The sun flashes green for a few seconds in an extremely rare phenomenon

A man posted on his Instagram account a unique scene of the sun, in which it appeared flashing green moments after sunset.

Craig Haislip, a research assistant at Oregon State University, captured this moment on camera in Bandon, Oregon, a few days ago.

He was only 15 miles (24 km) west of Coos Bay, Oregon, when he was able to capture this rare optical illusion.

The green flash is an example of an optical phenomenon that sometimes occurs around sunset or sunrise, and does not last for more than two seconds.

What is green sun flash?

Scintillation occurs when the Earth's atmosphere causes light from the Sun to separate or refract.

When sunlight, which appears pure white, passes through the prism, it refracts and creates a stunning flash that can be seen by the human eye.

However, the flashes only occur at certain temperatures when the air at high altitudes becomes warmer, meaning the flashes are more likely to be detected over water rather than land.

The green color is produced by the refraction of light in the atmosphere, which makes objects near the horizon appear slightly higher in the sky than they actually are.

Refraction is stronger for blue and green light than for yellow and red light, resulting in a bluish or greenish color on the upper side of the sun.

How can you detect the green flash?

The flashing lasts for about two seconds and is very rare to see.

Space.com's Joe Rao explains that he has been "an avid sky watcher for more than half a century," but despite looking for the green corona on many different occasions, he has only spotted it twice.

And for those hoping to catch a glimpse of the green flash, some of Rao's tips and tricks can help.

In general, Rao says the flash is more visible on the coast than on land, so getting to a lower horizon will increase your chances of spotting it.

Cold weather and the absence of red tints in the sky will help, as reports indicate that this optical illusion occurs when the horizon appears to contain a bright white or yellow glow.

It should be noted that you should avoid looking at the sun until the last moment to reduce the risk of eye damage.