Where on Earth: Lake Darodzan

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What produces the white areas visible in this image of Lake Darodzan in Iran?

Produced by the Space Telescope Science Institute’s Office of Public Outreach in collaboration with the NASA Earth Observatory (https://earthobservatory.nasa.gov/).

Story adapted from Image of the Day post by Justin Wilkinson, Texas State University, JETS Contract at NASA-JSC: https://earthobservatory.nasa.gov/images/91860/lake-darodzan-in-sunglint

  • Image of Lake Darodzan in Iran taken by Expedition 52 Crew, International Space Station
  • Written by Katherine Porter
  • Designed by Dani Player
  • Music from Yesh Music (ASCAP)

A collage of satellite imagery. Text, Where on Earth?
A lake amidst mostly barren desert terrain partially covered in patches of white, resembling ice cover. What produces the white patches in this photograph of Lake Darodzan, Iran? A. Salt. B. Sand. C. Coral. D. Sunlight.
The correct answer is sunlight. The white patches are labeled Sunglint. Zagros Mountains are labeled at the top edge, with fields and the Kor River in a valley below with light vegetation feeding the lake. A dam wall is labeled on the opposite side of the lake, and the river beyond continues to Darodzan. Sunlight on Lake Darodzan, Iran, photographed by Expedition 52 Crew, International Space Station. Lake Darodzan is a human-made lake located along the Kor River in the Zagros Mountains of Iran. As winds disturb the surface of the lake, sunlight reflects off the water in different ways. The reflections produce a variety of patterns, including the bright white, mirror-like gleam of sunglint.
Sunglint is an optical phenomenon that occurs when sunlight reflects off the surface of water at the same angle that a satellite sensor-- or camera-- views it.
This photograph, taken by an astronaut aboard the International Space Station, captures sunglint on the lake at a particular instant in time.
The pattern of white would be different had the photograph been taken a second later, or from a slightly different angle.
Zooming out from Lake Darodzan in Iran to the entire Earth in space. Music courtesy of Yesh Music, ASCAP.
Where on Earth?