KEY WEST, Fla. – The green flash from the Sun is a phenomenon that has been the subject of much debate, with many people dismissing it as just a myth. 

However, according to NASA, the green flash is a real phenomenon when the Sun sets or rises, and its light is refracted by the Earth’s atmosphere. Astronomers and amateur skygazers have documented this rare and beautiful event for many years.

It was captured Tuesday at sunset by photographer Maya Montana in Key West, Florida.

“Green flash is always a bonus when I see it, because it’s just unpredictable,” Montana told FOX Weather.

The green color arises due to the fact that green light is refracted more than other colors, allowing it to be seen for a brief moment after the rest of the Sun has disappeared below the horizon, NASA said. The Sun itself does not turn partly green; the effect is caused by layers of the Earth’s atmosphere acting like a prism.

To witness a green flash, you only need two things, EarthSky noted.

First, a clear day with no haze or clouds on the horizon is required.

Then, a distant horizon with a distinct edge is needed.

Although you can observe the green flash from a high building or mountaintop, it’s most commonly seen by people on beaches or in boats over the ocean.