Today, when we look at the heavens, we tend to focus on faraway galaxies, stars, planets, black holes, and even a comet or two. But for much of human history, the earth’s moon reigned supreme in both our cosmology and collective imagination.

The word moon derives from the Old English word mona. There exist similar words referring to the moon in Old Frisian, mene, (a Germanic language spoken in the 6th to 8th centuries, A.D.), Middle Dutch (mane), Old Saxon (mano), as well as Old Icelandic and Danish. By the 15th century, English-speaking people began spelling it in the more familiar way as moon or, occasionally, adding a silent e (moone).

The Latin word for moon, of course, is Luna. Luna was the Roman incarnation of Selene, the Greek goddess personifying the moon. (The word Selene likely comes from a Greek root selas, for brightness). The adjective lunar is still used today when referring to the activities and features of the moon. But in Antiquity, lunar was also often employed in reference to both a woman’s menstrual cycle and to insanity, (i.e., lunacy, lunatic).

While only a quarter of the size of the Earth, the moon rotates on its own axis every 28 days. Charting its waxing and waning progression from new moon to full moon, our predecessors were able to develop the first monthly calendars. Even the word month is likely derived from the word moon and an Indo-European word, mê, which means to measure. Most modern-day lunar calendars are actually lunisolar and have intercalary months added to prevent too much shift of seasons, such as the Hebrew, Chinese, Hindu calendars. The Islamic calendar, on the other hand, is a purely lunar calendar.

The gravitational and centrifugal forces of the moon, Earth and the Sun influence the daily rise and fall of our planet’s oceans, some three feet worldwide, a critically important power those living on coastal waters or venturing the high seas.

Its striking surface of dark areas (the lunar seas) and the lighter highlands have long inspired claims of a "man in the moon." With only a bit of imagination, it is easy to visualize a man’s face, formed by the disc of the full moon or as a profile formed by the crescent moon. Others have insisted they can see a man leaning on a fork or carrying a bundle of sticks, a man with a dog and a thorn bush, and even a rabbit standing on its hind legs.

Biblical lore once held that this was a man caught gathering sticks on the Sabbath and sentenced by God to death by stoning (Book of Numbers, 15: 32-6). Roman legend posited it was an exiled sheep thief. The Italian poet Dante claimed this man to be Cain the Wanderer who was forever doomed to circle the earth in his masterpiece The Inferno. We also find references to this mythical figure in the works of Chaucer, Shakespeare, and many others.

But the man in the moon’s most prominent literary appearance was in a book by the English bishop Francis Godwin (1562-1633). Published posthumously in 1638, and under the pseudonym of Domingo Gonsales, The Man in the Moone describes both a science fiction-style voyage to the Moon and a popular account of Copernican astronomy.

Which brings us to the old saying that the moon is composed of green cheese. Never a bona fide scientific theory, it actually was a popular proverb that found its way onto the pages of 16th and 17th century English literature. It was a metaphor for credulity and refers to the simpleton who sees a reflection of the moon in the water and mistakes it for a round wheel of new or un-aged, hence green, cheese.