Over the past week, the internet has been getting excited over a hot-pink lake in the heart of Melbourne. And despite what science fiction nostalgia it may conjure up, this is not a scene from “Ghostbusters” or “The X-Files.” This is very much a real, natural phenomenon that occurs all over the planet. It’s what happens when the only thing living in a supersalty lake is a single-celled, salt-loving microbe that makes pigments called carotenoids.

“It’s the equivalent of having a desert, pink lake right in Central Park,” said Mark Norman, a conservation biologist for Parks Victoria, which manages the lake. “It’s quirky and fascinating, and I love it when natural systems do something that is so large scale that it just blows everybody away.”

The lake turned pink last week, and is expected to return to its normal color when the weather cools down and rains return for Australia’s winter, which starts in June.