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Archive 5Archive 9Archive 10Archive 11Archive 12Archive 13Archive 15

Are Artificial Objects on Moon Visible from Earth?

I had this discussion the other day, one of the discussers proposed that the Lunar Rover was visible from Earth with a consumer-grade (Questar?) telescope. Are any man-made objects, left on the Moon, visible from Earth? Can anyone report a first-person sighting? With what equipment?

Grateful for any comments. Rainbow-five (talk) 22:06, 22 March 2009 (UTC)

One reason that the man never walked on the Moon advocates still sometimes sway the unwary is that there are still no telescopes that have been able to resolve the objects left on the Moon. And when I ask these "unbelievers" what will happen to their argument when such a high-resolution telescope becomes available and finds all these artifacts, I'm told that it won't really matter, because those objects could have just as easily been placed there by robotic landers. (Robotics just wasn't that far along back then.) But that's another story. Even the Hubble, which can "see" galaxies billions of light years away, is not able to resolve artifacts on the Moon. If I remember correctly, the best telescopes can resolve down to 5 arcseconds. Since the Moon is about 1800 arcseconds, and its diameter is about 3,475 km, this comes out to a resolution of roughly 9.7 km or 6 miles. If I have figured correctly, an object on the Moon, then, must be no smaller than 9.7 km wide to be able to be resolved by our best telescopes.  .`^) Painediss`cuss (^`.  06:46, 25 March 2009 (UTC)
Hubble has a resolution of about 0.1 arcsecond. That means 200 meters on the moon. Not good enough. Rracecarr (talk) 14:51, 25 March 2009 (UTC)

David Bowie

Why doesn't this article mention him? —Preceding unsigned comment added by 98.114.191.206 (talk) 01:05, 26 March 2009 (UTC)

Big Numbers and No-Break ( ) Spaces

I occasionally come across numbers over 999 that use a no-break space rather than a comma to separate the thousands, as in 1 000 (actually appears as 1 000 in an article) rather than 1,000. In an article such as this one, where mostly commas are used to separate the thousands, I'm tempted to replace the no-break spaces with commas in each case for the sake of consistency. It occurred to me, though, that the no-break space might keep the number from breaking in two if it falls at the end of a line. My assumption was that the Wiki software does not have the ability to sense the difference between a comma followed by a number and a comma followed by a (normal) space. So I tested this, and the software does have this ability. Whenever a comma is followed by a number, it behaves in the same manner as a no-break space. Therefore I will remove the no-break spaces and replace them with commas when consistency-within-an-article demands.  .`^) Painediss`cuss (^`.  03:34, 3 April 2009 (UTC)

Eclipses section

The final paragraph reads:

"The most recent lunar eclipse was on February 20, 2008. It was a total eclipse. The entire event was visible from South America and most of North America (on Feb. 20), as well as Western Europe, Africa, and western Asia (on Feb. 21). The most recent solar eclipse took place on September 11, 2007, visible from southern South America and parts of Antarctica. The last total solar eclipse, on August 1, 2008, had a path of totality beginning in northern Canada and passed through Russia and China."

  1. Is it wise to include "recent" occurrences of such things in Wikipedia? Is someone always "on top" of such things so as to change the dates when a new recent occurrence occurs?
  2. The last two sentences are unclear. Was the most recent Solar eclipse in 2007? or in 2008?
  3. And a minor grammar thing: "beginning" and "passed" are incompatible. Should read, ". . . beginning in northern Canada and passing through Russia . . .", or ". . . that began in northern Canada and passed through Russia . . .".

 .`^) Painediss`cuss (^`.  00:38, 5 April 2009 (UTC)

Normally, I'd say that, given it is a featured article, and the Moon (sort of the main point of eclipses), it's likely people will be on top of it. However, briefly skimming solar eclipses and lunar eclipses seems to indicate that the dates here are, in fact, wrong, and need to be corrected, if not removed entirely. Corrected grammar. ~ Amory (talk) 03:50, 23 April 2009 (UTC)

Exploration section

"36 years, 112 days have now passed since Eugene Cernan and Harrison Schmitt, as part of the mission Apollo 17, left the surface of the Moon on December 14, 1972 (Cernan being the last to enter the LM) and no one has set foot on it since." (the 36yrs, 112dys is as of 01:34, 5 April 2009 (UTC))

This is impressive. Somebody who (like me) thinks that it's been far too long since the last manned exploration of the Moon actually devised a bot to emphasize the point? Wow!  .`^) Painediss`cuss (^`.  01:34, 5 April 2009 (UTC)

The JAXA SELENE Earthrise link in the External links section is broken as of this date. I found another link to the Earthrise movie and replaced the broken link. In case the old link is only broken temporarily, I am preserving it with a comment on the article page, and also here...

 .`^) Painediss`cuss (^`.  04:49, 5 April 2009 (UTC)

  • PS: I considered adding a note about libration, but that might be too much.

