Listening to the audio of the featurette here (select the "closed-caption" quicktime video) the commentator pronounces the name of the moon Dione as "DEE-oh-nay". I've always thought of it as "DI-own", but I suppose I haven't heard anyone knowledgeable pronounce it. Does anyone have a sense as to what pronunciation is in common usage?

The following is from a Wikipedia discussion board:

Most sources -- astronomical, mythological, and dictionaries -- give the pronunciation as [dye-OH-nee], though a few, including some at JPL/NASA, have [DYE-uh-nee].

All three vowels are long (Dīōnē), so the stress should be on the o.

I've usually used Dee-OH-nee (which would give you Dee-oh-nay in some accents). Who was in the featurette BTW? I haven't seen it.

A lot of these different pronunciations come from adherence to different standards which have changed over time.
The ancient Greek pronunciation would have been, approximately, "dee-OH-nay", and the Latin version of this name would have had about the same pronunciation.
Due to language changes, the modern Greek pronunciation will be approximately "the-OH-nee".
Traditional English pronunciations of Greek and Latin names are largely based on the old academic pronunciation of Latin, which incorporates various sound-changes from medieval Latin, Old French, and changes that have taken place within English itself over the last six hundred years. In this particular case, those changes are not very striking.
Around 1400, literate Englishmen would have still said "dee-OH-nay". By 1600, it would have been "dee-OH-nee". In more recent times, the pronunciation has become "dye-OH-nee"; this last is probably, though not certainly, the pronunciation John Herschel had in mind when he proposed the name in 1847.
For English speakers I think both "dee-OH-nee" and "dye-OH-nee" are acceptable. To say "dee-OH-nay" is also acceptable, but suggests you're trying to impress by showing how conversant you are with ancient Greek pronunciation. I cannot think of any good justification for stressing the name on the first syllable. Other languages will, of course, have their own appropriate pronunciations, or even spellings.

I've also heard alternate prouniciations for Mimas, Tethys and Janus. Pronouncing the latter with a long "A" seems particularly unforgivable; it's a Latin name, and the "a" in Latin is always short.

But what do I know? I only learned a few years ago that I've apparently been pronouncing Deimos wrong for decades; the "ei" is pronounced like a long "I", not a long "E". *sigh*

By the way, Henry S.F. Cooper noted in one of his "New Yorker" reports on planetary exploration that some of the Voyager scientists pronounced Enceladus like "enchiladas". My personal favorite, however, is two reporters I know of who called Io "Ten".

I read all about the planets and the asteroids and the stars back when I was a wee lad... and back before I had a clue as to how Latin and Greek were pronounced.

I did my best, but for a long time, I horribly mis-pronounced most of the names when I read them. (I never had a lot of opportunities to speak them.)

So... I had a lot of interesting (and wrong) pronunciations in my head. Like EYE-oh (Io), en-sell-AH-dus (Enceladus), DYE-own (Dione), bet-el-GEEZ with a hard 'G' (Betelgeuse), and my favorite, oh-FIE-u-kus (Ophiuchus).

Even though I know better now, some habits die hard. I still have a hard time reading the name Io as "EE-oh." It'll always be "EYE-oh" to me...

-the other Doug

You should have heard me pronouncing the names of Goethe, Proust and Nietzsche when I first ran across them at age 10 in Arthur C. Clarke's "Profiles of the Future".

Yes and no. As I mentioned above, there are several ways to pronounce any of these names: in the classical Latin way, and in several later pronunciations of Latin used from medieval through modern times. In classical Latin, the correct pronunciation of Janus (some classicists would insist on "Ianus", though) would be YAH-noose. However, that's not necessarily the correct pronunciation in English!

In the Old French pronunciation of Latin, an initial y-sound (written i or j) came to be pronounced "dzh" (i.e. like English j; the modern French pronounciation of j as "zh" arose later). This pronunciation was taken over into English. So around 1400 the correct pronunciation would have been DZHAH-noose.

But later on, short a became lengthened in English when in the initial open syllable of a two-syllable word. By 1700 this lengthened "a" had become the sound English speakers know as "long a", i.e. the a in words like "famous" or "paper". This change affected not only English words, but the English pronunciation of Latin as well. Consequently, it is thoroughly correct to pronounce "Janus" as JAYNE-us (the change of the oo-sound to English short u -as in "us" or "hut"- is relatively recent).

In Latin, the original "a" in "Ianus" actually was long, but this has nothing to do with the traditional English pronunciation! A word with an etymologically short vowel in an open syllable that was the first of two syllables was also lengthened; the traditional pronunciations of words like calor and latus were KAY-lor, LATE-us, even though in Latin the "a" of both words is short.

Very recently -- since 1950, maybe, and perhaps influenced by an aversion to using the very English-sounding "long a" sound in Latin words -- some speakers, like Bruce, have taken to substituting an English "short a" (as in "tap" or "flat"). This yields pronunciations like DAT-uh or STRAT-um in place of traditional DATE-uh, STRAIT-um (i.e. data, stratum); and, I assume, JAN-us instead of JAYNE-us.

Given that language is changing constantly, there is no way to be doctrinaire about pronunciations. But until the last few decades, anyway, JAYNE-us was by far the predominant pronunciation among educated speakers of English, when using the name in an English context.



There is actually no correct pronunciation for this name! The spelling, which imitates that of ancient Greek, suggests a pronunciation of "DAY-moss" or "DAY-mose". (Modern Greek pronunciation would be approximately "THEE-mose"). But if pronounced in a Latinate way -- like most astronomical names of Greek origin -- it would be "DIME-us" -- but only because Greek "ei" was, for the most part, borrowed into Latin as long "i" (early pronunciation "ee", but Anglicized pronunciation "eye"). Some handbooks -- influenced, I suppose, but the spelling -- assert a pronunciation DEEM-us. I can think of no very good argument for that pronunciation, but it must have been common in some circles. I say "DAY-mose" (and likewise FOE-bose for Phobos), but only because the name-inventor (Asaph Hall, I assume) has gone to such obvious pains to make the names look Greek and not Latin.

Traditional Anglicized Latinate pronunciations of Mimas and Tethys are "MIME-us" (if you're touchy about saying "MIME-ass", anyway) and "TEETH-iss". I imagine that confusion with the classical, or neo-classical pronunciations, has made some people say "MEEM-us" and "TETH-iss".

And "EYE-oh" is the traditional English pronunciation of that name, so I wouldn't be too embarrassed about it.



There is of course no way of telling whether the second or third syllable from the end is stressed -- in words of this form -- without using a dictionary. It just happens that the "a" is etymologically short, and so it has to be (in Latinate pronunciation, anyway) "en-SELL-ah-dus". That syllable also bears the Greek accent, but that's coincidental.



There's no good rule for handling these medieval manglings of Arabic. One resource I have recommends "BET-ell-jow-ZEH" (though it allows "bettle jooze" and "beetle juice" as possibilities!). In Arabic, it was "yad al-jauza'", meaning "Hand of the Middle One" ("middle" perhaps referring to Orion's position on the celestial equator). The y (a line with two dots in Arabic) was misread by Europeans as b (a line with one dot).



Again, without a dictionary, you can't be expected to know the position of the stress. In this case, it happens to be on the first "u", because that is etymologically long (corresponding to Greek "ou"). That gives the pronunciation "off-ee-YEW-cuss".

I also came up with some God-awful pronunciations of moons, constellations and stars when I was a kid. Probably the worst one was my version of Phoebe: FOE-ebb.

This sort of thing is inevitable when you are the only person in town who is interested in astronomy. Since I grew up in small town Ontario, I'd have been better off learning how to pronounce the names of hockey players.

I called it Die-own too tfisher so don't feel too bad.

What has confused me recently is the fact that certain languages have their own spellings for many moons. I always thought that satellite names were similar to the names of species in that they were common across all languages. But instead I am confused for weeks as to what "Teti" is.

Did you have any trouble with "Giapeto" and "Giano"?

(The inner moons of Saturn (Saturno) have the Italian names Pan, Atlante, Prometeo, Pandora, Epimeteo, Giano, Mimas or Mimante, Encelado, Teti, Telesto, Calipso, Dione, Rea, Titano, Iperione, and Giapeto; Phoebe becomes "Febe". I don't know if there are official Italianizations for Daphnis, Methone, Pallene, Polydeuces, or Helene, but I imagine Dafni, Metone, Pallene, Polideuce, and Elene.)

Yep -- it took me forever to figure out that this "Go-erd-the" fellow people talked about was really that "GO-thee" person...

-the other Doug

Nope, got it now. But still, I was a little surprised that the spellings of satellite names are changed in various languages. I know, perhaps I shouldn't have been had I thought it over for more than three seconds, but still. Thanks, for the list though.