First results from Galaxy Zoo: counterintuitive

Contributed by
Oct 17, 2007
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I've talked at length about Galaxy Zoo on these pages before: a group of astronomers has written software that extracts images of galaxies from a deep survey, and lets you classify the galaxy. It's a very cool idea.

And they have their first results back... and they're weird. Counterintuitive, even. A spiral galaxy is a disk galaxy where the stars, gas, and dust show a spiral arm pattern like a pinwheel. The Milky Way is one such spiral. You'd expect to see as many with the arms going clockwise as you would counterclockwise, for two reasons. One is that there's no reason we can think of that galaxies would spin one way over another, and the second is that if a galaxy is viewed from above as spinning clockwise, then from below it'll be seen as counterclockwise.

Yet, the results from Galaxy Zoo seem to indicate that there are more counterclockwise galaxies than clockwise! This is so odd it was written up in the UK Newspaper the Telegraph.

Personally, I'm not sure what to make of it. I'd like to see an actual scientific paper before drawing any firm conclusions! There could be some sort of odd psychological bias in how we classify objects, or it might be something in the way we choose CW versus CCW in faint, fuzzy objects. Or it might be real. If that's the case, then there's going to be some splainin' to do for sure.