Westerlund 1 is the biggest and closest “super” star cluster to Earth. New data from NASA’s Chandra X-ray Observatory, in combination with other NASA telescopes, is helping astronomers delve deeper into this galactic factory where stars are vigorously being produced. Westerlund 1 is the biggest and closest “super” star cluster to Earth. New data from NASA’s Chandra X-ray Observatory, in combination with other NASA telescopes, is helping astronomers delve deeper into this galactic factory where stars are vigorously being produced. Astronomy Phys.org – latest science and technology news stories