LATE TONIGHT: If the clouds stay away, Alaskans can see the whole beautiful event with the naked eye.
Worknight or no, Christopher Erickson will be outside his South Anchorage home at 2:37 a.m. Tuesday looking up at one of nature's fleeting but predictable beauties.
If the clouds cooperate early Tuesday, Alaskans will get a view of a full moon shifting from white to dark orange or even blood red. People throughout most of the Americas have a chance to view a total lunar eclipse then.
It's not a rare occurrence, as compared with visits by comets. The moon passes completely into Earth's shadow at least twice and sometimes thrice a year, each visible from half the world. But it's one of the most beautiful sights in the night sky, and it's visible to the naked eye, Erickson said.
"I wouldn't miss it, but I'm pretty hard core," Erickson said.
Erickson is a computer network engineer who coordinates an amateur astronomy club and online forum for the Anchorage area. He said the Glenn Highway is a likely place for many enthusiasts to escape the city lights for a good view.
"That would be a great place for a front-row seat to the action," he said.
He figures he should get a clear enough view from South Anchorage, though, with the moon rising to 17.5 degrees above the southern horizon.
At the University of Alaska Anchorage, physics and astronomy professor Don Martins said the sky will be impressive. Still, as the semester begins, he won't send students out for late-night homework.
"Lunar eclipses are not particularly useful events scientifically, but they're very pretty," he said.
What he means is that these eclipses don't help unveil secrets of the universe the way solar eclipses might. During solar eclipses, astronomers can measure the relative locations of stars and measure the distortion of light, helping test Einstein's theory of relativity, he said.
During a lunar eclipse, it just a matter of appreciating the eerie beauty.
The moon becomes slightly faint as it moves into Earth's penumbra, the outer cone of shadow in which light is refracting. Then it enters the umbra, or inner shadow, where the only light it receives is that which skitters through Earth's atmosphere. The result of this process, similar to what happens when rays from a sunset bounce through more atmosphere particles before reaching Earth, is a reddening, Martins said.
It's pretty, but Martins has seen it over and over.
"I've been around so long that these events no longer pique my interest because they happen so often," he said.
4 1/2- HOUR EVENT
For Erickson and other Alaska amateurs, though, they're a treat. Coastal Alaska, tucked between sea and mountains, naturally gathers more clouds than much of the United States, he said. He has seen maybe 20 lunar eclipses in his life, but only two during a decade in Alaska.
The last total eclipse was March 3, but in Alaska it was visible only in the Arctic.
Tuesday's eclipse begins at 12:20 a.m. and enters the total phase -- inside the umbra -- at 1:52 a.m., Martins said.
Mid-eclipse is 2:37 a.m., and the total eclipse phase lasts another 45 minutes. The whole show ends at 4:55 a.m.
Martins recommends using either binoculars or the naked eye. Most telescopes magnify the moon too much for a total picture.
Find Brandon Loomis online at adn.com/contact/bloomis or call him in Soldotna at 1-907-260-5215, ext 24.
