(NASA/CXC/SAO/P.Slane, et al.) ====================================================================================== A ghostly "hand" reaching through the cosmos has just given us new insight into the violent deaths of massive stars. The spectacular structure is the ejecta from a core-collapse supernova, and, by taking images of it over a 14-year span, astronomers have been able to observe as it blasts into space at around 4,000 kilometers (2,485 miles) per second. At the very tips of the "fingers", the supernova remnant and blast wave - named MSH 15-52 - is punching into a cloud of gas called RCW 89, generating shocks and knots in the material, and...