Moonbow Observed from the Canary Islands

March 18, 2019

MoonBow -Lunar RainBow - Arcoiris de Luna- Eclipse de Luna 21-01-2019 (1)

March 2019 Viewer's ChoicePhotographer: Jose Fernández Arozena
Summary Authors: Jose Fernández Arozena; Jim Foster

The photo of the graceful rainbow shown above was taken at night. I captured it a little before sunrise, from El Paso, La Palma, Canary Islands of Spain, while observing the total lunar eclipse of January 21, 2019 -- the camera was facing east. My friends, Leopoldo Martin and Sergio Armas, and I noticed this bow  opposite of the Moon's position in the sky, between some clouds, as the eclipse was ending. The bow is, of course, illuminated by the full Moon, which had just reappeared from the Earth's umbra.

Lunar rainbows or moonbows are rarely seen because the light from the Moon, even when full, is quite feeble compared to sunlight. Moonbows look rather pale compared to their daytime cousins since their light isn't sufficiently bright to activate the cone receptors in our eyes. As is the case with all rainbows, the source of illumination, whether from the Sun or Moon, must be less than 42 degrees above the horizon for a bow to appear. If the forecast where you live calls for showers tonight or tomorrow tonight (the Moon will be full or nearly so) take a look to see if you can detect a moonbow.

Photo Details: Camera: SONY ILCA-68; Software: Adobe Photoshop CS6 (Windows); Exposure Time: 1.600s; Aperture: ƒ/3.2; ISO equivalent: 2000; Focal Length (35mm): 16; tripod and remote trigger.