Earth and the stars project blurred arcs of motion in this 15-minute time-lapse photograph taken from the International Space Station in March. From 240 miles above Earth’s surface, lightning is visible as bright blotches, and city lights appear as yellow streaks; the atmosphere glows in bands of yellow, green, and red as energetic air molecules interact and emit light, a process (called airglow) that is difficult to see from the ground. The circular star trails result from the long
exposure as the station, partially visible at top, orbits Earth at 18,000 miles per hour. Astronaut Don Pettit created this photo by remotely snapping 18 shots from an external camera and combining them with imaging software.