We’ve had a lot of clouds around here lately until the last couple nights, when the moon finally broke through the overcast It cheered me (and maybe the dog, too) to see it shine again on our nightly walks.
Monday’ the Full Hunter’s Moon but for almost a week we’ve been watching the waxing gibbous moon, that curiously-named phase between half (first quarter phase) and full. The name gibbous comes from the Latin ‘gibbus’ meaning humped or hunched. And if you think about it, a gibbous moon does bear a passing resemble to a camel’s hump – circular on one side and slightly flattened but still round on the other.
Waning gibbous moon begins after full moon and lasts till just before last quarter, when the moon is half again. If you add up all the nights the moon is gibbous it comes to almost two weeks, making it the most commonly visible moon phase.
Two weeks is also about the same number of nights the moon’s a crescent, but crescents set early and rise late. They’re also closer to the sun in the sky and get missed because of glare and low altitude.
Not so with gibbous. Much more of the moon is illuminated by sunlight and it’s already up in the southeastern sky well before the sun sets. By early evening, a gibbous moon burns brightly against the deepening blue of twilight.
When considering a moonlight ski in mid-winter, we might imagine full moon’s the best time. While it’s true full moon is brightest, it may not always be ideal. You have to wait until later in the evening when the moon’s high enough for its light to penetrate the forest to ski safely. A gibbous moon on the other hand hangs like a lantern high in the south early in the evening. What it might lack in brightness it makes up for in altitude.
The gibbous moons from now through mid-winter will always be high up in the sky during early evening hours for northern hemisphere sky watchers. Consider this an invitation to to bust a hump and experience the joys of gibbousness.