Bad Astronomy

My new favorite lunar eclipse image

Yesterday I posted a few pictures from Monday night’s lunar eclipse – including a really cool one of the Moon and the Space Shuttle Orbiter Discovery – but of the many hundreds I saw, I think I may have a new favorite:

Sigh. How lovely! Click to enaurorenate.

It was taken by Francis Anderson, who has posted quite a few others, too. The location was Tuktoyaktuk, in the Canadian Northwest Territories. This is a small town located at the bone-chilling latitude of 69° north, inside the Arctic Circle. That explains the visibility of the gorgeous aurora borealis, the glow from solar subatomic particles as they slam into our atmosphere. Guided by the Earth’s magnetic field to the geomagnetic poles near the north and south geographic poles, these particles shear electrons off the molecules and atoms of air, causing it to glow.

But what are those columns of light reaching up from the horizon? Those aren’t part of the aurorae; those are a variant of an atmospheric phenomenon called Sun pillars. Ice crystals in the air act like mirrors, reflecting light. The geometrical shape of the crystals determines how the light is bent; in this case the glow from lights in the town bounces off of the flat surfaces of tiny hexagonal plates of ice as they float in the air, creating these ghostly shafts of light. It’s usually seen when the Sun is setting or rising, but can also occur when any bright lights are near the ground. They add a Hollywood-style searchlight/red-carpet celebration to the scene, don’t you think?

And for an astronomical bonus, on the left of the image is the constellation Leo the Lion, his sickle-shaped (or backwards-question-mark) shaped head jammed into the auroral glow up to his shoulders. Normally, the light from the full Moon would totally overwhelm those stars, but in this case, of course, the Moon was eclipsed and much fainter. I saw Leo myself Monday night, rising in the east. It’s kind of neat to think that at almost the same time I stood on my driveway in Boulder, gaping at the sky, 3500 km to my northwest this very photo was being taken.

Tip o’ the parka hood to the phenomenal website The Big Picture.

Related posts:

- A Sun pillar gooses the sky
- Didja see the eclipse?
- Discovery eclipse
- Flying through the aurora at 28,000 kph