Minor edit to the "Two Sides of the Moon" section

To remove the redundant "the" and the unnecessary "that", please replace the first sentence in this section with: "The Moon is in synchronous rotation, which means it rotates about its axis in about the same time it takes to orbit the Earth."
Thanks
Apachegila (talk) 10:35, 19 April 2009 (UTC)

Done. Vsmith (talk) 12:21, 19 April 2009 (UTC)

Number of Moons

According to QI Earth has five natural satellites, not one - as according to the article. —Preceding unsigned comment added by Greggydude (talkcontribs) 20:01, 22 April 2009 (UTC)


The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.
Consensus reached: article is fine where it is. Awickert (talk) 03:06, 31 May 2009 (UTC)

Should the title be "Moon" or "Earth's Moon"

see also: Talk:Sun#Should the title be "Sun" or "Earth's Sun"

Should the title be "Moon" or "Earth's Moon". I prefer Earth's Moon to make it clear that we are not talking about Moons in general. You could argue that "Moon" is clear enough, but why not make it clearer, you could argue that "Earth's Moon" looks weird, but so what, and it would be easier to make moon a disambiguation page. —Preceding unsigned comment added by Emmette Hernandez Coleman (talkcontribs) 03:11, 26 April 2009 (UTC)

Anyone with an opinion of argument about this, please post it.--Emmette Hernandez Coleman (talk) 14:41, 26 April 2009 (UTC)
As with your similar question at Sun, "Moon" (capital-"M") refers exclusively to (and is the proper name in English for) Earth's only natural satellite. The word "Moon" originally applied only to the Moon, but lower-case "moon" came to be a generic term as satellites of other planets were discovered. "Earth's Moon" would also be a somewhat clunky title. --Ckatzchatspy 03:41, 26 April 2009 (UTC)
As before, agree with Ckatz. Like the previous Sun/star, it is Moon/moon. Less obvious, but there. Awickert (talk) 03:47, 26 April 2009 (UTC)
[Stupid commit removed by author]Emmette Hernandez Coleman (talk) 04:00, 26 April 2009 (UTC)
Ckatz,if you are worried about a false implication as with Changing "Sun" to "Earth's Sun", this article could be named "Earth's moon".--Emmette Hernandez Coleman (talk) 04:14, 26 April 2009 (UTC)
About "Earth's Moon being 'a somewhat clunky title", so what--Emmette Hernandez Coleman (talk) 04:22, 26 April 2009 (UTC)
Earth's moon means the exact same thing as Moon, except it is longer, is less common in general speech ("I'm looking at the Moon"), and is already a redirect to this article. Both are equally descriptively valid, but "Moon" is used more, is easier, and is more likely to be searched for. Therefore, let's stay with the current title. Awickert (talk) 04:25, 26 April 2009 (UTC)
"Earth's moon" is still clearer then "Moon". About "Earth's moon" being longer then "Moon", so what, "Earth's moon" is not significantly harder to read then "Moon". About "Moon" being more likely to be searched for, sense Wikipedia has automatic redirects I do not see how that matters. About "Moon" being easier then "Earth's moon" I am not sure what you mean.--Emmette Hernandez Coleman (talk) 11:37, 26 April 2009 (UTC)
Agree with Ckatz. There is only one capital-M moon. When people talk about "the moon", there's no doubt they're talking about this one and not some other natural satellite. If they're looking for the general case, there is a dabnote at the top of article to help them get to the right place. Franamax (talk) 15:02, 26 April 2009 (UTC)
Franamax,you are arguing that the current state is clear enough, but why not make it clearer.--Emmette Hernandez Coleman (talk) 15:32, 26 April 2009 (UTC)
Because it can't be made any simpler. The IAU official name for "Earth's moon" is "Moon" and the term most widely used for "Earth's moon" is "Moon". The first line in the article explains the article is about Earth's moon. Article titles are not used to explain things, they're used to differentiate topics. The primary topic gets the plain name unless there is a major competing usage. Last month, Moon got 248,000 views, natural satellite got 30,000 and the dab page got 4,000. I don't see where people are getting confused by the naming. Franamax (talk) 16:12, 26 April 2009 (UTC)
How would you (of anyone else) feel about changing the title to "The Moon","The moon" ,"Moon (Earth)" "I stll think it should be "Earth's moon".--Emmette Hernandez Coleman (talk) 16:37, 26 April 2009 (UTC)---------Update: I no longer endose Moon (Earth) because it would be more confusing then "Moon--Emmette Hernandez Coleman (talk) 23:26, 16 May 2009 (UTC)
I think that the disambiguation at the top makes it perfectly clear, and the fact that it is the IAU name for the object makes it the proper title for the article. Now to send it back to your court, are you bringing this up because you're worried about clarity, or because you had trouble finding "natural satellite"? Awickert (talk) ~16:50, 26 April 2009 (UTC)
I am worried about clarity, and I realise that changing "Moon" to "Earth's moon" to the moon would only be a slight clarity improvement, but slight is better then nothing. This debate sure is fun!--Emmette Hernandez Coleman (talk) 17:00, 26 April 2009 (UTC)
I think the redirect at top is enough. As I said with "Sun", generally the most common usage is given the least-qualified name. Once one starts reading the article, it is clear that it is Earth's moon, and if that's not what one wants (a minority occurrence, it seems), then there is a direct link to natural satellite. Also, if we did this, "Moon" would have to become a disambiguation page, which I don't think would be useful. Awickert (talk) 17:55, 26 April 2009 (UTC)
Why would "Moon" have to become a disambiguation page?--Emmette Hernandez Coleman (talk) 18:03, 26 April 2009 (UTC)
What else is it going to do? If it redirects to "Earth's moon", it seems a little silly. Awickert (talk) 18:11, 26 April 2009 (UTC)
Why would it be silly?--Emmette Hernandez Coleman (talk) 18:52, 26 April 2009 (UTC)
Also, as "Moon" is the official IAU name, there seems little reason to change it except for the capitalization ambiguity. "Moons" does redirect to "natural satellite", taking care of some of this. Awickert (talk) 17:57, 26 April 2009 (UTC)
If I am going to search for this article, I will type Moon into the search box and press enter, most people will not think about typing Earths Moon into the search box. As above, Moon is also the proper name for the object, so I think renaming the article would just be silly. Martin451 (talk) 22:00, 26 April 2009 (UTC)
"Moon" could redirect to "Earth's moon". If the proper name and title of this Article were "Luna" (and I'm not saying the proper name is not Luna, I do not know if it is) would you oppose renaming the Article "Moon"?--Emmette Hernandez Coleman (talk) 22:32, 26 April 2009 (UTC)
Well you can quite easily verify what the proper name is, just by consulting the reliable and authoritative source we use, the International Astronomical Union. As I said above, it is "Moon" (or Earth I, I hope you're not going to suggest that next). We use the proper name for articles wherever possible. And as I also said above, we don't use titles to explain articles, we explain in the articles. Franamax (talk) 06:58, 27 April 2009 (UTC)
Thanks for the Information, I will take a look at the IAU but you MIGHT (not are might) be missing the the 2nd main point of of my last post, If the proper name and title of this Article were "Luna" would you oppose renaming the Article "Moon"? Also however proper "Moon" is, it is not the common way to refer to the Moon, "the Moon" is. Maybe the article should be renamed "The Moon", not as good a title for this article as "Earth's moon" but beater then "Moon". Also we do use titles explain what articles are about.--Emmette Hernandez Coleman (talk) 15:43, 27 April 2009 (UTC)
Sorry Franamax, ween I made the above post I thought you were Martin451.--Emmette Hernandez Coleman (talk) 15:49, 27 April 2009 (UTC)
Franamax, in response to what you said about simplicity, isn't simplicity in article titles just a means to the ends of clarity--Emmette Hernandez Coleman (talk) 19:05, 21 May 2009 (UTC)

