Sky Tonight—May 12, How to see the green flash

Courtesy of EarthSky A Clear Voice for Science Visit EarthSky at www.EarthSky.org The image today is a classic image of a detached green flash, seen at sunset. You can see green flashes with the eye, sometimes, if you are looking toward a very clear horizon. You 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, ... Full Story