Did you know that our moon can look different at different latitudes? Earlier in this month I saw my first Cheshire moon and it was spectacular. I wanted to learn more about it, so down the rabbit hole I went (and yes, pun intended since the ‘Cheshire’ name is a nod to the smile of the cat in Alice in Wonderland) …
The Wet Moon
For six months, the path of the moon goes south of the stars, which changes its appearance on the horizon. In the summertime, the lunar path appears closer to the southern horizon in the northern hemisphere. This makes the moon look like it’s lower in the sky. This happens because the earth changes its tilt in relation to the plane in which the moon orbits.
In the wintertime, this process reverses and the moon’s appearance looks higher in the night sky. The cusps of the crescent moon point upward, and that’s what’s referred to as the Wet moon, because it looks as if the moon may be holding water, like a boat. The shape also resembles a smile, so that’s where the Cheshire nickname derives from—that cat had a mischievous grin.
Moon Mythology
Hawaiian folklore is to credit for the Wet moon reference (and its counterpart, the Dry moon, which points to the side).
In the wintertime, when the moon is most visible in this way, in their culture, it is known as the period of Kaelo, who is the water bearer. He makes the moon, which they refer to as the “dripping wet moon.” The mythical bowl empties as the moon’s cycle continues and the shape changes to essentially ‘pour out’ the water from said bowl in the summer … which produces the Dry moon.
Moon Math
The cool thing about the lunar cycles and its different stages of visibility is that it enables you to learn about your own whereabouts. If you observe the phases throughout the month, you should theoretically be able to disseminate direction. More precisely, celestial navigation has historically been used at sea like a compass to help sailors orient themselves in ocean waters.
For those who want to dive deeper, a fascinating, detailed exploration of all the ways the moon can be used to calculate location can be found at the Astrolabe Sailing blog.
Water on the Moon
While the Cheshire moon is commonly referred to as the wet moon simply due to its shape, NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA)—a modified jetliner with a precise 106-inch diameter telescope—announced just last year that they had discovered actual water (!) on the ‘sunlit surface of the moon.’ You can view footage of this finding here.
The detection happened in the Clavius Crater in the moon’s southern hemisphere. The amount was relative to a ‘Tall’ size Starbucks drink—around 12 oz. to be exact.
The findings came as somewhat of a surprise, as when the astronauts on the Apollo mission visited the moon in 1969, they thought the surface to be completely dry. More recent missions since the early 2000s indicated the presence of ice near the poles and evidence of hydration in warmer areas, but until SOFIA’s confirmation, it wasn’t known if water was there.
There are multiple theories as to how this water is getting to the moon. One possibility is that micrometeorites produce rain that deposits water on the lunar surface. Another idea is that the sun’s solar wind could be delivering hydrogen that causes a chemical reaction with minerals that transform into water.
NASA will use SOFIA in follow-up flights to search for additional surface areas that may contain water. The scientists hope that the findings will help create the first water resource maps of the moon to aid in future space exploration by humans.
What’s the most amazing moon viewing you’ve ever had? Share your experience in the comments section (and be sure to let us know what location you were in when you had it).
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Photo credits: Moon, jrrivers1/Pixabay; Cheshire Cat, tookapic/Pixabay
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