Tonight's total lunar eclipse also holds special significance, since this is the first time since 1554 that it coincides with the winter solstice.
Tonight, our local satellite, the moon, will experience a full lunar eclipse. It begins at 1:33 a.m. Eastern, followed by the onset of totality at 2:41 a.m., and the good folks at NASA say the best moment for viewing is 3:17 a.m. The eclipse will be visible across all North America.
Now, a lunar eclipse doesn't look like a solar eclipse. Don't expect a sharply defined perfect circle to completely blot out the face of the moon. Instead, when the Earth cuts in front of the path between the sun and the Moon, the moon takes on variety of red tones. Here's how NASA explains the rouging:
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.
If you take any great photos of the eclipse, though, we want to see them. This concludes your Atlantic Technology Channel PSA.
During a total lunar eclipse, the moon has been known to turn dazzling colors: blood red, deep copper orange, and sometimes dark grey or brown.
For those of you tough enough to get out of your warm beds and into the winter solstice weather to turn your attention skyward, Tuesday morning's early hours mark the first total eclipse of the moon in two years. During this time, the moon will pass behind the earth, slip into the earth's shadow, become engulfed by that shadow, and then reemerge.
And if you happen to be in North America, Ireland or Greenland, you're perfectly positioned to see the moon pass through the northern part of the earth's shadow - weather and cloud-cover allowing, that is.
Here's how it works: The earth's shadow is cone-shaped and divided into two portions: the dark, inner umbra is nested inside the pale, outer penumbra. As the moon moves into the center of the umbra, it aligns with the sun and earth. There, hidden behind the earth, the moon is blocked from the sun's rays.
But a thin ring of atmosphere around the edge of the earth gets lit up by sunlight and refracted back onto the moon's surface. That's what causes the copper orange or red colors seen during an eclipse, says Jim O'Leary, senior director of the Maryland Science Center.
"We're never really sure what it's going to look like," he says. "It's really a function of whatever is going on in the atmosphere." Dust from volcanic eruptions, for example, can thicken the air and darken the color of an eclipse by canceling some of the light that gets reflected back onto the moon.
The eclipse will last three hours and 28 minutes. For 72 of those minutes, the earth's shadow will completely cover the moon, according to NASA.
Plus NASA plans to stream live video of the event and have astronomers available to answer questions online.
The moon will begin to enter the umbra at 1:32 am EST, at which point a visible dark shadow will start creeping across the moon's face. The total eclipse begins at 2:40 am, when the moon's final edge slips into the umbra. It will stay in the shadow until 3:53 am, and should be completed by 5:02 am. Meteorologist and astronomy writer Joe Rao details the 12 stages of the total lunar eclipse in this Space.com article.
The prime time to see the eclipse is 3:17 am EST, O'Leary says. "That's when the moon will be in deepest part of the shadow."
