A 2024 astronaut photo has revealed a naturally heart-shaped salt lake glowing pink in Argentina. The image, released by NASA for Valentine’s Day 2025, quickly caught attention because of its color and almost perfect shape.
The lake, called Salinas Las Barrancas or Laguna de Salinas Chicas, sits about 33 miles west of Bahía Blanca in Buenos Aires province. It stretches around 6 miles across and shifts in appearance depending on rain and evaporation.
This place is also shaped by ongoing salt mining and by microorganisms that thrive in extreme conditions, both of which play a role in how the lake looks from above.
A Lake That Fills And Dries Again And Again
Salinas Las Barrancas is a shallow lake that fills up after heavy rains and then dries out under strong sunlight. As the water disappears, it leaves behind thick layers of salt across the ground. According to NASA Earth Observatory, this cycle happens regularly and keeps the area rich in salt deposits.
In the astronaut image, the lighter pink color suggests the lake was nearly dry. That stage usually means higher salinity and less water, which directly affects how the lake looks.
Tiny Life Turns Nature Pink
The lake’s color comes from microorganisms that can survive in very salty water. One of them, Dunaliella salina, is a type of algae that often gives salt lakes a darker red tone when conditions are less extreme. As Lilliam Casillas Martinez, an associate professor of microbiology at the University of Puerto Rico at Humacao, explained:
“We have rainy seasons, when the salinity levels decrease [because there’s more water in the ponds]. When there’s less salt, the Dunaliella survives and the ponds look brownish-red.” she added: “During the dry season, it gets really salty. The Dunaliella dies and the archaea and bacteria take over. Then it becomes pink, pink, pink.”
Life and Salt at the Lake’s Edge
The area is also used for salt production. As mentioned in Live Science, workers extract up to 330,000 U.S. tons of salt each year, mostly using traditional methods like scraping the surface by hand between rainy seasons.
The conditions are tough. Sunlight reflects strongly off the white salt, making it hard to see and work for long periods. One worker, Chepo, described the place as harsh but familiar, saying the salt becomes part of daily life, as reported by the same.
“The salt becomes part of your life,” he said. “For someone else, it’s a hellish place, but for me, the salt flats are my home; you get used to not being able to see.”
Even in these conditions, some life manages to exist. Salt tolerant plants grow around the edges, and birds such as Chilean flamingos and yellow cardinals feed on small crustaceans rich in carotenoids. These pigments come from algae like Dunaliella and help give the birds their color.
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