Lunar Eclipse | First of a Tetrad

Joel 2:31: “The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the LORD comes.”

That is an ominous sounding excerpt from the bible. Does it have anything to do with the coming lunar eclipse early in the morning of April 15, 2014? The Moon will probably appear red during the totality part of the eclipse. That is about the only thing. Don’t worry about an impending apocalypse. So, why is this lunar eclipse drawing special attention?

What is a Lunar Eclipse?

These occur when the full Moon passes through the shadow of the Earth. It happens on average a couple of times a year. Earth is positioned between the Sun and the Moon. This brief 2 minute video from the folks at the Goddard Space Flight Center will illustrate the mechanics of a lunar eclipse.

As you may have noticed, the Sun is not turned to darkness during a lunar eclipse, at least for us on Earth.

What is a Tetrad?

This total eclipse will be the first of four consecutive total lunar eclipses within the next two years. That is why a tetrad is so special. It has been almost 10 years since the fourth one of the previous tetrad. The next tetrad will not occur until 2032. See table. Let this 4 minute video from Science at NASA explain more about this idea.

All four total eclipses of this tetrad will be visible in North America. That is particularly unusual. Normally, the four would be visible from four different regions of the earth.

What Shall I look For?

The following diagram shows the orientation of the Sun, Earth with shadow, and Moon during an eclipse. It is not drawn to scale. There is a faint portion of the shadow forming a ring called the penumbra and a smaller darker shadow region called the umbra. Anywhere in the penumbra, one could look from the Moon and see part of the Sun near the Earth. Anywhere in the umbra, one would see the Sun entirely blocked by the disc of the Earth. The umbra is the area where a total lunar eclipse occurs. A partial eclipse occurs if the Moon is in the penumbra.

wiki commons

My desktop planetarium software allowed me to make this 1 minute video of the passage of the Moon into the shadow of the Earth. The actual events depicted in the video take about 5 hours start to finish.

When Shall I Look and Where?

The eclipse will be visible in North America, Central America, and the western part of South America. It will be high in the southern sky. It takes a long time for the entire sequence. There is no rush to see a brief event. The only problem is the time of the night. I live in the central time zone of the U.S. The umbral phase, when totality nears, starts at about 1:00 AM. Totality begins at 2:07 AM and ends at 3:25 AM. Mid-eclipse, when the moon should be reddest, is about 2:45 AM. Those are not convenient hours to be outside watching the sky. But, if the sky is not cloudy, I will probably make the effort to witness it. This is not something one sees often. Here are the times for the other time zones of the country.

Sky & Telescope Magazine


One More Thing

This week Mars is closest to Earth during its orbit. It rises a little before the Moon on the night of the lunar eclipse. It will be very bright and to the upper right of the Moon during the eclipse. Many amateur astronomers are viewing Mars at this time of closest encounter with Earth. Many details are visible such as the polar caps, clouds, and seasonal dust storms. This image is by Fabio Carvalho and Gabriela Carvalho was obtained using a high-speed digital camera and 16-inch diameter telescope from Assis, Brazil. It appeared on the award winning site Astronomy Picture of the Day. Click the image for their url and explanation of the image.

Copyright: Fabio Carvalho and Gabriela Carvalho


Are We Doomed?

What do you think? Are we in danger of the end as suggested by some? There are many web sites claiming bad things will happen. I am not linking to any. Google search on your own if you want to read them.

I don’t think we have anything to fear. This natural event has happened many times before. It will do so for millennia to come. I hope your skies are clear and you get up to see it. If you don’t plan to watch the entire phase of totality, at least take a look during it. It will be an awesome sight.

28 thoughts on “Lunar Eclipse | First of a Tetrad

  1. I don’t think we have anything to fear except loss of sleep from staying awake in the middle of the night.

    Your discussion of tetrads, which recur every so often, reminded me of what are called twin primes, which is to say prime numbers that are 2 apart from each other. Some examples are 17 and 19; 29 and 31; 71 and 73. No one knows if the number of twin primes is finite or infinite.

    What we know will continue is some people’s attribution of dire consequences to natural phenomena that have nothing to do with the purported dire consequence.

  2. This wonderful report brings echoes of my friend Bob Schwartz to mind. I read your post in his voice. If we were hiking together, rest assured that our camp would be in the best viewing spot available. Sadly the mid-Atlantic weather forecast is for rain and Bob is no longer with us. I’m afraid the eclipse is going to be a bust for me.

  3. Reblogged this on A fork in the road and commented:
    This is a most informative and excellent read. Hikers tend to be in areas away from ambient light pollution where the cosmos is more vivid, and certainly more interesting than in urban areas.

  4. Some of the best things EVER happen in the wee hours of night, and are definitely worth staying up for! This is no exception! Fortunately, I’m currently out in the middle of nowhere with gorgeous dark skies. Unfortunately the weather forecast is calling for thunderstorms early on in the night, with a then slow steady rain overnight. Regardless, I’ll be awake and catching as much of this as I possibly can. Thanks to your excellent post, Jim, I now know when and how to best view this. Thanks!

    As for the Doomsayers, on the next day when the world doesn’t end, they’ll be moving on to the next event sure to bring about ‘death and destruction’. It’s really all they have.

    • Maybe there will be a brief opening in the clouds. I’m still unsure what to expect here.

      There will always be another conspiracy or doomsday event to follow. Entertaining.

      Thanks for coming by.

