In the Earth’s Shadow

Total lunar eclipse as seen on Tuesday Nov 8, from my backyard. Composite of 15 stills.

While partial lunar eclipses are relatively common, November 8, 2022 presented one of those rare occasions when my backyard lay in the path of totality. 

Lunar eclipses can be either simple or notoriously difficult to photograph depending on what one is trying to do. The last time I captured one was in 2021, and despite my best intents, I had slept through half of the occultation and managed to catch the second half of the event through the exit. This time the moon was supposed to set while fully eclipsed so there would be no such second chance. The next event visible in the Americas would not be until three years later in 2025. So though it was going to be cold, and the ungodly hour of four in the morning, I had to give it a shot. 

 

Imagineering

A day before the event, when I was toying with ideas for composition, I figured that I wanted to do something different from my previous capture through a scope. The final image was to be a composite wide shot showing the story of the eclipse unfolding across the sky. 

 

For this, no tracker or telescope was needed, just an SLR on a tripod would do. The event would last over 2 hours. So I hooked up a camera to external power and a headless computer which I could run remotely from inside the warmth of the house. The planetarium software that showed a virtual overlay of the path of the moon over my western horizon which was going to be my canvas. The spot had to ensure a line of sight start to finish, clear of trees and rooftops. At night fall, with camera focused and pointed and software scheduled to start shooting at penumbral contact, it was time to catch a nap.

 

Beaver Moon

When I came back out to check the scene half hour before the start, a super bright full moon was high in western sky. The light was so bright one can comfortably read a book by it. The November full moon is known as a Beaver Moon. This is the time when Native Americans and later European settlers set traps to catch beavers for their fur. But for me, the lesser known name, Frost Moon seemed more appropriate. The ground was hard and frosty, covered in dry leaves that crunched under my feet as I walked up to check on the rig. The temperature was in low 40s, but the wind-chill shaved off a few additional degrees so that the cold bit into any exposed skin. In anticipation of a cosmic drama, the camera was faithfully clicking away and the full moon had entered the frame.

In the Earth’s Shadow

It’s an incredible transformation to see the moon, in a span of 2 hours, go from a brilliant full disc to a dim orb lurking among the stars. Had it not been for modern day access to reliable and free information - no one would believe that a night that began so bright would witness such an eerie dark scene. As the full moon started disappearing in little bite size chunks, I stepped out to look at it. With every layer of luster lost, the stars in Pleiades and Taurus appeared a shade brighter in a crystal clear sky. This is when I have to take over manual control of the camera since every next shot is a smaller sliver of light which requires a longer exposure adjustment manually dialed in. 

As totality set in, the fully eclipsed moon looked like an ashen orb. I was half expecting it to disappear into the black of the night. But it persisted, looking like a smoldering piece of coal set against the blackness. Dimmer. Ominous. As if some dark spell was creeping up on humans as they slept peacefully in their little homes. 

In the longer exposure photos, now running into several seconds each, it glowed a shade of orange-red. As it hurtled towards the rooftops on the west, the first rays of daylight started to emerge on the eastern sky drawing a curtain on the scene.

Man on the Moon

At some point in the middle of this, I wondered if I were a man on the moon, what would I see in the lunar sky during the peak of totality. The earth would not be the familiar blue marble seen in magazines, of course, but a dark disc causing a solar eclipse. But what else? 

A little research told me that it would look very different from a solar eclipse seen on the earth, since unlike the moon, the earth has an atmosphere. The thin shell of air would act as a circular prism and scatter the sunlight. And as the laws of refraction predict, the red rays would bend slightly more towards the base of the "prism" than the blues before escaping back into space on the moon side. When they would arrive at the lunar surface, it would appear bathed in faint red light. 

Being more color sensitive in low light than the human eye, this redness bounced off the moon was what my camera was picking up.

In that moment it clicked, and I saw a very different view of a lunar eclipse in my mind's eye that no observer can see while earth-bound. 

The earth seen from the moon during total lunar eclipse. Source: Nasa Scientific Visualization Studio 

Further Reading:

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Nasa: Lunar Eclipse of April 15, 2014 As Viewed from the Moon