Looking south to the horizon, an astronaut aboard the International Space Station (ISS) took this photograph of most of the Caspian Sea and neighboring countries in inner Asia. Shorelines of water bodies are key features for astronauts trying to orient themselves over Earth.

The south shore of the sea appears as a nearly straight line against the dark ranges of the Elburz Mountains of northern Iran. At a right-angled corner—a telltale feature of the Caspian Sea for astronauts looking down at Earth—the coastline veers due north, where it meets the 160 kilometer-wide (100 mile) bay in Turkmenistan known as Kara-Bogaz Gol Basin (Zaliv Kara-Bogaz Gol). The narrow spit that divides this gulf from the Caspian Sea is another well-known feature. The saltwater Sarygamysh Lake lies on the Turkmenistan-Uzbekistan border, and the narrow Sor Kayduk channel in Kazakhstan shows its characteristic pink tone.

The west side (right in this south-facing image) of the Caspian Sea lies under a thin smog layer, which partly obscures the finger of the Absheron Peninsula, the center of Azerbaijan’s oil producing region. (Those facilities have previously been photographed in detail.)

Astronaut photograph ISS048-E-70125 was acquired on August 28, 2016, with a Nikon D4 digital camera using a 36 millimeter lens, and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 48 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by M. Justin Wilkinson, Texas State University, Jacobs Contract at NASA-JSC.