It is common to drop "The" in encyclopaedic entries. e.g. the article on The Atlantic Ocean is just Atlantic Ocean. Martin451 (talk) 23:21, 21 May 2009 (UTC)

"Atlantic Ocean" could not be confused for oceans in general, "Moon" can be confused for moons in general. "The Moon" "Earth's moon" can not.--Emmette Hernandez Coleman (talk) 20:30, 22 May 2009 (UTC)
I see ya'll are havin' lots of fun with this! Emmette, while you don't seem to be able to gather a consensus on this issue, rest assured that this does not mean that you're incorrect. The very best name for this article might be The Moon or Earth's Moon (I personally prefer The Moon), and simply calling it Moon is actually just a tad ambiguous; however, this is appropriately covered by the hatnote, which immediately disambiguates the title. So calling the article Moon coupled with the appropriate hatnote is, for all intents and purposes, acceptable according to Wikipedia guidelines.
Yet another consideration, though by far not really all that important, is how much work that's involved in moving (renaming) a page. Even moving a simpler page will sometimes entail a long "cleanup" period. If you've been involved with other page moving/renaming, then you can imagine how long it might take to do the followups on a popular page like Moon. So to rename an article entails so much more than it seems to entail on the surface. While I agree with you that title clarification would be somewhat helpful, the most important consideration, for me, is the general reader, and the present title appears to work just fine for that category.  .`^) Paine Ellsworthdiss`cuss (^`.  20:35, 30 May 2009 (UTC)

Similarly for "the Milky Way", our article is at Milky Way. Emmette, yes, we aim for clarity in article titles but also for simplicity. We only start adding extra words when it's necessary to disambiguate between topics. For instance, we don't title the article "Milky Way galaxy" - that's what I meant earlier when I said we don't use titles to explain things. Now if there was some other major usage for Milky Way, we would then have Milky Way (galaxy) and Milky Way (dairy) or such-like, but only to distinguish between the two. You can read about article naming at WP:TITLE, WP:NCASTRO and WP:DAB. Franamax (talk) 02:24, 22 May 2009 (UTC)