  5. This reminds me of an astronomical oddity that I have marveled over ever since I was a teen-aged science fiction fan, i.e., that Earth’s single moon should just happen to be of a size and at a distance that it and the sun appear to be the same size. It didn’t have to be this way, as we now know from evidence within our own solar system.

    Of course the phenomenon is more apparent with a solar eclipse than a lunar eclipse. When that happens, the two appear to fit precisely. It’s a circumstantial thing and one which I’m sure contributed to superstition and perhaps even delayed science. If the moon had been substantially larger or smaller, it seems to me, it might have inspired more curiosity about its true nature. Instead, to the unscientific mind it appears to be purposeful.

    • You raise a very interesting point. The moon hasn’t always been this distance from earth. It was closer in the past. It recedes now at a rate of about 3.8 cm per year. Total solar eclipses in the past would last a little longer than today due to the slightly larger appearance of the moon covering the sun’s disc.

      Today, the moon, at its farthest point in orbit, can’t quite cover the sun and we get annular eclipses.

      Sometime in the distant future the moon will always appear too small to cover the disc of the sun. This document calculates nearly 600 million years from now.
      Another I read calculated closer to 700 million.

      Thanks for raising that point.

  6. Luckily we are in a more fortunate time zone for this. I hope the clear night skies last even one day longer than the NWS is forecasting right now! It’s been beautiful the last few days, with Mars bright and red, even with the moon lighting up the sky right now. So bright it seems to be keeping birds awake – heard a killdeer the other night flying by, and some other bird I can’t quite ID, but not an owl. I’ve seen a total red lunar eclipse once before straight through and it was glorious. Hope I can again, and that your skies are cooperative that night. Worth setting the alarm for. Considering how often these occur, it’s surprising how infrequent the conditions have been just right for it, over here in the PNW anyway. Thanks for the eclipse alert 🙂

    • Today, the hourly forecast says that morning will be 25% cloud cover. That’s ok. But, it is to be in the 27˚ range. I may do some viewing through a window. Maybe Melanie will go on a date with me in her car. It has a sunroof. That would be fun…for about an hour at most. I will see if I can talk her into it.

      On a walk recently, we heard a blue jay making a ruckus. As we neared, we spotted a big barred owl about 100′ away. It turned to us, looked intently, and flew away. Beautiful. We hear them on occasion at night. I saw one out the back window briefly several years ago.

      Thanks for visiting.

  7. Family was talking about this yesterday … the first video is a great explanation … so too bad I’m late to this post because family is gone.

    • You might be better off to get up at 4 am at mid-total eclipse and watch as the moon emerges back into light by 4:30. You can get more sleep that way.

      • I ended up remaking our bed so that our heads were at the foot of the bed–and we didn’t draw the blinds. We could then see the eclipse as we drifted in and out of sleep. It was lovely–with a very dreamlike quality.

        • You are very clever. I like the idea of the dreamlike quality. I was us moments before the moon went into the shadow completely. I got a few pictures to share later. Mars was up to the right beaming proudly. Porrima was attending very close to the moon.

          I am glad you had a good experience.

  8. We may be in luck. The skies were starting to clear at sunset. I’ve not been out again to check, but the way the wind is howling, we may well have clear skies for viewing. I’m a great fan of eclipses and comets, so I’ll be out there if conditions allow.

    As for the prophecies and such, the last big event was back in 2011, when Harold Camping announced the end of the world. It didn’t happen, of course, so he recalculated the date. Again, it didn’t happen. Now, Harold has died, and I suppose the fellow in San Antonio who’s hawking his version of Apocalypse Maybe is hoping to take his place.

    There’s a great book from the 50’s called “When Prophecy Fails.” Three pretty well-respected social scientists studied one of these failed cults, and drew some interesting conclusions. I suspect it would be just as relevant today.

    I don’t want to get too far into this on your blog, but it is interesting that the fellow pushing the blood moon story line is basing it all on an interpretation of scripture that’s pretty “out there”. I know quite a few of the faithful who are rolling their eyes right along with everyone else.

    The bottom line to some of this is that our modern prophets of doom have discovered there’s profit in doom – and they’re hyping accordingly. 😉

  9. Beautiful sight from Angleton, Texas, –So very glad I am able to see this!!!!!. If it is connected to prophecy, only time will tell, at least we all know one thing that science can not predict—- that is the exact time of the return of Christ… Scriptures do bring a blood moon into perspective, and it is true, we have lost many trees to fires, we have wars and rumors of wars, we have earthquakes across the globe, true enough times are turbulent, but no man knows the hour of our saviors return. This in itself personally, keeps me in check, keeps me from expressing road rage, keeps me from some tons of sin, attempting to keeping it real, attempting to be faithful, and at the most—hopeful, —-, well, most of the time, for in all honesty, truly, I fail miserably at being a Christian on a daily basis. But, Thank God, for His mercies are new every morning! Alana from Angleton, Texas.

    • I am glad you were fortunate to see it. I was up, too. Our skies cleared. It was gorgeous. I’ve seen several in my lifetime. The red color showed lightly painted across the face.

      I appreciate your comments about the signs and signals to the return of Christ. None of us knows for certain about that. I am science trained. The need for evidence and testing and knowledge of the ways of God’s natural world carry enormous influence on me.

      Thank you for your comments. We struggle daily to be good people. Yes. Thank God for our mercies.

  10. And it was beautiful, here in League City, just up the road from Alana. Cold watching, with the winds still up and the temperatures down, but worth every minute.

    By the way – you may or may not know that the Japanese don’t see a man in the moon. They see a rabbit!

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