One meteorite crash thousands of years ago, created a mysterious lake. Its water can turn pink and red due to a strange phenomenon under the surface

Lonar Lake in Maharashtra is not an ordinary lake. Hidden inside a vast impact crater, the unusual body of water was created when a meteorite struck the Deccan Plateau thousands of years ago. What makes it even more unusual is what happens to the water: depending on the conditions beneath the surface, it can shift from its familiar green appearance to shades of pink and red.

Located in Maharashtra’s Buldhana district, Lonar Lake sits inside a roughly circular crater formed by a high-velocity meteorite impact.

The crater is about 1.8 km wide and around 150 metres deep, according to the Government of India’s Incredible India portal. The impact occurred in basaltic rock associated with the Deccan Traps, giving the site unusual geological importance.


The exact age of the crater has been reported differently over time. Earlier studies put it at around 52,000 years, while later research revised the estimate to about 570,000 years.

For scientists, its combination of an impact crater, basaltic surroundings and unusual water chemistry makes Lonar an important natural laboratory.

Why does the water turn pink or red?

The lake’s colour is closely linked to the extreme conditions in its water.

Lonar, which is the world's only known hypervelocity impact crater, is both saline and alkaline, unlike an ordinary freshwater lake. Because the lake has no natural outlet, evaporation can leave behind high concentrations of salts and minerals.

These conditions support microorganisms that can survive in such an environment. When temperature, water levels, salinity and other conditions change, different microorganisms can become more prominent.

The lake’s green appearance is associated with algae and other aquatic organisms. Pink or red shades, meanwhile, have been linked to salt-loving microorganisms such as Halobacteria, which produce pigments that can give the water a striking colour.

In 2020, Lonar attracted worldwide attention after its water turned noticeably pink. Scientists linked the change to factors including hot weather, falling water levels, increased salinity and biological activity.

A strange ecosystem beneath the surface

The unusual colour is only one part of what makes Lonar scientifically interesting.

Its highly alkaline, mineral-rich waters support the life of microorganisms that are adapted to survive in extreme conditions. The lake also has different chemical and oxygen conditions at different depths, which creates habitats for organisms capable of surviving where many other forms of life would struggle.

This is what has made Lonar important to research into extreme environments and astrobiology. Scientists study such ecosystems to better understand how life can survive under harsh conditions.

The lake’s geological setting has also drawn comparisons with extraterrestrial landscapes, including craters on the Moon and Mars.

More than a geological curiosity

Lonar is surrounded by forest, old temples and other historic remains. The crater area is also known for migratory birds and other wildlife. A roughly 6-km trail around the crater offers views of the lake from different elevations and passes through forested sections, ruins, streams and temples.

The lake was declared a Ramsar site, recognising its importance as a wetland.

Its changing appearance, unusual chemistry and meteorite-created crater have therefore made Lonar a place where geology, biology and history meet.