Red sprites, La Silla Observatory, Chile. Visible in this night sky panoramic photograph is the Milky Way galaxy (slightly left of centre), red and green airglow along the horizon, the Small and Large Magellanic Clouds (just to the right of centre), the rosy-red glow of various star-forming regions and the faint green streak of a meteor (just to the left of the Milky Way). On the horizon to the left of the dome, a rare atmospheric phenomenon called a sprite can be seen. These events are caused by irregularities in the ionosphere, high above storm clouds, at altitudes of about 80 kilometres.