Bob Fletcher, a teacher in Australia, was the first to spot a very faint object moving across images made public by NASA A brown dwarf over 100 light years away from the Sun has been discovered using a new citizen science tool that helps astronomers pinpoint new worlds lurking in the outer reaches of our solar system. Just six days after the launch of the Backyard Worlds: Planet 9 website in February, four different users alerted the science team to the curious object, whose presence has since been confirmed via an infrared telescope. “I was so proud of our volunteers as I saw the data on this new cold world coming in,” said Jackie Faherty, a senior scientist at the American Museum of Natural History and one of Backyard World’s researchers. “It was a feel-good moment for science,” said Ms. Faherty. The Backyard Worlds project lets anyone with a computer and an Internet connection flip through images taken by NASA’s Wide Field Infrared Survey Explorer (WISE) spacecraft. If...