I think I have seen encyclopedias use "The Moon" more then "Moon" as article titles, but my memories of this are vague, so I could be wrong. I think we have pretty much exhausted all the arguments we can make.--Emmette Hernandez Coleman (talk) 21:31, 29 May 2009 (UTC)

this user is a sock puppet

[From Terry0051] I'd vote to keep Moon. Reasons: 'Moon' is in general colloquial and scientific (IAU) use in English, and has colloquial equivalents in many, perhaps all, other languages (but Latin is no longer colloquial, and even if it had been, the Latin equivalent is very arguably not colloquial in English). The moon has a history of thousands of years of observation and study, and for all but the last 400 there was nothing else known that could be compared with it. After Galileo discovered the largest satellites of Jupiter, they were called by a number of descriptions and names, including secondary planets and satellites, and perhaps for short convenience they began to be called Jupiter's moons by analogy with the position of the moon. Against this background it seems very arguably perverse to call the moon anything other than the moon. If any bodies are in need of being distinguished, it's surely the satellites of other planets. 'Earth's moon' sounds like something that might perhaps be fictitiously colloquial in some virtual realms of science fiction, but until that has changed real-world usage I'd suggest keeping to current real-world language. Terry0051 (talk) 20:11, 30 May 2009 (UTC)
I see no reason to change it. There is only one fundamental topic that meets this simple name. There is nothing approaching the significance to waste people's time clicking around to find it. The general policy is to avoid articles at the start of names. The shear importance of the topic, and the variations in the use in text call for simplicity. Requiring a construct such as "the [[Earth's moon|Moon]]" in an article about poetry or "Earth's [[The Moon|moon]]" in an article about tidal forces seems overly complex. Keep it simple; keep it user friendly; keep it "Moon". Novangelis (talk) 01:27, 31 May 2009 (UTC)
Well, Novangelis, that's the beauty of renaming an article using the Wiki software. "Moon" would redirect to the new article name. However... as the editor, GTBacchus, points out below, that's the end of the "fun". After that there are lots of other stuff that needs to be done with the images, redirects, etc. And a popular, heavily-linked-to article like Moon would present literally hours of post-renaming, editing "fun"! Now... who would like to volunteer? <g>  .`^) Paine Ellsworthdiss`cuss (^`.  02:45, 31 May 2009 (UTC)

If it ain't broke, don't fix it. Moving this page would entail changing thousands of links and redirects, and would not improve the encyclopedia in a way at all commensurate to the work involved. Unless it is somehow clear that actual readers are unable to find their way to the appropriate article... I see no reason to change something that works. No one is less well-informed due to the current set-up. -GTBacchus(talk) 01:38, 31 May 2009 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Barycenter in the lead

An editor removed the "barycenter" description from the lead. I reverted the edit per WP:STATUSQUO, and would like to find out why that editor considers the description of the barycenter unimportant in that article position? While I do not agree with nor support this edit, it might be a good edit, or not; however, since this article is a Featured Article, it is important to closely scrutinize such edits so as not to lower the quality of the article.  .`^) Painediss`cuss (^`.  17:55, 17 May 2009 (UTC)

Skip to TOC

I've added the {{skiptotoctalk}} template at the top of this Talk page for those who want to "get right down to it".  .`^) Painediss`cuss (^`.  17:59, 17 May 2009 (UTC)

Too many pictures, not clear enough!

Please, folks, think of the results before uploading yet more moon pictures!

There's a risk of cluttering up this good featured article with pictures that make things less clear than they had been before.

For example, I'd be puzzled by the big picture with lots of phases on it if I didn't already know about moon phases. For one thing, it doesn't indicate where the light is coming from!

Best wishes, Terry0051 (talk) 15:51, 23 May 2009 (UTC)

Annoying blinking image in article

Am I the only one distracted and annoyed by the animated image of light traveling from the earth to the moon? With the high contrast and blinking effect, I half-expected to see "You've Won! Click here!" when I looked closer. Does this image provide value to the article? If so, perhaps there is a way to exhibit the concept in a more subtle animation. Maghnus (talk) 18:22, 29 May 2009 (UTC)

[From Terry0051] I agree with you the image is not good value. Light-time is not the most striking fact about the moon. I suggest it would be fine just to say it takes the light 1.255 secs on average or however long it is, instead of animating it. Terry0051 (talk) 19:30, 29 May 2009 (UTC)
Perhaps someone can figure out how to replace this with the same image, but unanimated, and a note to click the image to see the animation?  .`^) Paine Ellsworthdiss`cuss (^`.  03:26, 31 May 2009 (UTC)
Okay, check this out...
The relative sizes and separation of the Earth–Moon system are shown to scale above. Click here to see a beam of light depicted traveling between the Earth and the Moon in the same time it actually takes light to scale the real distance between them: 1.255 seconds at its mean orbital distance. The light beam helps provide the sense of scale of the Earth-Moon system relative to the Sun, which is 8.28 light-minutes away (photosphere to Earth surface).

