Remember Galaxy Zoo? It's a project using professional images of galaxies, but has citizens -- that means you! -- classifying them. It's the crack cocaine of the internet; once you start it's hard to stop.

Well, the folks in charge of it have decided to use that addictive quality to their advantage. This week is the IYA's 100 Hours of Astronomy effort, where observatories and other ventures are doing all sorts of outreach including live observations, all spanning the 100 hours of time from April 2 - 5. And Galaxy Zoo wants to classify 1,000,000 galaxies in those 100 hours! Sound crazy? They're already halfway there![Incidentally, in the time it took me to write this blog entry 9000 more have been classified.] If you've fiddled with Galaxy Zoo before, you know how much fun it is: all you have to do is take a simple test so that they know you can classify galaxies (into elliptical, irregular, and spiral (both clockwise and anticlockwise)) and once you do, off you go. They've made some improvements to the process since I last wrote about it, so even if you've been there before, it's time to revisit. It's fascinating, it's fun, and you're using real data and doing a real contribution to science. So get in there and start classifying!