Spanning more than 1,000 kilometers across eight European countries, the Alps are among the planet’s largest and highest mountain ranges.
Spanning more than 1,000 kilometers across eight European countries, the Alps are among the planet’s largest and highest mountain ranges. The terrain is home to thousands of glaciers, including the range’s largest—the Great Aletsch Glacier (Grosser Aletschgletcher) in southwestern Switzerland. But like many glaciers in the Alps, the Aletsch is retreating and thinning.
Change across the past four decades is visible in this image pair. The TM (Thematic Mapper) on Landsat 5 captured the left image in September 1984, and the OLI (Operational Land Imager) on the Landsat 8 captured the right image in August 2024.
As of March 2025, it was still too early in the year to acquire a new image without seasonal snow obscuring the glacier. Even in these late-summer scenes, minor differences might still be related to snow. Even so, changes to the length and width of the glaciers are clearly visible.
Read more at NASA Earth Observatory
Image: NASA Earth Observatory images by Michala Garrison, using Landsat data from the U.S. Geological Survey.
