q & a

Here are some of the questions which visitors to Inconstant Moon have asked. They have been divided into six sections...

movement: the moon's orbit and phases
physical: form, characteristics and geology
phenomena: unusual lunar events
observation: what can be seen... and what can't
terminology: naming of the moon, phases and features
miscellaneous: anything not covered avove

If you cannot find the answer to your question, go ahead and ask it!

naming the seas

q: What exactly does the Sea of Tranquility mean? (Alexis Foltz, Des Moines, Iowa)
a: Hundreds of years ago, when people first looked at the Moon through telescopes, they noticed that the dark areas were very smooth with almost no mountains or craters. Some people thought they were water, and although we now know that they are actually younger, less battered areas of rock, the labels like sea, ocean, bay etc. are still used.

It was a priest named Riccioli who named most of the features on the Moon. He named the craters after famous people like Tycho and Copernicus. The seas were named after phenomena and states of mind. Most of those on the west side of the Moon relate to wet weather: Sea of Rains, Ocean of Storms, Bay of Dew. On the east side we find happier names, like the Sea of Serenity and the Sea of Tranquility, which both mean peacefulness.

Astronomers usually use Latin names, so Sea of Tranquility becomes Mare Tranquillitatis.

quarter moon

q: How come the quarter moon isn't called a half moon, because that is the shape?
a: The terms first quarter and last quarter refer not to the Moon's shape but to the points in time within the lunar month. If this principle were extended, the full moon could be called either the second quarter or even the half moon!

full moon names

q: Harvest Moon, Hunter's Moon, Planter's Moon... are there other full moons that have specific names? (Jay, Seattle)
a: Full Moons occur roughly once each month. The traditional English names for them, and the native American ones, tend to reflect natural and agricultural themes for the months in which they fall.

MonthEnglish nameNative American names
JanuaryMoon After YuleWolf Moon, Old Moon, Great Spirit Moon
FebruaryWolf MoonSnow Moon, Hunger Moon, Sucker Spawning Moon
MarchLenten MoonSap Moon, Worm Moon, Moon of the Crust on the Snow
AprilEgg MoonSeed Moon, Pink Moon, Sprouting Grass Moon, Sap Running Moon
MayMilk MoonFlower Moon, Corn Planting Moon, Budding Moon
JuneFlower MoonStrawberry Moon, Rose Moon, Hot Moon
JulyHay MoonBuck Moon, Thunder Moon, Middle of the Summer Moon
AugustGrain MoonSturgeon Moon, Green Corn Moon, Rice-Making Moon
SeptemberFruit MoonCorn Moon, Harvest Moon, Leaves Turning Moon
OctoberHarvest MoonRaven Moon, Hunters Moon, Dying Grass Moon, Falling Leaves Moon
NovemberHunter's MoonBeaver Moon, Frost Moon, Hunter Moon, Ice Flowing Moon
DecemberMoon Before YuleCold Moon, Long Nights Moon, Little Spirit Moon

disseminating moon

q: Why do you call both the waxing and waning phases between the first quarter moon to the last quarter moon a "Gibbous Moon"? I was taught that the first quarter to full moon phase was the Gibbous Moon, but, that the full moon to last quarter phase was the Disseminating Moon. (Jann, Boring, Oregon - yes, it's really called that)
a: The term 'gibbous', like 'crescent', simply describes the shape of the moon - specifically when it is more than a half disc but less than a full disc. Amongst astronomers (those who study the quantitative science of the stars and planets) the gibbous phases before and after full are distinguished simply by the prefix "waxing" or "waning". The same also applies to the crescent phases.
Some astrologers (those who follow the qualitative subject of the influence of the stars on human affairs) use the term "disseminating" for waning gibbous and "balsamic" for waning crescent.

naming the moon

q: The moons that belong to the planets in our solar system all have names. What is the name of the earth's moon? (Linda)
a: For most of human history the Moon has been only known object of its kind, like the ground and the sky. Nobody needed to distinguish it from others, so although it has been associated with many deities (such as the Greek Selene, Artemis and Hecate and the Roman Diana) it was never really given a name. Even when satellites were found around other planets, starting with Galileo's discovery of the four largest moons of Jupiter, names were only devised for the new objects. Undoubtedly if Earth had more than one moon, they would have had names of their own. Some people use the Latin words as names for the Moon (Luna), the Sun (Sol) and the Earth (Terra).