The sun sets behind the Earth as astronauts watch aboard the International Space Station (ISS).

One of two ISS Expedition 13 astronauts currently serving aboard the station snapped this image of an orbital sunset during one of 16 orbits 213.1 statute miles (342 kilometers) above Earth. The maintain its orbit, the ISS flies at a speed of about 17,500 miles per hour (32,500 kilometers per hour).

That speed carries the ISS around a complete orbit in 90 minutes, meaning that every 45 minutes its astronaut crew catches a sunrise and sunset.

ISS Expedition 13 commander Pavel Vinogradov and flight engineer Jeffrey Williams are currently serving aboard the space station. The two astronauts boarded the ISS on April 1 and took charge a week later when their predecessors – Expedition 12 commander Bill McArthur and flight engineer Valery Tokarev – returned to Earth with station visitor Marcos Pontes, Brazil’s first astronaut.

The Expedition 13 crew are serving a six-month mission aboard the ISS.

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-- Tariq Malik

Credit: NASA/JSC.