So we see that it can be done. Since Moon is a Featured Article, before this image replaces the one in the article, it would be best to see if there is a consensus among involved editors to make this change. So...

Hey, ya'll! I now invoke an informal Request for Comment: Would this FA be improved by using this unanimated image in lieu of the animated image that is now in the article (in this section)? Please note that there is a link to the animated image in the unanimated image's caption. Also, copyright is covered under GFDL for both images.  .`^) Paine Ellsworthdiss`cuss (^`.  04:29, 31 May 2009 (UTC)

[From Terry0051] I agree the un-animated image would be a bit less annoying than the blinking one. On the other other hand, even that seems over-complex and fiddly, for the amount of information conveyed.
Why not just say it plainly in words? Actual words also bring the advantage of allowing brief informative description of what the figure 1.255 seconds really means.
The figure of 1.255 seconds seems to come from combining the speed of light (299792.458 km/sec) with a now somewhat old estimate for the mean earth-moon distance (384400km), after subtracting the semidiameters of earth (6378km) and moon (1738km)from the distance. So the intention behind the quoted figure appears to have been to indicate the mean surface-to-surface light-time (approximately) along the line of centers. A more up-to-date measurement for the mean earth-moon distance (between centers of mass) is 385000.5km (plus a few more decimal places, irrelevant here) (source: lunar solution ELP/MPP02, December 2002, from SYRTE, Bureau des Longitudes, Paris, based on analysis of LLR observations). It would be better to round the 1.255 secs to 'about 1.26 seconds' and call it the 'surface-to-surface light time along the line of centers at mean earth-moon separation'. This would take adequate account of the new figure and avoid giving more precision than makes any real sense in this context. Terry0051 (talk) 09:27, 31 May 2009 (UTC)

Does the location of Moonrise vary?

I might have missed it, but does the main article have a paragraph on calculating the specific point on the horizon where the moon rises? Does this location change from month to month, or even day to day? Yes, I understand that sometimes the location of the sun prevents the moonrise from being visible, and sometimes the phase of the moon makes it completely dark to us, but it rises anyway.

So, I looked all over for a simple description of the formula for calculating the point of moonrise (and not the particular minute or hour), and simply can't find it.

I think the main article could be improved if there were an explanation of what the Lunar Ecliptic is, and how it differs from an ordinary ecliptic, which I take to be the apparent range of the sun's motion over the earth. 216.99.219.32 (talk) 06:39, 16 June 2009 (UTC)

I looked into this a bit and found an interesting calculator, explained here. A sample output is here. I think you'd be interested in the "Azimuth" figures, but I'm not totally sure.
You can always ask about this stuff at our science reference desk, where a wide selection of pretty smart people hang out waiting to jump on questions like this. :) Franamax (talk) 13:34, 16 June 2009 (UTC)
Well, why put the formula off for later, when it could be discussed here and now?
Okay, so if I know the specific date in the year, down to the hour and minute, and if I know what the observer's longitude and latitude is, how would I juggle these variables to get the location of the moon in the sky, as it would appear to the observer? 216.99.201.232 (talk) 17:23, 16 June 2009 (UTC)
Why put it off? It's probably too detailed for this article. A simple statement of predictability of time and position should suffice. Something as involved as the equations is too technical for this article. Such detailed information belongs elsewhere, such as in an article about astronomical predictions and tables or in its own article, akin to sunrise equation. Novangelis (talk) 18:20, 16 June 2009 (UTC)

last paragraph in "Presence of Water" section of "Moon" page

The current version uses strange, technically incorrect language, and does not use primary sources:

In July 2008, small amounts of water were found in the interior of volcanic pearls from the Moon (brought to Earth by Apollo 15).[1]

I would suggest making the following changes:

In 2007, small concentrations of water (up to 0.005%) were found inside volcanic glass formed by surface eruptions on the Moon (and sampled by Apollo 15). The discoverers of this lunar water also found sulfur, chlorine and fluorine, and argued that the water concentration of these glasses was originally about 0.05%, a possible challenge to the commonly accepted giant impact hypothesis of lunar formation. .[2][3]

Fixed it. - RoyBoy 05:50, 17 December 2008 (UTC)

Double Planet 3

I intended to create this new division to discuss proposed rewording for the "double-planet" hypothesis and I'll supply that on request. I would like to get this solved but I couldn't resist the dang calculator and associated algebra.

I calculated the Moon orbital radius (RM where the graviation force would be balanced between Earth and Sun. This is approx 259,111 km, and please do check my figures. Now Earth-Moon are tidally locked with the result that Moon recedes from Earth, according to our article at 3.8 cm/yr. Plugging in the numbers (again, please check!) and admittedly using only the current figure, this indicates that the Moon entered the "continuous-convex" orbit regime only 3.4 million years ago. Yes, we do wish to report the latest information on-wiki, but 3.4Myr is an eyeblink in geologic/universe time.

