This week's image is at once fascinating and haunting: It is bacterial cells of Staphylococcus aureus, the most common cause of staph infections. (I must confess, looking at this picture makes my skin crawl a bit.) This image was taken at 50,000x magnification by the U.S. Department of Agriculture. It was also a picture of the day on the English Wikipedia several years ago.
Photo is a U.S. Government Work on Wikimedia Commons