Professional astronomers have been looking at Flickr to better understand the universe:

To get detailed images of deep space, astronomers have a couple of options…. They can either use a long exposure to capture one really detailed image, or stack multiple less-detailed images together. [Astronomer Dustin] Lang and colleagues opted for the second approach. But rather than using multiple photos taken with the same telescope, they looked to the web.  The team used a new alogorithm to stack nearly 300 images of the Galaxy NGC 5907 that they found on Flickr, Bing, and Google. They did this by “[l]iterally searching for ‘NGC 5907’ and ‘NGC5907’,” explains Astrobites.

For a photo of the night sky to be useful, though, the scientists first needed to know exactly what they were looking at. For that they turned to Astrometry.net*, a site that pinpoints exactly which patch of the sky is shown in an image. … Once they were stacked together, the images revealed faint features that offered information on the mass, age and orbitial configurations of the celestial bodies in galaxy NGC 5907–information that was not present in a single photo.

(Image via Openiduser2916 via Astronomy.net)