Old supernova blast waves eject superfast particles. At first caught by magnetic fields, the ping-ponging particles speed up until they break free. When these speedsters later strike other matter, they make gamma rays our Fermi satellite sees. #FermiFriday https://go.nasa.gov/2CivUiz Image Description: This animation shows how magnetic fields in a supernova's blast wave boosts high-energy particles. On the left side of the image, a wispy mauve cloud represents the expanding cloud of material lef