Satellites spy penguin poop on Danger Islands | Space photo of the day for July 30, 2026

Pieces of sea ice drift near Antarctica's Danger Islands in this image, acquired on Jan. 22, 2023, by the Landsat 8 satellite. Several of the islands are stained pink by guano from Adélie penguins with a krill-rich diet. (Image credit: NASA Earth Observatory/Michala Garrison)

The diets of penguins on Antarctica's Danger Islands can be seen from space. At least indirectly.

Using satellite images captured by the Landsat 8 spacecraft operated by NASA and the United States Geological Survey, scientists can track changes in Adélie penguins' diets based on the color of their guano, or droppings.