This is totally OR but makes me unwilling to propose a new wording. What we need is RS addressing the issue. Asimov, whilst interesting, may have chosen to overlook this in the interest of creating a saleable article. Franamax (talk) 09:33, 26 March 2009 (UTC)

If you can get a source for this new information that the Moon was recently wavy, then we can add it. But that's a separate issue. For now, let's focus on the information we already have confirmed. Again, I propose this alternative wording for the article:
The Moon is exceptionally large relative to the Earth, being a quarter the diameter of the planet and 1/81 its mass. The Sun's gravitational pull on the Moon is approximately twice as strong as the Earth's pull on the Moon. From the Earth's perspective, the Moon appears to circle the Earth by moving in a retrograde direction in relation to the Sun. However in reality, the Moon always moves forward in its yearly path around the Sun, and its path around the Sun is convex. The appearance of retrograde motion is a result of the fact that when the Moon is ahead of the Earth in their orbit of the Sun, the Moon keeps moving forward, but it slows enough to allow the Earth to pass it. Some people consider the Earth–Moon system to be a double planet system rather than a planet–moon system[4], although most astronomers still considered it to be a planet-moon system, since the common centre of mass of the system (the barycentre) is located about 1,700 km beneath the surface of the Earth (about a quarter of the Earth's radius). The surface of the Moon is less than one-tenth that of the Earth, and only about a quarter the size of the Earth's land area (or about as large as Russia, Canada, and the U.S. combined).
It's a bit wordy, but anything less and we run the risk of the average person not understanding it. We've certainly had enough trouble understanding it, and we know a lot more about this than most people. - Shaheenjim (talk) 12:19, 26 March 2009 (UTC)
I'm sorry, but if you want to add that, then you're going to have to find references. Asimov is only a reliable source for his own opinion, nothing else. I want to see peer reviewed physics or astronomical articles or other authoritative source. This is a featured article, and so we shouldn’t settle for anything less. 189.105.2.177 (talk) 13:23, 26 March 2009 (UTC)
That's fine. We can use the same sources that are used on the other Wikipedia articles that say the exact same damn thing, but where people don't throw a fit about it. - Shaheenjim (talk) 13:33, 26 March 2009 (UTC)

Shaheenjim has been blocked indefinitely. See his talk page. --116.14.26.124 (talk) 09:40, 3 July 2009 (UTC)

Rotation (Two sides of the Moon)

The article states: The Moon is in synchronous rotation, which means it rotates about its axis in about the same time it takes to orbit the Earth.

This is not quite correct: the moon does not rotate about its own axis, but performs just the same as the wooden horse in a merry-go-round as seen from an observer that is standing at the rotating center of the merry-go-round. That horse is actually performing a synchronous rotation, but obviously it does not rotate about its own axis, but the axis of the merry-go-round.

Therefore, the moon also does not rotate about its own axis, but the axis of the Earth.--Nemowiki-EN (talk) 08:54, 16 June 2009 (UTC)

Or actually about the barycenter. But if the moon had no rotational momentum, it would revolve around the earth while facing the same "fixed" stars. It doesn't: in addition to revolutionary momentum (not a political offense for astronomical bodies), it also rotates. The two are simply matched in period, when averaged over time.
Take the other extreme: the Earth does not rotate about the barycenter either. kwami (talk) 09:19, 16 June 2009 (UTC)

The idea of the synchronous rotation is just a mathematical trick to express the rotational momentum. In that respect it is correct to split the motion of the moon into two rotating movements: one around the earth, the other around itself. You could do the same trick with the wooden horse on the merry-go-round. Of course, this is mathematically (and physically) correct, but you could just as well spilt it into n motions around n axes. But does the explanation of the actual movement improve by splitting it up into n combined movements? I do not think so. It is helpful for mathematic reasons, but detrimental to the understanding of the actual movement. That horse is rotating around an axis that is rotating around an axis that is ... --Nemowiki-EN (talk) 10:18, 16 June 2009 (UTC)

Isn't the better statement that the moon rotates around its own axis at the same rate as it revolves around the Earth-Moon barycentre? Not sure on the exact math, but aren't all those motions determined by reference to the distant stars? Wikipedia is a distant star. Franamax (talk) 13:16, 16 June 2009 (UTC)
Not really. Rotation and revolution are two different entities. Rotation is the movement about the axis of the body. Revolution is the movement about the center of mass of the system. The merry-go-round analogy is flawed as there is a strict coupling of the horse to the carousel. The rate of revolution is not a constant since the orbit is elliptical. The revolution about its axis is closer to a constant (I don't have the exact numbers or a good source handy). The Moon's longitudinal libration is the consequence of the differences in variations from constancy.Novangelis (talk) 18:06, 16 June 2009 (UTC)

