Bad Astronomy

Upside-down Moonset

Randy Halverson is a fantastic astrophotographer, which is why I follow him on Google+; I’m always amazed at the images he captures of the night sky.

He posted one recently that really threw me for a moment, though. Certainly the beauty is captivating, but on closer examination it revealed a prejudice of mine.

See for yourself how gorgeous it is:

Moonset over the Indian ocean
The Moon setting into dappled waters…but what’s wrong with this picture? Click to embiggen.

Image credit: Randy Halverson, used by permission

That is the Moon setting over the ocean, the water surface reflecting it like a pylon made of light itself. The cloud just below the Moon is dappled in light and shadow, and the symmetry of its curve is lovely to behold.

I was gaping at this, and then the stars caught my attention. I know my way around the sky, and immediately recognized Orion directly above the Moon. But the orientation of the constellation confused me; it was more than just on its side, it was starting to flip over, nearly upside-down to my eye.

My first thought was, “Where the heck did he take this shot?” And then I saw the picture caption—“Orion and Moon set on the Indian Ocean”—and I laughed. Of course! I was seeing this picture through my northern-hemisphere bias.

He took this shot on Mar. 17, 2013 near Kalbarri in Western Australia, about 27° south of the Equator. From that location on our spherical planet, things look different. I’m used to Orion oriented very differently. From home, when Orion’s high over the southern horizon, the legs are down and he stands upright. He moves left to right as I face south.

But in the southern hemisphere it’s all wonky. He rises to the right as you face north, is standing on his head when he’s high above the northern horizon, and moves right to left.

That’s seriously weird to my borealic brain. I was in Australia a few years ago, and the two things that totally freaked me out were seeing Orion upside down, and the crescent Moon facing the wrong way at sunset. When you’re looking at the same objects you always see, but essentially upside-down compared to what you’re used to, things get all swapped and weird. Left is right, up is down… but the stars still rise in the east and set in the west. The whole Earth, at least, spins the same way.

Still, living on a round ball is distressing when you’re reminded of it in this way. But it’s a great reminder that the Universe is the way it is, and it’s our own ossified sensibilities that give us grief about it. Once you shake that off, the depth of its beauty becomes even more profound.

I’ve written about Randy’s work many times; you can see more in these posts: