“Orbit”: Of the earth, out of this world

John Glenn, the first American to orbit Earth, left Earth yesterday at the age of 95. In his honor, let’s gaze at orbit – a word whose origin turns out to be much more down to earth.

Leaving a mark

As part of Project Mercury, John Glenn orbited Earth three times aboard the Friendship 7 in 1962. But almost 600 years earlier, the word orbit wasn’t even a verb. It didn’t even refer to space, in fact.

When orbit entered English’s lexical orbit in the late 1300s, it named the “eye socket.” The word came from the French orbite, in turn from the Medieval Latin orbita, which named the same anatomical structure. This is why doctors use orbital to refer to the eye socket.

But the etymology of orbit gets yet earthier: The older meaning of orbita in Latin was a “track or rut made by a wheel in the ground.” This orbita, speaking of John Glenn, could also refer to leaving an “impression” or “mark.” How do we get from our eyes on the ground and in our heads to our eyes in the heavens?

Not rocket science. Just metaphor.

In orbiting the Earth, John Glenn truly left his mark. The original meaning of orbit in Latin was a “track made by a wheel in the ground.” Image by Vasant Dave, courtesy of freeimages.com.

“Circular” logic?

Latin’s orbita traces back to another noun, orbis, which denoted many “circular” objects: rings, disks, spheres, globes. Periods and cycles also have a circularity, and orbis named them, too – as it did, even way back in its original Latin, the path a heavenly body took across the sky and, yes, the eye socket. (Heavenly bodies were thought to encircle Earth, and eye sockets are a spherical encasement of the eyeball.) The deeper root of orbis is unknown.

So, when English developed its astronomical sense of orbit in the mid-1600s, it borrowed the word orbit again, this time straight from Latin. There are some important differences, though. For most Ancient Romans, celestial orbis and orbita referred to the circuit of planets, moons, suns, and stars as they revolved around Earth, while the English orbit has come to name the elliptical path an astronomical body takes around a more massive one as the result of gravity.

Out of this world

The Oxford English Dictionary attests orbit as a verb in 1946, and the expressions in orbit and out of orbit about a century before. And “out of orbit” is what exorbitant literally means.

More precisely, exorbitant derives from the Latin exorbitāre, “to go off track,” joining ex- (“out of”) with that original, “track” sense of orbita. The Romans used exorbitāre in legal contexts, referring to some action that went beyond the scope of the law. English adopted this meaning, too, in the 1400s, but over the following centuries, exorbitant designated behaviors that deviated from the norm, hence “excessive.”

John Glenn definitely exceeded norms, but only in some of the most impressive, inspiring, and heroic ways the United States has ever witnessed. He was a veteran of World War II and the Korean War. He was a US Senator, representing Ohio. At aged 77, he was the oldest person to go into space. He was a loyal husband of 73 years. And he was humble, lifelong supporter of science, wonder, and curiosity.

Glenn’s orbit was, in so many ways, out of this world.

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In a “galaxy”… so, so close to home

A long time ago, in a galaxy far, far away…

From its opening lines to its ticket lines, Star Wars,  whose latest episode, The Force Awakens, opened this week, is as epic as its interstellar setting.  But the etymology of this galaxy, it turns out, is so, so close to home.

Not just any old trip to the store. "Galaxy." Doodle by me.
Not just any old trip to the store. “Galaxy.” Doodle by me.


English first gazes at the word galaxy, so to speak, late in the 1300s. It first named the Milky Way. Several centuries later, it was referring to other such star systems, whose existence Edwin Hubble only officially verified in the 1920s.

Galaxy derives from the Latin galaxias. It may have entered English either directly from Latin or through a French form of the word, galaxie. Latin borrowed its word from Greek’s γαλαξίας (galaxias)short for γαλαξίας κύκλος (galaxias kyklos), which means “milky circle.” And at the center of this galaxias is no black hole: it’s γάλα (gála), “milk.” (The base is γαλακτ-, or galakt-.)

Milky ways 

Have you ever looked up a clear night sky and marveled at that streaming band of stars glowing white overhead? You’re beholding the Milky Way, the galaxy we call home. Indeed, as galaxy‘s etymology has already suggested, the Milky Way takes its name from its milky-white appearance. Chaucer himself notes this a long time ago in his oft-quoted “House of Fame”:

Se yonder, loo, the Galoxie,
Whiche men clepeth the melky weye,
For hit ys white…

This poetry of Milky Way was indeed inspired: the English name calques the Latin via lactea, a translation of the Greek galaxias kyklos, as we saw before.


