Lunar Eclipse, August 28
Published on Aug 26, 2007 at 1:09 am.
8 Comments.
Filed under astronomy, moon, observing.
The annual email urban legend about Mars has been making its way around the internet again. And, of course, as I said a few weeks ago, it is still wrong. But, there is going to be something interesting going on Monday night, and that is that the Moon is about to be full. And, this time, it is going to be almost directly opposite the Earth from the Sun. Yes, Full Moon occurs when the Moon is on the opposite side of Earth from the Sun, but this time it will be almost directly opposite — close enough, in fact, for the Moon to pass through the Earth’s shadow. That means that we’ll get a total lunar eclipse!
The Moon shines by reflected light, so you might expect it to just disappear when it is in the Earth’s shadow, but that doesn’t really happen. I wrote about that back in February of this year. The Moon will normally look orange or red when it is eclipsed due to light refracting around Earth in its atmosphere. If you were standing on the Moon looking back towards Earth, it would look like a large ring of twilight in the sky. That light shines on the Moon, and so we on Earth looking back at the Moon see it reflecting that orange/reddish light.
If you want to read more about eclipses, you can read my prior postings linked above or this one. I also posted some photos of the last lunar eclipse visible from where I live. The Goddard Spaceflight Center has a special web page for this particular eclipse. They are going to have a live webcast for the eclipse, even.
But, of course, you might want to go out and observe it yourself. That is easy to do. You do not need a telescope or binoculars to observe the eclipse. It can be done with the naked eye. However, if you do have a pair of binoculars, don’t hesitate to take them with you. Binoculars are not needed to observe the eclipse, but they can help. You’ll more easily see the edge of the shadow of the Earth falling on the Moon as the Moon goes into and comes out of eclipse. But, you will also need to be in the right place on Earth and at looking at the right time to see the eclipse. Lunar eclipses are generally easier to see than solar eclipses. First of all, solar eclipses need special equipment to safely observe the partial phases of the eclipse. And, a total solar eclipse requires that you be in exactly the right spot on Earth. There is a very narrow strip across Earth where such an event can be observed. Even partial solar eclipses are more restrictive than lunar eclipses. Since a lunar eclipse is the Moon passing into Earth’s shadow, if you are anywhere on Earth where the Moon can be seen at the time, then you’ll see the lunar eclipse. That means that basically half of the planet can see the eclipse. Actually, over half of the planet can see some part of the eclipse, since it takes a few hours and the Earth rotates some during that time period. This particular eclipse at about 8:51 UT and ends at about 12:24 UT (at least for the the umbral phase). The UT designation stands for Universal Time. For non-astronomers, that is basically Greenwich Mean Time. Translating that into Central Dalight Time for my readers here in the United States, the eclipse starts at 3:51am CDT (Central Daylight Time). The Moon starts to come out of eclipse at 6:23am CDT. The partial phase of the eclipse would end at about 7:24am CDT. However, for those of us in the Dallas/Fort Worth area, the Moon sets before the eclipse is over, so we won’t get to see the whole thing. Moonset here is about 7:09am CDT. If you want to find out the particulars for observing this eclipse from some place other than Texas, the US Naval Observatory has a lunar eclipse calculator web page that will give you the particulars for your location. The diagram below, from Fred Espenak at the Goddard Spaceflight Center, shows the passage of the Moon through Earth’s shadow for this eclipse.
So, that means that here in Texas, we have to go out before dawn (sunrise is 7:01am CDT in Fort Worth), and we still don’t get to see the entire event. The last lunar eclipse (the one that I posted photos of), the Moon was already in eclipse when it rose, so we didn’t get to see that entire event, either. But, that’s OK. I’ve seen lunar eclipses before, and I will again. It just turns out that this year, Texas is right on the edge of where the lunar eclipses can be seen. Here is a diagram showing the conditions of visibility for this eclipse:
From this diagram, you see that about the best place to watch the eclipse is in the middle of the Pacific Ocean, like in Hawaii. Throughout most of the Americas, the Moon is setting during the eclipse (either while eclipsed or while going into or out of the eclipse). In North America, the best places to see the entire event will be along the West Coast (California, Oregon, Washington, British Columbia), Alaska, or the Yukon. Australia and the eastern part of Asia see the Moon rising during some stage of the eclipse (much like we saw in Texas for the March eclipse). Africa and Europe don’t set to see this eclipse at all. It will be happening during the daylight hours for both Europe and Africa, and the Moon will be on the other side of the Earth. NASA’s Goddard Spaceflight Center has a web site where you can find more information like this for other eclipses in the future (or past). That, plus the USNO lunar eclipse calculator that I mentioned earlier will allow you to determine whether or not you’ll be able to see any future eclipse, and when the eclipse will happen.
So, if you are anywhere that can see this coming eclipse, then you should go out and look for it. This isn’t a once in a lifetime event, but it is still fun to watch lunar eclipses.
-Astroprof
Images courtesy of Fred Espenak (NASA, GSFC)
P. Winters on August 27, 2007 at 4:45 am: 1
Dear Prof,
When writing about the Internet, the word should always be capitalized, as though it were a country or language. Thanks for the eclipse information.
JB Cossart on August 27, 2007 at 12:10 pm: 2
Dear Professor,
I am an editor for The Issue (www.TheIssue.com), a blog newspaper. We found your post on the eclipse particularly well written and so we have featured a caption and a link to your website on today’s issue.
Thanks for your insight!
Cheers,
JB
World News | The Issue
Lunar Eclipse Tonight on August 27, 2007 at 12:47 pm: 3
[…] In all the posts about tonight’s lunar eclipse, it’s easy to get the impression that you need to go out tomorrow night to see it. […]
Astrolink [Global Edition] » Lunar Eclipse Tonight | Latest astronomy news in 11 languages on August 27, 2007 at 1:23 pm: 4
[…] In all the posts about tonight’s lunar eclipse, it’s easy to get the impression that you need to go out tomorrow night to see it. […]
Debbee on August 28, 2007 at 1:23 am: 5
I was told that Mars would appear to be as large as the fullmoon, so look as if we have two moons. Was this just a prank e-mail?
Astroprof on August 28, 2007 at 4:03 am: 6
Debbee, that is an email hoax. See my August 8 entry to read more about it.
4mauihawaii on August 28, 2007 at 6:18 am: 7
I am in Maui Hawaii out in the country. I am the most amazing perfect view of the eclipse right now. It is 1:16 AM. I have been watching for an hour. I just wanted to share the experience. Digital camera cannot capture. What a blessing.
sunrise calculator on March 24, 2008 at 12:45 am: 8
Very interesting article. Although I missed it, I enjoyed learning more about lunar eclipes.