Image: Windswept valleys in Northern Africa
Expedition 40 Flight Engineer Alexander Gerst of the European Space Agency posted this photograph of windswept valleys in Northern Africa, taken from the International Space Station, to social media on July 6, 2014.
Astronuats aboard the International Space Station (ISS) regularly photograph the Earth from their unique point of view located 200 miles above the surface.
These photographs help to record how the planet is changing over time, from human-caused changes like urban growth and reservoir construction, to natural dynamic events such as hurricanes, floods and volcanic eruptions.
Provided by NASA