Now, fix your etymological telescope on the Latin lactea and Greek galaxias. Do you see anything in common? Gaze at lact- and –lax- and you might see that the words share an orbit. (The basic Latin noun for “milk” is lac, source of lactic, lactate, latte, and even lettuce, whose juice is milky, apparently.)

For these Latin and Greek cognates, Indo-Europeanists propose a root *g(a)lag- or *g(a)lakt-, “milk.” But, interestingly, the American Heritage Dictionary of Indo-European Roots notes that “no common Indo-European root for milk can be reconstructed.” This is little curious, perhaps, given that scholars can construct a common root for, say, cow. Germanic words, such as English’s milk, suckle a different root: *melg-, which refers to “rubbing off,” an action for obtaining milk, I suppose.

The universe is home to hundreds of billions of galaxies, each of which holds hundred of billions of stars. And our word for these incomprehensibly huge, imponderably numerous phenomena derives from something so mundane, so ordinary: “milk.” Now I think that’s epic.

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Well over three billion miles from home, NASA’s New Horizons spacecraft has been sending back a treasure trove of images and information in its historic flyby of the dwarf planet Pluto. A treasure trove indeed, if we look to the etymology of Pluto.

Trans-Neputnian. "Gem." Ballpoint on lined paper. Doodle by @andrescalo.
Trans-Neputnian. “Gem.” Ballpoint on lined paper. Doodle by @andrescalo.

Of gods and dogs

American astronomer Clyde Tombaugh discovered Pluto at the Lowell Observatory in Flagstaff, Arizona in February 1930. With the discovery a sensation worldwide, the observatory took suggestions for the new celestial body’s name. A young student of classical mythology captivated by the new finding, 11-year-old Venetia Burney in Oxford, England suggested the name Pluto after the Greek god of the underworld. Her grandfather, a former Oxford librarian, passed her suggestion along to an astronomy professor at the university, who then cabled it the United States. In March, the name won the observatory’s vote, so it goes, as the god Pluto is concealed deep in his underworld just as the planet hides deep in the solar system. Additionally, Pluto’s first two letters nod to the observatory’s founder’s initials, Percival Lowell.

Walt Disney’s debuted his Pluto in 1931’s Moose Hunt. We don’t fully know the origin of Mickey’s dog’s name, but many suggest that Disney was inspired by the Pluto-mania of the day. Plutomania, or “the obsession with wealth,” is a rather different craze.

The root of all Pluto

In Greek mythology, Pluto (ΠλούτωνPloutōn) is an alternate name and identity for Hades, god of the underworld. He was associated – and confused – with Ploutos (Πλοῦτος), the Greek god of wealth, a domain Pluto himself was also known to rule over. See, riches like silver and gold come from Pluto’s territory: under the earth. Further, Pluto’s wife, Demeter, the goddess of the harvest, brought with her other treasures of the earth – grain – when she seasonally emerged from the underworld.

Pluto passed from Greek to Latin, entering into English as early as 1330 to refer to the Roman figuration of this god.

Greek has πλοῦτος (ploutos), meaning “wealth” and “riches.” The sense of ploutos, then, may originally been “overflowing,” as the American Heritage Dictionary of Proto-Indo-European Roots posits. Greek lexicographers Liddell and Scott connect ploutos to a verb πίμπλημι (pimplēmi), “to fill full.” The OED proposes a connection to πλεῖν, “to swim” or “to float.” These forms point our probe towards that Pluto of etymology, Proto-Indo-European, with an ultimate root *pleu, “to flow.” This root also yields English’s flow and flood – and fly, as in that very flyby of Pluto, if an etymology was ever to orbit itself. Via Latin, pluvial, “relating to rain,” is also so descended.

Lexicographer Eric Partridge suggests polus (πολύς), “many” or “much,” source of English’s prefix poly-. This is related to a Proto-Indo-European root that gives English full.

Of gods and men

News Horizons is the first flyby of Pluto, which is so incomprehensibly far away. Its images and information have certainly enriched our understanding of this dwarf planet, its moons, and its neck of the solar system. But what’s more, it has enriched our sense of what is possible, bestowing on professional astronomers and dreamy stargazers alike the riches of perspective: how immense the feats of man’s imagination, how tiny our place in the universe. If only that sense of wonder is what governed us under a plutocracy.


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