Moon Halos | Sophie Sills

It was a clear night in January. I was in Mexico with my family, looking up at the night sky. Suddenly, I noticed it: a defined ring of light around the full moon, unlike anything I’d ever seen before. Slightly in awe, I asked my sister if she saw it as well, and she indeed confirmed that she did. Initially, I expected that this was merely a strange natural phenomenon that I would likely not have the chance to experience again. But when I returned home, I saw it again maybe two or three times. Now, in an attempt to research interesting topics for today’s online, I stumbled across an article on natural phenomena, one of which being these peculiar “moon rings” I had long forgotten about. So, one thing led to another, and now thanks to further research, I can look up into the night sky and say that I know what these rings are and why we see them from Earth. So, without further ado, here is the story of Moon Halos.

Although Moon Halos seem as though they would be a surprising spectacle, they actually aren’t rare. These halos are caused by cirrus clouds, the wispy clouds that sit highest in the sky. As temperatures are very low at these higher altitudes, cirrus clouds are made up of hexagonal ice crystals (as opposed to water), which have the potential to refract light. When light passes through these crystals, it bends at a 22 degree angle, creating a circle, or halo around the moon with a 22 degree radius. Interestingly though, on any given night, each and every person sees their own rendition of the halo, depending on the way the light refractions make their way to our eyes.

Much like other types of interesting clouds, the cirrus clouds that cause Moon halos occur most frequently in the time before or during storms or inclement weather, which is why folklore and science alike mark these halos as indicators that a change in weather is to come. However, due to their unpredictability, Moon Halos have been spotted simply in cold temperatures or during periods of relatively normal weather as well, and can be commonly seen here in the U.S., in the moon’s fuller stages.

Halos are not unique to the moon, though. Although slightly difficult to spot, Solar Halos exist as well, and can be seen during daytime, especially in cooler temperatures or at extremely high latitudes. Halos are especially interesting to see in the daytime, as this is when their colors can be most easily seen. Solar Halos appear almost like a dull rainbow around the sun and can signify weather changes as well.

Unfortunately, due to a the lack of information on these Halos, this is where our lesson ends. So next time you look up at the sky and notice something peculiar, consider doing some research: it will likely be worth it, and may shed some light the on fact that an otherworldly-seeming phenomena is not all that rare to see if you take the time to look.