This summer in central India, a mystery in color emerged.

In the space of just days, the surface of Lonar Lake turned bright pink, then returned to green.

As scientists study the cause of the event, other lakes around the world offer clues.

Australia's salty Lake Hillier is filled with microscopic pink organisms, as well as algae that turn red when stressed to help absorb light. The same type of algae is prevalent in Senegal's Lake Retba, where red hues are clearest during the dry season. Lake Urmia in Iran turns red when water levels drop and salinity spikes. Similar salinity fluctuations have been observed in Lonar Lake.

Maybe the lake will blush again, or maybe this was a one time event. Satellites like Landsat and Europe's Copernicus Sentinel-2 will be watching.