As I mentioned in my New Year’s blog post about astronomical events in 2014, a total eclipse of the moon will be visible from the U.S. on the night of April 14–15. The following table lists the various portions of the eclipse:
|Penumbral phase begins||
|Partial phase begins||
|Total phase begins||
|Total phase ends||
|Partial phase ends||
|Penumbral phase ends||
The penumbra is the outer portion of the earth’s shadow. The portion of the moon in the penumbra is illuminated by the sun, though not as much as usual. The human eye notices very little difference about the moon during the penumbral phase, so don’t expect to see anything unusual before 1:30 AM (EDT).
However, this lunar eclipse offers an opportunity to test something that I have recently written about. I have been critical of pronouncements of the supposed “blood moons” this and next year, as well as the moon appearing as blood the night of the Crucifixion. I have argued that the penumbral portions of a lunar eclipse do not appear red.
Some people have emailed me expressing their disagreement, offering photographs of lunar eclipses showing red color on the moon in the earth’s penumbra. However, these photographs are of the moon when it was very low in the sky. The redness is due to an atmospheric effect that astronomers call extinction. Any object low in the sky appears dimmer and redder than when high in the sky. During this eclipse’s initial penumbral phase, the moon will be very high in the sky, at least in the eastern U.S. I expect it not to appear red at this time. However, the moon will be very low in final penumbral phase. In fact, where I live the moon will set and the sun will rise before the penumbral phase ends. I expect the moon at that time to be red because of atmospheric extinction, not because of the eclipse. If the moon were not eclipsed, it would still appear red as it sets. This eclipse offers an excellent opportunity to see for yourself what I’m talking about.
I plan to pay more careful attention as the partial phase begins a little before 2:00 AM. Then totality begins a little more than an hour later. Totality lasts more than an hour, making this a deep, long total lunar eclipse. I’ve found that my interest begins to wane as the partial phase ends—it may have something to do with being tired!
Besides watching for the color difference that we see in the penumbral shading between the beginning and end of the eclipse, I suggest that you look for other things. Notice that as the earth’s shadow moves across the moon that the earth’s shadow is larger than the moon is. Also notice that the shadow is round. This can happen only if the earth is spherical. It is a common misconception that people in the ancient world thought that earth was flat. Ancient people used the shape of the earth’s shadow during a lunar eclipse to show that the earth is spherical.
If you can observe the lunar eclipse from a dark location, notice how much darker it is when the moon is eclipsed than when it is not. When I’ve viewed a total lunar eclipse from a dark location, I’ve found that it is easy to walk around and recognize people early and late, but not during the total portion of the eclipse. During one eclipse, I kept tripping over a dog that someone had brought.
You don’t need a telescope to view a lunar eclipse. But if you do use a telescope, select the lowest magnification, because you want to look at the entire moon at once rather than just a small part. Binoculars give a fine view. If you have a telescope, try looking at Mars—it will be the bright “star” near the moon. Saturn will be another “star” to the left of the moon and Mars. Saturn’s rings are nice, even in a small telescope.
Dress warmly and try sitting in a comfortable chair, or lie on the ground to enjoy the entire sky (a sleeping bag might help with that). By all means invite friends and family to share the time with you. Bring snacks, and make it a party! I’ll probably enjoy some Cheerwine (if you don’t know about Cheerwine, see one of my earlier blog posts.
For those of you near to the Creation Museum, we have a great offer for the night of the eclipse: you can come watch it with me at Johnson Observatory on the Museum grounds (weather permitting). In addition to the eclipse, we’ll use telescopes to look at Mars, Saturn, and possibly some fainter objects such as galaxies. The best part is that this event is free. OK, I guess being up much of the night is a cost. To attend you must register in advance, and the number of people that we can accommodate is limited, so register early. You can find out more information and register here.