Note: This lunar eclipse is the second of four in a tetrad. I wrote about the tetrad in April 2014.
I left the house a little after 5 AM and drove the half mile to my usual dark location on the north side of town. The sky was clear and seeing was good. The Moon, low in the western sky, was already well into the partial phase of eclipse. Totality was going to occur in 10 minutes. The Sun was still not showing any sign of twilight to the east. I scanned the sky for familiar constellations. Orion was high to the south. As I looked back toward the darkening Moon, a meteor passed. That might be a good omen I thought.
I set up the camera and tripod, tried a few test exposures, and decided which settings I would use. I have a Fuji FinePix s602z that is 12 yrs old. It isn’t fancy. I come from the old school of manual cameras and film. This camera gives me a lot of control. I don’t care for fully automatic features. Plus, I get good quality digital images.
Now, a little science about a lunar eclipse. This occurs when the Moon passes through the shadow of the Earth. The Moon orbits slowly from west to east, taking about a month to go around. Earth’s shadow is rather large. Odds are good that the Moon will align such that it passes through the shadow a couple of times each year. When it is wholly within the umbra part of the shadow, it is called a total lunar eclipse. That happened this morning.
This graphic from NASA shows the Earth’s umbra, darkest part of the shadow, which the Moon passed through. It is oriented with N north pointing toward the north star Polaris in the sky as viewed in the low western sky. The Moon moved from the lower right toward the upper left as it traveled west to east. My photographs begin at point U2 when the Moon just enters the umbra and end at U3 when the Moon emerges from the umbra.
This animation, not oriented the same as the image above, shows the passage through the umbra. Tilt your head left about 45˚.
At 5:22 I centered the Moon and captured this image. It is not quite entirely within the umbra. Some sunlight still shines on the limb at the right. One minute later totality started.
The camera was set with the Moon in the upper left of the frame. At the beginning of totality, 5:23 AM, I got the first image. I waited about 15 minutes and got the center image. About 15 minutes later I got the third in the lower right. All have the same settings as above. Notice the darkening as the Moon went further into the umbra. The three images were superimposed into one using Photoshop Elements.
Since the camera was on a tripod and unmoved, the apparent movement of the Moon as well as the umbra is to the lower right due to the rotation of the Earth. During this time, the Moon has moved less rapidly to the lower right than the umbra due to its own motion in orbit. Confused? This is a problem of orbital motions and a rotating observation platform. Ask questions.
At this point of mid-eclipse, I centered the camera on the Moon and adjusted the exposure to 2 seconds to bring out more detail and the reddish color. That color is sometimes called a blood moon. It is caused by Earth’s sunsets. More about that can be found at this video link.
The Moon was now ready to leave the umbra and emerge into the direct sunlight. I superimposed three images as before.
I enjoyed a beautiful event this morning. The clear skies and crisp autumn air made this eclipse memorable. The meteor did seem to be a good omen. The Sun was beginning to brighten the eastern sky by now. I packed up my gear and headed home. In two weeks, parts of the Earth will be treated to a partial solar eclipse.
On the way, I passed a radio tower near home. The Moon had emerged more into the direct sunlight. It presented an interesting scene. I grabbed the shot and headed home for coffee with Melanie.