Editorial

'Once in a Blue Moon' is Saturday

Friday, July 30, 2004

"Once in a Blue Moon" means something happens rarely, but Saturday is a rare day, indeed. But not as rare as some of us think.

The phrase goes back hundreds of years, perhaps in reference to rare atmospheric conditions caused by forest fires and volcanic eruptions that have actually given the moon a bluish appearance.

But according to experts, the modern application is actually a misinterpretation of an old Maine Farmers' Almanac.

According to a Sky & Telescope magazine article of 1999, in a 1946 issue of the magazine, James Hugh Pruett misinterpreted the almanac, and wrote that a blue moon is the second full moon in the month.

Originally, according to the almanac, a blue moon referred to the fourth full moon in one of the four seasons.

Pruett's answer, however, made it into a 1986 edition of the popular Trivial Pursuit board game, and the rest, as they say, is history.

According to Sky & Telescope, the average time between full moons is 29.5 days, so a blue moon in February would be rare indeed.

A month with 30 days must have its initial full moon on the first of the month, but months with 31 days can have two full moons if the first one occurs by the second day of the month.

The next blue moon won't occur until May 2007.

So if moonlight walks are special to you and your sweetheart, Saturday is your chance.


But if you'd rather see the stars, mark your calendars for Thursday, Aug. 12. After midnight that day, the Perseid meteor showers will return for their usual mid-August appearance.

The meteors are fragments of comet Swift-Tuttle, which orbits the Sun every 130 years or so. When it is close to the sun, it sheds countless particles of dust, which over time spread out around the comet's orbit. Each August, the Earth sweeps through the dust, creating fiery streaks as the particles disintegrates

Typically, about 60 meteors per hour will appear at the peak, according to Daniel Glomski, curator of astronomy at the J.M. McDonald Planetarium at the Hastings Museum.

While they come back every summer, weather and bright moonlight often interfere.

"It's been years since we've seen the Perseids well," Glomski said. "It seems like either moon phase or weather, or both ruin them for us."

The moon won't be a factor this year, so only the weather can keep skywatchers from enjoying the show.

For the best view, get away from city light, lie back in a reclining lawn chair, blanket or sleeping bag, and keep your eyes scanning the sky. Although the meteors appear to originate from the constellation Perseus, for which the shower is named, they can appear anywhere.

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