Lunar rainbow over southern Japan (Image: Creative Commons, courtesy of Mila Zinkova)

On yesterday’s TV news, we got a stunning view of the “lunar rainbow” phenomenon. I thought for a moment that that must be the proverbial “pot of gold” at the end of the rainbow. In fact, it looked like there were two pots of gold at each end…as seen in the photo below.


A rare lunar rainbow (a.k.a. moonbow, night rainbow, space rainbow) lights up the sky over Ishigakijima island, Okinawa Prefecture, captured on the 7th of January. (Image captured by the meteorological observatory camera and image provided by National Astronomical Observatory of Japan) In Japanese, it is called the Gekkou (月虹), so-called because it is a rainbow produced by moonlight, and as such it is usually harder to see. A larger photo can be viewed at this Okinawa Times page.

The phenomenon is explained in an UPI article “Rare moonbow photographed in Japan” thus:

“In the rare phenomenon, a ghostly multicolored arc is created by light reflected off the surface of the moon and always appears in the opposite part of the sky from the moon, experts said.

Small water droplets in Earth’s atmosphere refract the light from the moon, creating the lunar rainbow, also knows as a moonbow.

The moonbow was observed by the Ishigakijima Astronomical Observatory on Ishigakijima Island in Okinawa Prefecture, The Asahi Shimbun reported Thursday.

Moonbows occur with a combination of very dark skies, just before or after a full moon when it is brightest, and rain falling opposite the moon, scientists said.

While moonbows are often so faint they appear white to the human eye, the observatory’s camera was able to capture the multiple colors in it, they said.”


If watching the skies with the kids is your kind of thing, put a post-it! on this date May 21st, 2012 around 8 am. Because that’s when a solar eclipse will be happening … its trajectory will right overhead of Tokyo. It was mentioned on NHK TV news, and you may find more details of its trajectory and other information at these links:  Wiki:Solar_eclipse_of_May_20,_2012 and NASA’s page

By Aileen Kawagoe