Late last month, the Cassini spacecraft captured a remarkable photograph of the Earth and Moon as seen from Saturn. The event coincided with a project called "The Day The Earth Smiled" in which participants from 40 countries took photos of themselves waving at the ringed planet. The results have now been assembled into this awesome collage.
Cassini turned its camera towards Earth on July 19th, 2013, a time when more than 1,400 images were taken of people waving back. The images were then streamed to the NASA/JPL-Caltech people via Twitter, Facebook, Flickr, Instagram, Google+ and email.
A full size view of the mosaic — at 10,000 x 10,000 pixel resolution — can be accessed here. I've put together some screen caps at a deeper resolution: