Flickr hosts a wide range of beautiful images, but a new project built on top of Flickr's API only focuses on photos of the night sky from amateur astronomers. The Astrometry.net project constantly scans the Astrometry Flickr group for new images to catalog and to add to its open-source sky survey. At the same time, this project also provides a more direct service to the amateur astronomers, as it also analyzes each image and returns a high-quality description of the photo's contents.

The Astrometry group currently has over 400 members, and as Christoper Stumm, a member of the Astrometry.net team, told the Flickr Code blog, the back-end software uses geometric hashing to exactly pinpoint and describe the objects in the images. When you submit an image to the Flickr pool, the robot will not just respond with a comment that contains an exact description of what you see in the image, but it will also annotate the image automatically.

While a lot of members of the Astrometry group use high-end telescopes and cameras, the Astrometry.net solver can also analyze images from consumer-level digital cameras.

While just being able to automatically analyze and catalog these images is pretty cool already, every description also contains a link that displays the image in Microsoft's WordWide Telescope.

Astronomy is one of those few scientific disciplines where dedicated amateurs can still make major discoveries and this is definitely one of the cooler applications of Flickr's API that we have seen in a long time.