Saturday, April 4, 2015

Eclipsed Once Again

lunar eclipse (c) John Ashley
Cloudy lunar eclipse at 6 a.m. over Divide Mountain

Eclipse illustration from
Our first full moon of spring - what the Blackfeet call, When the ice breaks up in the river moon - was also the shortest total lunar eclipse of the 21st century. The moon passed through Earth's full shadow (umbra) for just 2 minutes and 17 seconds, but it spent almost six hours in Earth's partial shadow (penumbra). Our next lunar eclipse falls on September 28th, and it will be the last in this series of four total lunar eclipses known as a tetrad. The next tetrad won't begin until 2032.

The Earth's shadow crossing the moon will only be visible from Montana 14 times during the next 10 years, so lunar eclipses are slightly more frequent than your birthday. And like birthday cake, I'll enjoy a slice every time I get the chance. That's why I drove 6+ hours overnight for a so-so chance at photographing the eclipse over Divide Mountain, in Glacier Park. At 3 a.m. the sky was clear and the wind calm, and a northern pygmy owl called from a nearby clump of leafless aspens. And as soon as the eclipse started at 4:16 a.m., of course, clouds rolled in.

Near the time when the moon was supposed to be fully shadowed and rosy red, at totality, the eclipse snuck a peek through broken clouds for 10-15 seconds. But it ducked back behind the thick, blue blanket just as soon as it saw that I was still watching and waiting. I captured a quick shot of the recluse, like some sort of lunar paparazzi, and that's what I have to show for 6+ hours of driving and missing yet another night of sleep.

But that's still better than the fate of French astronomer Guillaume le Gentil. He was away from home for eleven and a half years in an effort to record either of the two transits of Venus during the 1760's. But he was stuck at sea during the first transit, and a cloud formed just at the moment of the second transit. He finally made his way back home where he discovered that his family had him declared dead before plundering his estate. And that's when Gentil gave up astronomy.