National Geographic News
Partially eclipsed moon rises over the desert, Ajo, Arizona. .

A partial lunar eclipse over Ajo, Arizona.

Photograph by Frank Zullo, Photo Researchers

Andrew Fazekas

for National Geographic

Published October 18, 2013

The full moon will appear to get a tiny bite taken out of it as it undergoes a shallow partial eclipse today. (See lunar eclipse pictures.)

Keen sky-watchers may notice that October's full moon, known traditionally as the Hunter's Moon, will lose just a bit of silvery luster tonight as part of its southern limb gradually dims. What is happening is that Earth's outer, pale shadow is falling on the outer edge of the lunar disk.

The celestial phenomenon, known officially as a penumbral lunar eclipse, may be a bit tricky to catch in the sky with the eye, however, since the shading effect will be quite subtle.

Armchair astronomers can watch a live feed of the eclipse, thanks to SLOOH. The Internet-based space-tracking service is broadcasting the eclipse with its robotic telescopes on the Canary Islands (map) starting at 4:30 p.m. EDT (23:30 UT).


"Penumbral lunar eclipses are the most subtle of all eclipses, but SLOOH can use techniques to bring out the shadow and reveal that something is indeed happening," said Bob Berman, an astronomer and columnist with Astronomy magazine. "Eclipses have always caught the fancy of the public ... They inspire fear, awe, superstition, you name it."

Here's what else you need to know about this lunar cover-up event:

What is a lunar eclipse?

A lunar eclipse occurs when the sun, Earth, and moon align. During total lunar eclipses, the entire moon is engulfed in Earth's darkest shadow. But during partial eclipses, the moon never completely goes dark or turns red—only a portion of its disk appears to darken slightly. (Read about a total lunar eclipse in 2011.)

"This is an eclipse where the circumstances place the moon only inside of the very light outer shadow of the Earth called the penumbra, rather than the darker inner shadow known as the umbra," said Larry Ciupik, an astronomer at Adler Planetarium in Chicago, Illinois.

"That outer shadow cone is so light that one normally barely notices the darkening moon as the eclipse progresses."

Who will see it?

In eastern North America, the eclipse will already be underway when the moon rises, with the deepest part of the event occurring at 7:50 p.m. EDT (23:50 UT). At that time, a slight shading will appear along the southeastern edge of the moon. Folks in the Mountain and Pacific time zones will probably miss out, however, because the moon will rise locally well after maximum eclipse is reached.

The eclipse will also be visible throughout South America, across Europe, and in Africa on Friday night. Meanwhile sky-watchers in Asia will get to witness the partial lunar eclipse at dawn on October 19. (Take a moon myths and mysteries quiz.)

All the stages of the eclipse will be visible across the Indian Ocean, central Asia, western Australia, Africa, and Europe.

Watch Live

When is the best time to watch?

The entire duration of the eclipse will be 4 hours and 10 minutes, commencing at 5:45 p.m. EDT (21:45 UT) tonight.

The most readily visible part of the eclipse, however, will be at 7:50 p.m. EDT (23:50 UT), when Earth's shadow is at its deepest/maximum coverage—a bit more than 75 percent of the lunar disk.

Why do lunar eclipses, even if they are partial, have such a hold on sky-watchers?

Although we understand the mechanics of lunar eclipses, they still have the power to amaze, "perhaps because eclipses are a direct illustration of those celestial mechanics," said Paul Cox, SLOOH host and outreach coordinator.

"There is something deep within us that is struck with awe when we see nature's 'big events'—and eclipses of any variety certainly fall into that category."

What if I miss this one?

Generally, between two and four lunar eclipses occur each year, so no need to fret. Next year, two much more dramatic total lunar eclipses will occur, one on April 15 and one on October 18. (Read about a 2012 lunar eclipse that occurred during a supermoon.)

Send your best Hunter's Moon and eclipse portraits to us at Your Shot.

Follow Andrew Fazekas, the Night Sky Guy, on Twitter and Facebook.

Nang Patel
Nang Patel

itss really nic page nd nic tv channel 

Meredith B.
Meredith B.

I tried to take a look at the eclipse last night but I guess I was too late. :-( The pics and video are awesome though! Maybe I'll see it next year!

l. anthony
l. anthony

Let me know when you get a good shot/video with Slooh, of Planet X, aka Planet Nibiru, aka Comet Ison and where it is now - Thanks - my email is 

Hanan Nasser
Hanan Nasser

Another beautiful natural phenomenon. Here is some significant information I liked to share:     

     A lunar eclipse is an example of an event for which we are required to perform Namaz-e-Ayaat, the Prayer of Signs... It should be performed for lunar eclipses and solar eclipses (whether full or partial), earthquakes, frightening thunder or lightening, frightening wind storms like hurricanes or tornados, receding sea water and tsunamis, landslides, and similar phenomena.

   Islam teaches its followers to remember Allah at all times, and when one witnesses such events occurring, they should serve as a reminder of God's power and might. Hence, the Prayer of Signs is mandated.


Andrew Fazekas
Andrew Fazekas

Missed the lunar eclipse worries.  Rare “Hybrid Solar Eclipse” on November 3, 2013 which Slooh cameras will be covering live from  Kenya. 

The moon glides over the sun, producing a brief annular eclipse followed by a short total eclipse. 

North Americans along the east coast will even get to see a partial solar eclipse after sunrise.  Stay tuned for details...

Andrew Fazekas
Andrew Fazekas

Waiting to see some photos of the eclipse tonight but it was a challenge to see the very slight shading on the edge of the moon.  

Next year's 2 lunar eclipses will be total and should be much more dramatic and pleasing. Let's hope for clear skies.

Marjorie Baldi
Marjorie Baldi

Even without seeing the actual changes -  its still pretty cool. Anybody watching it with their telescope and seeing the changes?

Amanda Caldwell
Amanda Caldwell

Cloudy here at home and I don't see anything distinguishable on this live video :/ I don't think the special filtering is working.

Judy Neal
Judy Neal

I wish you'd give your timings as GMT, most people around the world know what that is and how it relates to the time locally to them. I have no idea what EDT & UT are!

Shubham Srivastava
Shubham Srivastava

can anyone please let me know the time at which the lunar eclipse will be visible in India

Dave Riddell
Dave Riddell

@Susan Buttrick @Judy Neal Thx Susan but this explanation still doesn't help. There is a big wide world outside of America and as Judy says, most of the world can relate to GMT but wont have a clue how to relate to EDT!

Peggy Clark
Peggy Clark

@Dave Riddell lol and I still would not know what GMT is, I relate only to EDT cause that is the area I grew up in lol. so that can go both ways.  And I could not even see it because it was too cloudy here in Georgia and now it is so crystal clear, i am sort of pissed lol.


Trending News

Popular Stories

The Future of Food

  • Why Food Matters

    Why Food Matters

    How do we feed nine billion people by 2050, and how do we do so sustainably?

  • Download: Free iPad App

    Download: Free iPad App

    We've made our magazine's best stories about the future of food available in a free iPad app.

See more food news, photos, and videos »