After traveling 3 billion miles in 9 years, NASA's New Horizons spacecraft flew within 7,800 miles of Pluto on Tuesday morning. “Pluto has now been explored!” team leader Alan Stern said. “We have completed the initial reconnaissance of the solar system, an endeavour started under President Kennedy more than 50 years ago and continuing to today under President Obama.” Discovered in 1930, Pluto had only been known to Earth by blurry telescope images. Rich images reveal Pluto is a world full of craters, mounds, possibly snow, and what looks like a heart. New Horizons transmitted a photo and then went incommunicado as it focused all its instruments on data-gathering as it zoomed through Pluto's system at 31,000 mph. At approximately 9:02 p.m., New Horizons will transmit all it saw back to Earth—including the sun setting behind Pluto.