The moon is on a blood red streak. There were two full lunar eclipses this year and there will be two next year, and I love watching the magic.
A total lunar eclipse is when our orbiting moon passes into the full shadow of the earth, and the white light of the moon turns a blood red.
When you are watching a lunar eclipse, you will see a small red arc push into the white light of the moon, gradually growing, until it takes over the entire moon, turning it bright red for over an hour, and then it gradually flows away again.
That arc is not some evil spirit eating away at the moon, like people thought in ancient times, nor is it a sign of the second coming of Christ, as some nuts are insisting about the four-in-a-row streak we’re now experiencing.
It’s simply the shadow of the earth hitting the moon as the moon lines up perfectly in a straight line with the earth and the sun. During an eclipse, the sun and moon are exactly 180 degrees apart in the sky, with the earth right between them, like three balls in a perfect row — except the sun is a softball, the earth is a grain of sand 12 meters away, and the moon is an even smaller grain of sand about an inch away from that.
This cool alignment has a cool word —a celestial alignment of three heavenly bodies is a syzygy. (I love words with lots of “y”s in in it. Another word I love is zyzzyva, which is the last word in the dictionary, and is actually a red weevil bug from the tropics.)
The light of the moon turns red for the same reason that sunsets are red. Usually the moon is getting a direct hit of sunlight that reflects down to us on earth, so it’s white. But when there’s a syzygy, there is no more direct sunlight light bouncing off the moon.
However light from the sun still ekes around the earth and refracts through our atmosphere, like light bending through lake water, and reaches the moon anyway, like that pesky morning sunlight that somehow gets under your bedroom door and through your closed curtains.
But as that sunlight bends and bounces around in our atmosphere all the colors with the shorter wavelengths, like blue, bounce away, and only the slow moving red spectrum remains, hits the moon, and then bounces back at us. It’s like a sunset, but at night.
My most memorable total lunar eclipse I witnessed was with my father. We would drive up to Lake Tahoe as a family and stay at the Sierra Club’s famous Clair Tappaan Lodge. Gigantic tree trunks hold up the entrance of this multi-level rustic lodge built in 1934. The stone fireplace is huge, and 140 people can sleep there, in boys and girls dormitories.
It’s also on Donner Pass, which gets more snowfall than anywhere else in the Sierra Nevada range, and the snow is so deep they must sometimes dig the lodge out.
It was two in the morning and my dad came to my bunk and shook me awake. We put on our snow clothes. That year the snow was so high that stepping out through the entrance was like leaving an igloo.
The snow drifts buried the tall pine trees right up to their first branches, and it flowed like a glacier down the hill to Donner Lake. The full moon was right in front of us, lighting the snowy world up better than an HMI floodlight on a movie backlot. King Wenceslas would have fit right in.
My dad had timed the ceremony better than an ancient druid. The eclipse began right after we stepped outside. The clear sky, with no light or air pollution, gave everything a sharp crisp edge. When the eclipse reached totality an hour later, the bright white world turned deep red — imagine bright red snow as far as you can see.
It was silent, calm, and still. No one was awake but us. We looked at each other, and laughed, knowing it was a moment to remember.
My dad is gone, but I try to see lunar eclipses whenever I can. My girls don’t want to wake up at 2 a.m. to see them, so I watch them alone, and none have matched up to that event in the Sierra wilderness, but I’ll keep trying.