LUNAR ECLIPSE, Thursday Aug. 27
All times shown are Universal Time.
For Pacific Time, it's 7 hours earlier; Mountain, 6 hours; Eastern, 4 hours.
Image: © NASA
By Zachary Singer
If you haven’t seen one, don't miss the lunar eclipse, this Thursday evening, August 27th!
While not as rare as a solar eclipse, these events don’t come along very often. And unlike a solar eclipse, you don't need filters to protect your eyes.
What You’ll See
During a lunar eclipse, the Moon’s orbit takes it gradually into Earth’s shadow. As the Moon slips farther into this area, the Moon’s surface naturally darkens—during the deepest parts of the eclipse, these shadowed lunar areas may take on a deep red or copper color, giving an eclipsed Moon its “Blood Moon” moniker. Having seen many of these events, I can tell you it’s pretty cool!
Most folks notice an eclipse starting when the Moon first enters the deeper, sharp-edged part of Earth’s shadow, which is known as the umbra. At first, you’ll just see a tiny little “bite” taken out of the edge of the lunar disk. As the eclipse progresses, and the Moon moves towards the center of the shadow, that little bite grows larger and more distinct, until the Moon arrives at the most centered part of the eclipse. This is where the shadow is darkest and most colorful. During a total lunar eclipse, the Moon will lie entirely within Earth’s shadow.
For the August 27th eclipse, the Moon will remain slightly off-center from the Earth’s shadow, so while we won’t “officially” get a total eclipse, it’s going to be close enough to get a similar effect, and only a small sliver of the sunlit area will remain.
As the eclipse continues, the Moon will slowly leave Earth’s shadow, with more and more sunlight striking the lunar surface, and the shadow shrinking… Eventually, the Moon leaves the Earth’s shadow, returning to its normal, full-Moon appearance.
How to Look
Happily, your eyeballs alone are enough to see lunar eclipses and enjoy them! But over the years, I’ve found that a good pair of regular 7x35 or 7x50 binoculars are nice to have, too. These can help you see more of the details in the Moon’s shadowed areas and appreciate the subtle changes in hue across the lunar surface. They’re also great for seeing the small “bite” of shadow as the Moon enters or exits the umbra more distinctly! Check out some binos HERE!
A small, 80mm or 100mm (3- or 4-inch) telescope can be lovely too, and bigger telescopes are wonderful—but still, don’t forget to stop and take it all in with just your eyes. Check out a good starter telescope HERE!
When to Look
For folks in the Mountain Time zone, you’ll see that first “bite” at approximately 8:35 PM (so 9:35 PM Central and 10:35 PM Eastern). In the Mountain Time zone, the Moon will still be quite low, only about 10° above the southeast horizon—it will be much higher for observers in the Central and Eastern zones…
Unfortunately, this means our friends in the Pacific Time zone will see the beginning of the eclipse either very low on the horizon (Los Angeles) or miss the beginning altogether (Seattle)—but you get to see something unusual: a rising, partially eclipsed Moon! You will need a clear horizon to the southeast. (Seattle folks—start watching around 7:53 PM your time and expect an eclipsed moonrise within the next few minutes, depending on local terrain.)
We will all get to see the deepest part of the eclipse! That’s at around 9:14 PM Pacific, 10:14 PM Mountain, 11:14 Central, and 12:14 AM (on August 28th) Eastern. Again, this is when we’re most likely to make out any unusual coloration—some eclipses are very deeply colored, and some, well, not so much—but the dark shadow is memorable, even without the red hue. (Along with how deeply the Moon is within Earth’s shadow, other things come into play as well, like how much dust, smoke, or humidity is in our atmosphere during the event.)
As the eclipse continues past its deepest point, increasing sunlight strikes the lunar surface, while the shadowed area shrinks… The last little bite of shadow will seem to disappear quickly, after about 10:40 PM Pacific, 11:40 PM Mountain, 12:40 AM (again, on the 28th) Central, and 1:40 AM Eastern. The show will be over, just a few minutes after that.
A Deeper Explanation, if You’re Curious
Technically speaking, the eclipse actually starts when the Moon first enters the penumbra—the blurry, outer edge of Earth’s shadow—causing very subtle darkening about an hour before the first “bite” out of the umbra. Ordinarily, you might perceive a bit of this darkening not long before the umbral stage, described above. This time though, for folks on the Great Plains and west of there, either evening twilight or the horizon itself will block the view, but the same opportunity exists for the hour after the last bite, and the Moon will be in a good position for this to be visible.
Wishing you clear skies!
