According to NASA, “The Hubble images are a few pixels wide. But through a technique called dithering, multiple, slightly offset pictures can be combined through computer-image processing to synthesize a higher-resolution view than could be seen in a single exposure.”
“This has taken four years and 20 computers operating continuously and simultaneously to accomplish,” says Marc Buie principle investigator of the Southwest Research Institute in Boulder, Colo.
Credit: NASA, ESA, and M. Buie (Southwest Research Institute) (Click on the photo for greater details.)