist and eclipse expert Fred Espenak, of NASA’s Goddard Space Flight Center.
During total lunar eclipses, the moon takes on a colorful appearance. Bright orange, blood red and dark brown are common, according to Espenak’s website, while dark gray is a rare occurrence.
“Dark eclipses are caused by volcanic gas and dust, which filters and blocks much of the sun’s light from reaching the moon,” Espenak wrote. “But since no major volcanic eruptions have taken place recently, the moon will probably take on a vivid red or orange color during the total phase.”
Lunar eclipses are safe to watch without protective filters, unlike solar eclipses. Although they are visible with the naked eye, Espenak suggests using a pair of binoculars to enhance the view and make the coloration brighter.
“Although total eclipses of the moon are of limited scientific value, they are remarkably beautiful events which do not require expensive equipment,” he wrote.
The last total lunar eclipse visible from the United States took place on August 28, 2007, and lasted approximately 90 minutes. That event started at around 3 a.m., McPartlin said, not a very convenient time for casual observers of the night sky.
He hopes the timing of tomorrow’s eclipse will bring the public out to Shoreline Park or other viewing areas.
“It’s just a good excuse to get people out and interested in astronomy,” he said.
And while there is always the possibility that cloudy skies will thwart attempts to view the lunar phenomenon, the next opportunity to see a full eclipse of the moon won’t be until late 2010.

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