Talk:Europa (moon)

Featured on Template:March 2 selected anniversaries (may be in HTML comment)

---

Contents

1 Continent Europe naming 2 Axial tilt 3 Data for Europa 4 Naming of the Galilean satellites 5 geysers 6 Pronunciation

Continent Europe naming

The continent 'Europe' was named after the word 'Ereb'. 'Ereb' means 'land of sun set' in ancient greek/latin.

Where does that come from? I thought the name of the continent had a mythological origin. Also, "ereb" isn't what you'd expect for either a Latin or a Greek word. --kwami 00:26, 11 Apr 2005 (UTC)

---

This article states:

 "It has an outer layer of water ice thought to be around 100 km 
 thick

then later says:

 "...based on this and on the calculated amount of heat generated 
 by Europa's tides it is predicted that the outer crust of solid 
 ice is approximately 10-30 km thick, which could mean that the 
 liquid ocean may be as much as 90 km deep underneath."

Am I correct in assuming that the first number refers to the thickness of the water AND the ice, combined? Not just the "water ice"?

I'm fairly certain that the first statement is referring to water ice as opposed to other ices, somewhat common in the outer solar system. But yes, it would include the liquid water as well. --Patteroast 22:02, 17 Apr 2004 (UTC)

Axial tilt

I noticed that this page does not have a value for Europa's Axial tilt...Does anyone know this value?

Data for Europa

I removed the paragraph below because it reiterates the article, or is trivially calculated from data in the table. None of the other Galilean moons have a similar paragraph.

Data for Europa:

• Surface Gravity (Earth = 1): 0.135
• Orbit Speed: 13.74 km/s
• Escape velocity: 2.02 km/s
• Surface Composition: Water Ice

—Herbee 16:45, 15 Jun 2004 (UTC)

In case you were curious why that was there, originally most of the planets and moons had a list of facts similar to this before the Wikiproject to give them all a uniform table started. I guess this just got missed during cleanup. :) Bryan 00:55, 16 Jun 2004 (UTC)

Naming of the Galilean satellites

 "Although the name "Europa" was suggested by Simon Marius soon
  after its discovery, this name and the names of the other Galilean
  satellites curiously fell into disfavor for a considerable time..."

I've heard speculations that Marius invented the names just to annoy Galileo. These names probably weren't considered appropriate as they were named after the lovers of Zeus -- especially with the case of Ganymede, who was male. --Jyril 23:07, Feb 27, 2005 (UTC)

geysers

shouldn't the geysers be mentioned? kwami 12:30, 2005 May 6 (UTC)

I don't think there are geysers on Europa. You may be thinking of Enceladus or Triton. The Singing Badger 19:16, 10 May 2005 (UTC)

Yup, eruptions off the limb of Europa were imaged by Voyager, and recognized some weeks after the flyby. Not as numerous as the Ionian eruptions, of course. I don't recall anything similar from the Galileo mission. kwami 10:14, 2005 May 30 (UTC)

Could you verify that claim? As far as I know, geysers on Europa are still hypothetical. Galileo orbiter tried to detect them, but was unable to find any. Galileo images show very smooth plains between the cracks suggesting that there may have been active cryovolcanism recently. But no active geysers/cryovolcanos have been detected.--Jyril 13:47, May 30, 2005 (UTC)

I've been unable to find anything online. I remember the interpretation of the plumes on Europa's limb was rather speculative. Perhaps it turned out to be something else, which wasn't news, so there was no followup to the story? I'll keep looking, or try writing someone at JPL. kwami 17:21, 2005 May 30 (UTC)

Heard back from the NSSDC:

It is believed that the "plume" seen on Europa was actually an artifact of the Voyager vidicon system. A search for plumes using Galileo found none, so the question of geysers on Europa is still open. —kwami 03:45, 2005 Jun 17 (UTC)

Pronunciation

Instead of the pseudo-phonetic transcription, I replaced it with what seems to me as a reasonable phonemic transcription and a a sound file of my own Americanized English. I've intentionally avoided using any special IPA characters for stress and vowel length since they have a tendency to look very odd in some browsers. Change this if you want, but try to at least keep it phonemic, or we might get more disputes over which is to be conidered correct. Don't take the sound file as an excuse to start bickering over the merits of various varieties of English. It's not supposed to be canon, and anyone listening to the sound file will at once know how to pronounce it in their own dialect/accent.

Peter ^Isotalo 13:13, May 29, 2005 (UTC)

We have the same cross-dialectical spelling pronunciation for all of the moons of the solar system and most of the first thousand asteroids. Add the IPA if you like, but don't delete the other. kwami 19:36, 2005 May 29 (UTC)

Oh, for crying out loud... Did you even notice that it wasn't accepted too well by non-native speakers? I was trying to avoid that.

Peter ^Isotalo 09:41, Jun 5, 2005 (UTC)

If you put in an IPA pronunciation, people start complaining about dialect chauvinism. (Maybe not a problem with Europa, but certainly a problem elsewhere.) Plus, half the English-speaking world doesn't have a clue what the IPA even is, let alone are able to use it. Rather than learn, they'll just ignore it. If it's useless for half the population, and contested by the other half, why should we try to make it the sole representation of English pronunciation? If you can figure out a way to transcribe into the IPA so that it represents all major English dialects, that would still only address half the problem. (I'm missing too many low vowels to attempt it.) Ideally we would have both. kwami 09:59, 2005 Jun 5 (UTC)

Pseudo-phonetic orthographic transcription seems like something people could fight about for ages as far as I can tell. At least IPA is as close to a neutral standard as one can get, and it is certainly not something exclusisve to English speakers. Now, if you actually take some time and read the transcription you'll notice that I deliberatly made it phonemic instead of phonetic. In other words, it's perfectly dialect-neutral.

Peter ^Isotalo 22:56, Jun 6, 2005 (UTC)

Yes, but it's only dialect-neutral for Europa. Your approach won't work for all the moons, because English dialects differ in their phonemic inventories, unless you specify that there is not a one-to-one correspondance between sound and symbol. Then people will argue with you about that, claiming that the IPA is supposed to be one-to-one.

We've also had very few problems with the spelling pronuciations. (A couple people didn't like the digraphs ah and oh, so we changed them to aa and oe, but that's it.) I don't see any problem with having both. At least now you have something to work with, which wasn't the case when I started. Oh, by the way, the spelling pronunciation is also phonemic, not phonetic (pseudo or otherwise). kwami 23:37, 2005 Jun 6 (UTC)