Interstellar grains from Stardust spacecraft

Telegraph : NASA’s Stardust spacecraft was launched 15 years ago to collect dust samples from the coma of comet Wild 2 and from the outer reaches of space. Fitted with collectors made of a silica-based aerogel, Stardust returned to Earth in 2006 with at least a million particles in separate sets of detectors. One set was open when the craft passed through Wild 2 and then closed, the other closed through the comet’s passage and kept open in a region of space suspected to have interstellar particles. To help sort the vast amounts of data, NASA turned to crowdsourcing, in which citizen scientists used their home computers to scan the collectors for the tracks left as particles hit the aerogel and became embedded. Scientists say that seven of the particles in the second set may be interstellar dust from outside our solar system.