Galaxy Zoo Project asks volunteers to classify images of galaxies based on their size, shape and colour.
To understand how galaxies formed we need your help to classify them according to their shapes. If you're quick, you may even be the first person to see the galaxies you're asked to classify.
The launch of this new version of Galaxy Zoo, the 4th, comes just a few weeks after the site's 5th birthday. It all started back in July 2007, with a data set made up of a million galaxies imaged by the Sloan Digital Sky Survey, who still provide some of the images on the site today. With so many galaxies, we'd assumed it would take years for visitors to the site to work through them all, but within 24 hours of launch, we were stunned to be receiving almost 70,000 classifications an hour. In the end, more than 50 million classifications were received by the project during its first year, contributed by more than 150,000 people.
That meant that each galaxy was seen by many different participants. This is deliberate; having multiple independent classifications of the same object is important, as it allows us to assess how reliable our results are.
For example, for projects where we may only need a few thousand galaxies but want to be sure they're all spirals before using up valuable telescope time on them, there's no problem - we can just use those that 100% of classifiers agree are spiral.