December 17, 2010

As you scan your eye around Earth's circumference, you're seeing every sunrise and every sunset in the world, all of them, all at once.

Monday night, the moon disappears and turns red for a big chunk of the Northern hemisphere: Solstice Lunar Eclipse  
This is the first time a total eclipse has happened on the Solstice in about 700 years.  It will be visible in all of North America (weather permitting) (ah overcast Idaho...), and partially, in Atlantic Northern Europe.  At the link you will find maps for that.  Quoth NASA: 

The eclipse begins on Tuesday morning, Dec. 21st, at 1:33 am EST (Monday, Dec. 20th, at 10:33 pm PST). At that time, Earth's shadow will appear as a dark-red bite at the edge of the lunar disk. It takes about an hour for the "bite" to expand and swallow the entire Moon. Totality commences at 02:41 am EST (11:41 pm PST) and lasts for 72 minutes.
If you're planning to dash out for only one quick look -­ it is December, after all -­ choose this moment: 03:17 am EST (17 minutes past midnight PST). That's when the Moon will be in deepest shadow, displaying the most fantastic shades of coppery red.

Why red?

A quick trip to the Moon provides the answer: Imagine yourself standing on a dusty lunar plain looking up at the sky. Overhead hangs Earth, nightside down, completely hiding the sun behind it. The eclipse is underway. You might expect Earth seen in this way to be utterly dark, but it's not. The rim of the planet is on fire! As you scan your eye around Earth's circumference, you're seeing every sunrise and every sunset in the world, all of them, all at once. This incredible light beams into the heart of Earth's shadow, filling it with a coppery glow and transforming the Moon into a great red orb.

2 comments:

Laurie Brown said...

Why *does* it have to be cloudy all winter here?!?! All the eclipses, all the auroras...

Of course, when it *is* clear out in winter, it's so cold all the stuff in your nose freezes up the second you step outside, so I guess it doesn't make much difference...

Judith said...

LOL! Yep. Idaho's sense of humor. I bundled up like a madwoman, and darted out, waiting for it to start, and then back in...out..in. It was visible in bites, but at totality, just the maroon darkness everywhere... rather neat.