"Luna" in introduction

I disagree with this edit. The Latin translation does not belong in the first sentence of the lead. it breaks up the flow of this critical sentence too much. The etymology section already mentions that the moon's latin name is sometimes used. If it is really critical, this could be mentioned in a sentence in the lead as well, but it should not be inserted in parenthesis in the first sentence. Contrary to Martin451's edit comment, I don't think "Luna" is all that commonly used anyway. "Luna eclipse" is incorrect. The correct English phrase is "lunar eclipse", where "lunar" is the adjective relating to the moon. The adjective is covered, as is usual, in the infobox just to the right of the lead section. I would be amenable to introducing the adjective "lunar" in the lead section as well (but not in the first sentence), as this term may be unfamiliar to some readers.--Srleffler (talk) 22:19, 24 June 2009 (UTC)

I agree with Srleffler that a reference to the Latin 'Luna' is out of place in the lead sentence of this English-language article about the Moon.Terry0051 (talk) 00:01, 25 June 2009 (UTC)

I removed the latin translation, but linked the first occurrence of "lunar" to the Wiktionary entry, in case a reader is not familiar with this term and doesn't notice the infobox.--Srleffler (talk) 05:44, 27 June 2009 (UTC)


Luna is used as a proper name for this planets moon, not just by science fiction but by scientist working within this field. A good example of this is when comparing our moon with that of other moon, which can quickly become confusing. Luna is largely accepted as the proper name and Moon a common name, just as Felis domesticus is the proper name for the house cat. —Preceding unsigned comment added by 62.49.71.10 (talk) 10:04, 24 July 2009 (UTC)

Earth I

Is “Earth I” a valid name of the Earth's natural satellite? --88.78.13.178 (talk) 14:32, 28 June 2009 (UTC)

Yes it is. [1] Franamax (talk) 18:03, 28 June 2009 (UTC)

Please give a reason why, I know it a common feature of sci-fi but that dosn't make it valid. 89.168.56.242 (talk)

Roman numerals are part of the standard astronomical nomenclature for natural satellites. Follow the USGS link above to see an example of this for Earth's moon. --Stepheng3 (talk) 01:54, 25 July 2009 (UTC)

Archive issues

I combined the multiple archives that only had one thread per archive. I also increased the size of the archive and I may have fixed the bug that was creating the many small archives. I do not follow this talk page, so if you need me, drop a note on my talk page. Vegaswikian (talk) 19:52, 12 July 2009 (UTC)

Thanks Vegaswikian. I have no idea what cause the issue with archiving, but I was certainly happy to see that you were (and have, apparently) straightened it out.
V = I * R (talk) 22:01, 12 July 2009 (UTC)

New lead additions

A good bit was added to the lead today. Is it appropriate to include this new information there or should it be moved down to the "exploration" area. I might should be being bold, but I'm still easing into wikipedia... I did remove a part of a sentence that seems speculative. Cmiych (talk) 19:19, 14 July 2009 (UTC)

If you think that it should be moved, then you should definitely go for it. That's how Wikipedia works and is improved, after all.
As for the last half of the sentence which you removed, be sure to check the references. Speculation is OK as long as it's reasonable and well referenced (no fringe theories being the biggest issue). So, I put the sentence back, but don't let that discourage you at all. This is one surefire way to generate communication, with the key being that you actually came here and started a topic about it on the talk page.
V = I * R (talk) 19:48, 14 July 2009 (UTC)

Why is this here

"The U.S. has committed to return to the moon by 2018." I have removed it because 1) It has no relavance 2) Beyond some PR cash & blarmy, NASA has done nothing that indicates it will happen & 3) So what, it shouldn't be in the introduction anyway. 89.168.56.242 (talk)

Seems the page is semi-protected, must have missed that so i will leave it to registered users to get rid of that line while i go register.89.168.56.242 (talk)

I brought up the same thing about a week ago, but other seemed to believe it was worth inclusion... That statement in the lead is actually much trimmed down from what was originally inserted... Cmiych (talk) 05:14, 21 July 2009 (UTC)
NASA is planning a return mission in the 2020s - Constellation Programme 88.105.5.75 (talk) 18:30, 23 July 2009 (UTC)

Tempted to pull it out. The refs are all from 2005 articles. I just spent some time looking at internet articles on the recent 40th anniversary of the first moon landing, and found a wide range of opinion on what is up with the "U.S. return to the moon" concept - it seems a bit doubtful if the money is there, etc. Await more info and opinion here. Jusdafax (talk) 07:13, 4 August 2009 (UTC)

there is no planned date for a return to the moon, so you can just remove it. Since 2005 the budget has been cut and plans have been changed. A recent presentation by dr. sally ride of the augustine hsf review committee estimated how future nasa human space operations would play out if the status quo remained, and with information from aerospace corp and nasa, she said it was unlikely that orion and ares 1 would be complete by 2020 if the status quo remained. the lunar lander, which is not even designed yet, was not even mentioned —Preceding unsigned comment added by 76.11.124.147 (talk) 17:29, 8 August 2009 (UTC)

Full moons closest to the earth (Perigree)

