For all of those that love to watch the night sky. Tonight will bring a rare treat. A Total Lunar Eclipse will occur and pending cloud cover, a good portion of the those in the United States will have a great view. Lunar eclipses occur when Earth’s shadow blocks the sun’s light, which otherwise reflects off the moon. There are three types — total, partial and penumbral — with the most dramatic being a total lunar eclipse, in which Earth’s shadow completely covers the moon.
Image from Wikipedia
Observers from the Atlantic coast across the Americas to the far side of the Pacific Ocean will be able to observe a total lunar eclipse on Monday night, 14-15 April 2014.
The eclipse begins at 12:53 a.m. EDT (9:53 p.m. PDT).
Exact event times for your city can be calculated at http://aa.usno.navy.mil/data/docs/LunarEclipse.html.
| Approximate time for Zone: | Eastern | Central | Mountain | Pacific | Alaska Mainland | HI-Aleutians |
| Penumbral Eclipse Begins: | 00:53:37 | 23:53:37 | 22:53:37 | 21:53:37 | Below horizon | 18:53:37 |
| Partial Eclipse Begins: | 01:58:19 | 00:58:19 | 23:58:19 | 22:58:19 | 21:58:19 | 19:58:19 |
| Total Eclipse Begins: | 03:06:47 | 02:06:47 | 01:06:47 | 00:06:47 | 23:06:47 | 21:06:47 |
| Greatest Eclipse: | 03:45:40 | 02:45:40 | 01:45:40 | 00:45:40 | 23:45:40 | 21:45:40 |
| Total Eclipse Ends: | 04:24:35 | 03:24:35 | 02:24:35 | 01:24:35 | 00:24:35 | 22:24:35 |
| Partial Eclipse Ends: | 05:33:04 | 04:33:04 | 03:33:04 | 02:33:04 | 01:33:04 | 23:33:04 |
| Penumbral Eclipse Ends: | 06:37:37 | 05:37:37 | 04:37:37 | 03:37:37 | 02:37:37 | 00:37:37 |
During the eclipse the moon will pass through Earth’s shadow. An outer zone, called the penumbra, is only “lightly” shadowing the moon. You can’t see that portion, called the penumbral eclipse, except for a few minutes before the partial eclipse begins and a few minutes after the partial eclipse ends.
The main show begins with the partial eclipse. During the partial eclipse more and more of the moon enters (and later exits) the deep shadow cast by the Earth, called the umbra. The disk of the moon in the umbra gets very dark while the portion outside the umbra stays quite bright.
The total eclipse begins when the whole disk of the moon is inside the umbra and lasts for 1 hour 18 minutes. During this period the moon can have a range of colors, spanning deep grey (or invisible, sometimes) to bright orange.
This is an event for the naked eye and binoculars if desired. Wear clothing suitable for nighttime weather. A chair, lounge, or mattress and a blanket or sleeping bag will make observing more comfortable if you stay out for most of the event.
What’s Happening
Lunar eclipses occur when the moon passes through the shadow cast by Earth, cutting off the sunlight usually falling on the full moon. While full moons occur every 29.5 days, we do not see a lunar eclipse every month. Because the moon’s orbit is tilted with respect to the Earth’s orbit, the moon must pass close to the line projecting from sun to Earth so it will pass through Earth’s shadow. This close alignment occurs about every 6 months. If the moon is close enough to the line, a partial or total lunar eclipse can be seen from somewhere on Earth. Earth’s shadow is much larger than the moon. As it crosses through Earth’s shadow, the moon spends enough time that Earth’s rotation brings large areas of our planet into position to see the moon.
Image from Griffith Observatory
What is a lunar eclipse?
A lunar eclipse can occur only at full moon. A total lunar eclipse can happen only when the sun, Earth and moon are perfectly lined up — anything less than perfection creates a partial lunar eclipse or no eclipse at all. Some understanding of simple celestial mechanics explains how lunar eclipses work.
Because the moon’s orbit around Earth lies in a slightly different plane than Earth’s orbit around the sun, perfect alignment for an eclipse doesn’t occur at every full moon. A total lunar eclipse develops over time, typically a couple hours for the whole event. Here’s how it works: Earth casts two shadows that fall on the moon during a lunar eclipse: The umbra is a full, dark shadow. The penumbra is a partial outer shadow. The moon passes through these shadows in stages. The initial and final stages — when the moon is in the penumbral shadow — are not so noticeable, so the best part of an eclipse is during the middle of the event, when the moon is in the umbral shadow.
Total eclipses are a freak of cosmic happenstance. Ever since the moon formed, about 4.5 billion years ago, it has been inching away from our planet (by about 1.6 inches, or 4 centimeters per year). The setup right now is perfect: the moon is at the perfect distance for Earth’s shadow to cover the moon totally, but just barely. Billions of years from now, that won’t be the case.
Types of lunar eclipses
Total lunar eclipse: Earth’s full (umbral) shadow falls on the moon. The moon won’t completely disappear, but it will be cast in an eerie darkness that makes it easy
to miss if you were not looking for the eclipse. Some sunlight passing through Earth’s atmosphere is scattered and refracted, or bent, and refocused on the moon, giving it a dim glow even during totality. If you were standing on the moon, looking back at the sun, you’d see the black disk of Earth blocking the entire sun, but you’d also see a ring of reflected light glowing around the edges of Earth — that’s the light that falls on the moon during a total lunar eclipse.
Partial lunar eclipse: Some eclipses are only partial. But even a total lunar eclipse goes through a partial phase on either side of totality. During the partial phase, the sun, Earth and moon are not quite perfectly aligned, and Earth’s shadow appears to take a bite out of the moon.
Penumbral lunar eclipse: This is the least interesting type of eclipse, because the moon is in Earth’s faint outer (penumbral) shadow. Unless you’re a seasoned skywatcher, you likely won’t notice the effect.
The blood-red moon
The moon may turn red or coppery colored during the total portion of an eclipse. The red moon is possible because while the moon is in total shadow, some light from the sun passes through Earth’s atmosphere and is bent toward the moon. While other colors in the spectrum are blocked and scattered by Earth’s atmosphere, red light tends to make it through easier. The effect is to cast all the planet’s sunrises and sunsets on the moon.
Information provided by Stephen Edberg Astronomer NASA Jet Propulsion Laboratory & space.com
Zach Roberts
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