MegaCam: This is the world's largest digital camera. It's actually a combination of thirty six 8 megapixel cameras on the same telescope, the Canada-France-Hawaii Telescope on Mauna Kea. The field of view is 4 times the size of the moon.

Archive:Major telescopes, like the CFHT are very expensive to build and to run. Also, it's not always easy for an astronomer to get time on a telescope; there are a lot of astronomers with different projects and only 365 nights in a year. So it's important to get maximum value out of all the data that's taken. We save each picture that is taken with CFHT and make it available for all astronomers to use. An picture that was taken by one astronomer to study galaxies might be useful to another astronomer to study stars for example. We're recycling photons. In this particular case, we're reusing all the data that was taken with MegaCam since 2003 for whatever kind of studies (planets, stars, galaxies, nebula, supernovae, whatever) and we're looking for asteroids.

Asteroids: Asteroids are objects ranging in size from 100m to almost 1000km orbiting the sun. Most of them lie between the Mars and Jupiter. There some much further out in the solar system, and a few the orbit closer in to the sun.

Search: Our project is to search the MegaCam images for asteroids. We do this by looking for place were multiple images were taken of the same part of the sky on the same night. Asteroids move. Stars and galaxies don't. We find all the bright things in each image and ignore all the things that stay in the same place. The things that aren't in the same place are asteroids. This sounds simple, but it takes thousands of lines of computer code to do this. It also takes a lot of computing power. Each set of images takes about an hour to process and there are thousands of sets.

Verification: Unfortunately, all the computers in the world aren't as good as the human eye and a human brain's visual processing. While the computers do a fairly good job of finding asteroids, they aren't perfect. They find objects that a human instantly recognise as being a mistake. So someone has to look at each asteroid to make sure it is real. That's where you come in. We've put together images of each asteroid. We want you to look at the images, decide whether the object is real or not, and click on the appropriate button. Do as many or as few as you like. We've used this page ourselves and the first 100 or so are fun.. You see the asteroid moving through space, and you see the more distant stars and galaxies behind it.