Stock Photo - OUTER SPACE -- 27 Oct 2014 -- The NASA Chandra X-Ray telescope observations of the Perseus and Virgo galaxy clusters have provided some new direct evidence that turbulence is helping to prevent stars from forming there. These new results could answer a long-standing question about how these galaxy clusters keep their enormous reservoirs of hot gas from cooling down to form stars. Scientists targeted Perseus and Virgo because they are both extremely large and relatively bright, thus providing an opportunity to see details that would be very difficult to detect in other clusters. The two galaxy clusters about 250 million and 50 million light years away respectively -- Picture by Atlas Photo Archive/NASA.