Horsehead Nebula. Zooming in through the constellation of Orion to Hubble Space Telescope images of the Horsehead Nebula (Barnard 33). This nebula lies around 1600 light years from Earth. The horsehead shape, several light years across, is formed by an intrusion of dust into the emission nebula IC 434. The red glow from this nebula is due to the ionisation of hydrogen by radiation from nearby stars. Animation created using data from Hubble's Wide Field Camera 3, and the European Southern Observatory's Visible and Infrared Survey Telescope for Astronomy (VISTA).