... Fractal Interstellar Dust Up Close . ... Dust usually shows its presence by blocking out light emitted from stars or nebulae behind it, sometimes creating the illusion of a horse's head or a sombrero hat. ... Centaurus A: X-Rays from an Active Galaxy . ... Above, false-color x-ray images from the Chandra Observatory reveal details of this remnant pulsar's x-ray bright nebula along with emission from a spectacular jet of high-energy particles. Aurora Over Cape Cod . ...