Enjoying EarthSky? Subscribe.

143,628 subscribers and counting ...

How to see the legendary green flash

Green flash on upper part of sun, as seen by EarthSky Facebook friend Jim Grant in Ocean Beach, California.

Tonight for May 2, 2015

The green flash image at the top of this post was taken by Jim Grant, our friend on Facebook. He captured it off the coast of Ocean Beach, California. He called it a mock mirage green flash.

You can see green flashes with the eye, when sky conditions are just right, if you are looking toward a very clear and very distant horizon. That’s why those who see green flashes most often see them over a sea horizon. You also must be looking just at sunset, at the last moment before the sun disappears below the horizon. And you have to be careful not to look too soon. Wait until just the thinnest rim of the sun appears above the horizon. If you look too soon, the light of the sunset will dazzle (or damage) your eyes, and you’ll miss your green flash chance that day.

Can you see a green flash? More tips, plus more pictures

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky planisphere today.

EarthSky Facebook friend Jim Grant caught this green flash on April 27, 2012 off the coast of San Diego.

Click here to expand image above

There are many different types of green flash. Some describe a streak or ray of the color green … like a green flame shooting up from the sunrise or sunset horizon. The most common green flash, which many people describe, is a flash of the color green seen when the sun is nearly entirely below the horizon.

Green flash image by Mike Baird. Used with permission.

You need a distant horizon to see any of these phenomena, and you need a distinct edge to the horizon. So these green flashes, streaks, and rays are often seen over the ocean – but you can see them over land, too, if your horizon is far enough away. Pollution or haze on the horizon will hide this instantaneous flash of the color green.

If you’re interested in green flashes, Andrew Young’s green flash page is great. He also has a page of links to pictures of green flashes taken by people from around the globe.

Here’s another good article about the green flash by Peter Michaud.

And here’s a rather subtle green flash video here. I had to watch it several times to convince myself I saw any green.

Bottom line: The green flash is legendary, and some people have told us they thought it was a myth, like a unicorn or a pot of gold at the end of a rainbow. But green flashes are very real. You need a distant and very clear horizon to see them at the last moment before the sun disappears below the horizon at sunset.

Help support EarthSky! Visit the EarthSky store for to see the great selection of educational tools and team gear we have to offer.