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LUNAR ECLIPSE: If you live in North America, you're out of luck. Sky watchers on every other continent, however, will experience a total lunar eclipse on June 15th. The Moon will spend 100 minutes fully engulfed in Earth's shadow, making this the longest lunar eclipse in nearly 11 years. Maximum eclipse occurs on Wednesday night at 20:12 UT. [details] [animation]
SOLAR ACTIVITY: The chance of strong solar flares today is low, but the chance of giant prominences is 100%. Mike Borman photographed this one from his backyard observatory in Evansville, Indiana:
"A number of giant prominences are dancing around the limb of the sun," he reports. "They have beautifully intricate shapes."
Prominences are tendrils of hot plasma held aloft by solar magnetic fields. Today's are big enough to see with ease using no more than backyard solar telescopes. Where should you point your optics? Targets of interest may be found in a full-disk photo taken by Borman.
more images: from John Stetson of Falmouth, Maine; from Pete Lawrence of Selsey, West Sussex, UK; from Peter Desypris of Syros,Greece; from Jim Lafferty of Redlands, California
DROOPY DISH: Drivers traveling down Highway 395 in California's Eastern Sierra are accustomed to seeing a large white dish looming in front of the sandy-brown mountains. It's the 40-meter antenna at Caltech's Owens Valley Radio Observatory. On June 6th local resident Andrew Kirk was passing by the observatory when an extraordinary sight made him stop for a closer look. The antenna was apparently drooping and melting into the ground like a Dali watch:
"I realized I had seen a mirage image of the big dish," says Kirk, "so I went back to document it. Sadly, I had only a pocket camera with limited zoom. I improvised, though, and photographed the 'drooping dish' through one barrel of my binoculars. Amazingly, as I watched, the dish began to tilt upwards and within a few minutes it was pointing straight up. Had I passed a bit later I would have missed it."
According to atmospheric optics expert Les Cowley, the phenomenon was caused by "an abnormally warm air layer close to the ground that had a non-linear temperature gradient. The conditions were akin to stages of an Etruscan vase sunset mirage or the inferior mirages seen over sun-heated roads. Strictly speaking, however, this one was a distortion rather than a mirage because the latter is technically reserved for when there is more than one image of the distant object." A full discussion of the drooping dish may be found at Cowley's excellent Optics Picture of the Day website.
Kirk drives by the dish frequently and he's looking forward to a whole summer of warm air and temperature gradients. "I hope to see this again...with my better camera in tow."
June 2011 Aurora Gallery
[Aurora alerts: text, voice] [previous Junes: 2010, 2008, 2001]
Midnight Solar Eclipse Gallery
[NASA: A Rare Eclipse of the Midnight Sun]