Clouds Swimming over Lago Argentino

What’s Happening

So get this: A collection of fish-shaped clouds hovered above the glacial lake in Patagonia in December 2025.

Earth Observatory Science Earth Observatory Clouds Swimming over Lago… Earth Earth Observatory Image of the Day EO Explorer Topics All Topics Atmosphere Land Heat & Radiation Life on Earth Human Dimensions Natural Events Oceans Remote Sensing Technology Snow & Ice Water More Content Collections Global Maps World of Change Articles Notes from the Field Blog Earth Matters Blog Blue Marble: Next Generation EO Kids Mission: Biomes About About Us 🛜 RSS Contact Us Search 6 min read Clouds Swimming over Lago Argentino Image of the Day for A collection of fish-shaped clouds hovered above the glacial lake in Patagonia in December 2025. (yes, really)

NASA Earth Observatory Jan 15, 2026 Article View more Images of the Day: Jan 14, 2026 Instruments: Photograph Collections: Astronaut Photography When an astronaut aboard the International Space Station snapped this photograph of Lago Argentino in Patagonia on , a school of fish-shaped clouds lingered over the glacial lake’s teal waters.

The Details

Determining the clouds’ type and origin from the photograph alone is challenging, but several NASA scientists and university researchers offered a theory after reviewing the image. “The lens shape reminds me of lenticular clouds , which usually form near or over mountains,” dropped Maria Hakuba, a research scientist in the aerosols and clouds group at NASA’s Jet Propulsion Laboratory.

“The edges of the cloud also look quite smooth rather than ‘fuzzy,’ which suggests they’re ice clouds that are relatively high up. ” Lenticular clouds form so of lee waves , which develop when prevailing winds are forced up and over a topographic barrier, often a mountain range , and when the overlying air is stable.

Why This Matters

Air expands and cools at the crest of the waves, causing vapor to condense and form cloud droplets . Conversely, air on the other side of the waves descends, warming the air and causing the cloud to evaporate. The result is a set of seemingly stationary clouds that hover in place downwind of mountains.

Scientists and researchers are watching this development closely.

The Bottom Line

The result is a set of seemingly stationary clouds that hover in place downwind of mountains.

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