As NASA 's Juno flew around Jupiter last week, the spacecraft snapped a photo of an object before it could make a clean getaway.  That clunky, bumpy thing at the far right edge of the frame is Thebe, the second largest of the gas giant planet's inner moons . The rarely photographed Jovian world was caught on camera May 1, during a close pass. (It's actually not quite clear whether Juno saw it coming or going.) Though the mission's JunoCam takes most of the stunning imagery from Jupiter's system, this picture came from the little-known Stellar Reference Unit instrument. The spacecraft was just 3,100 miles away from Thebe in space when it took the portrait. Each pixel represents just under 2 square miles.  "While the SRU's primary function is to image star fields for navigation, its high sensitivity in low-light conditions makes it a powerful secondary science instrument," according to NASA .  As of the latest count, Jupiter has a bevy of 115 moons .…