With 14 below on the thermometer this morning I don’t think Full Worm Moon quite fits as a description for tonight’s full moon. How about the Sap Moon, named for the time when sap begins to run again in maple trees? No, a little too early for that. These traditional Native American moon names obviously applied to other more clement regions of the country where March really does mean the start of spring.
More like the Full Stubborn Moon in my town. Yet the signs of spring are unmistakable. Longer days, shorter nights, a steeper slant to the sunlight. Spring stars are pushing up in the east as well – scintillatious Arcturus is up by 9:30 in the northeast, followed by Virgo’s Spica an hour or so later.
We enjoy watching these seasonal changes. They help us get out of bed and renew that enjoyable sense of anticipation at what’s around the next corner. Constant motion. We’ve been told everything’s in continual movement. If you could shrink down to size of a bacterium you’d never be able to sit still. At that level, you’d feel the pinging of millions of molecules called Brownian motion. Getting up and walking to another room you’d be pelted by a hail of molecular snowballs.
Lucky then that humans are big enough to escape such atomic beatings. But the incredible variety of motions still can throw us off. The stars rise and set, reflecting the rotation of our planet, constellations shift westward with the seasons as Earth orbits the Sun, the moon and planets march east, contrary to the motion of the stars.
When you watch the moon rise tonight, be aware that as the Earth’s rotation brings it into view, the moon’s orbital movement wants to drag it back down to the horizon. Reminds me of trying to get a teenager out of bed. The Earth wins of course because the moon is far enough away that its apparent motion to the east amounts to only 1/2° or one moon diameter per hour. Meanwhile, Earth’s west-to-east rotation uproots our satellite and whips it to the west 30 times faster. Sorry moon, you lose.
It’s all illusion of course. The moon’s doing most of the moving. Its nightly rising in the east and setting in the west are nothing more than a reflection of our planet’s spin. Fake motion. By the way, those little 1/2 degrees add up – every 24 hours the moon moves more than a fist to the east.
While the moon may appear to lose to Earth, this isn’t true with Mars’ moon Phobos, which lies so close to the planet that it takes just 7 1/2 hours to orbit it. Moving eastward at 45° per hour (90 times faster than the moon), Phobos rises in the west and sets in the east after only 4 hours. Four hours later’ it’s back again at the western horizon ready for another trip across the night sky. Mars’ rotation rate of 24 hours 37 minutes just can’t keep up with this insanely fast moon.
While I’d be the first to purchase a cheap ticket to Mars just to see crazy Phobos, I rather like the unhurried and deliberate moon that rises over Earth. Time to watch moonlight transform the landscape and help us slow down a little after a busy day.