The mention of certain dates when the moon is full, but the orbit's mileage moves closest to the earth. This happened three times in the last 20 years (on average every 9.5 years) such as the full moons of Dec. 1-2, 1990, Dec. 20/21, 1999 (the first day of northern hemisphere winter with the longest duration of twilight) and Dec. 12/13, 2008. A similar near-approach to earth was Jan. 11, 2009 and Dec. 30/31, 1990 on New Years' eve, thus it can occur twice in a single lunar month or 28.5 days apart. The next full moon in ultra-perigree (or 330,000 to 350,000 km from earth) is in on Christmas night Dec. 26, 2017 or a near-approach on Nov. 25, 2017. Winter full moons happen to be on a higher horizon on the epilpetic in the northern hemisphere, about 23 degrees North (or 20-21' N in the year 2017), and the 1999 Winter solstice full moon was located in 20-21' degrees north. + 71.102.3.86 (talk) 07:14, 28 July 2009 (UTC)

Request to alter "The Moon" file.

I konw information on the formation on the moon and would like to place it in "The Moon" file. It tells the way on how the moon formed. --Thunder 21:28, 1 August 2009 (UTC) {{editsemiprotected}} --Thunder 21:27, 1 August 2009 (UTC)

OK...that would be great. If you have some references to reliable sources, then please add the info. Cheers!  Chzz  ►  23:05, 1 August 2009 (UTC)

I thought a section like this would be a good inclusion to the article; as it would show more about how people percieve the moon and the mystery/whatever it "contains" - and just how the moon's depicted as being like. —Preceding unsigned comment added by Kurtle (talkcontribs) 19:06, 3 August 2009 (UTC)

"although a few robotic landers and orbiters have been sent to the Moon since that time."

remove "a few". imaginary quantification. —Preceding unsigned comment added by 76.11.124.147 (talk) 17:19, 8 August 2009 (UTC)

Cruithne, et al.?

How about some mention of the other natural orbiting bodies, such as Cruithne? —Preceding unsigned comment added by 68.83.72.162 (talk) 01:30, 17 August 2009 (UTC)

3753 Cruithne does not orbit the Earth. Cruithne orbits the Sun, and it's orbit is influenced by the Earth. -- Kheider (talk) 02:25, 17 August 2009 (UTC)

Moon Rocks category

How come the 'Moon Rocks' paragraph does not tell "which" minerals are present on the moon? I understand from a recent article (http://www.starstryder.com/2009/03/24/the-moon-is-made-of-minerals/) that there are plenty of different types of minerals on the moon, not just the 'basalt' described here on Wiki. 132.8.8.45 (talk) 20:50, 4 September 2009 (UTC)

Orbit and relationship to Earth

The "Diagram illustrating various phases of the Moon in their order of ...", to my best, is not true. The diagram shows the trajectory of the moon to be at times convex and at times concave when it should be always convex. Please see the article "Orbit of the Moon" the section "Path of Earth and Moon around Sun". (JJCP (talk) 21:02, 5 September 2009 (UTC)). —Preceding unsigned comment added by JJCP (talkcontribs) 20:59, 5 September 2009 (UTC)

I think the problem is that it wouldn't be possible to show the concave motion within such an image. If you click on the image itself and read the "Summary" text, it states that the representation could be misleading. As you note, we have an article to make the true motion clear. Hopefully, none of our readers will draw conclusions based only on a line in an image. Franamax (talk) 22:10, 5 September 2009 (UTC)

[From Terry0051] I think JJCP has a point if you look at the image closely enough, because the various 'Earths' seem to be shown as stages on Earth's journey around the Sun shown much too slow relative to the Moon, the Moon looks here as if it is whizzing round at a rate that the geometry would indicate as several tens of months each year, and going retrograde each month, which it doesn't in fact do. It's a very poor and unsuitable image for another reason as well, because it introduces the nearly irrelevant feature of the earth's orbit round the sun, and fails to demonstrate the vital ingredient for moon-phases, which is the angular relation between Moon and Sun as seen from the Earth. The old fashioned circular diagrams with about 8 Moon phases in relation to the direction of the Sun were much clearer in respect of the point to be demonstrated. I'll see if I can find a usable one. Terry0051 (talk) 22:24, 5 September 2009 (UTC)

Yes, I forgot in my last post to ask whether a better image is available. It seems to me that if we wished to show the Moon motion properly, we would need very w-i-ide display screens. So the question becomes: what is the main purpose of this illustration? And is there any way that the image caption can be tweaked to make the intent more clear? I rather doubt that the purpose of this image is to prove any facts about the Moon's orbital relationship to the Sun. Franamax (talk) 00:13, 6 September 2009 (UTC)

[From Terry0051] This post is again about a possible better image for demonstrating (more clearly than we have at present) the cause of moon-phases:-- The kind of thing I referred to in last post was rather like File:NSRW_Phases_of_the_Moon.jpg. That image seems clear enough about the relation with the Moon's monthly journey around the Earth, but the drawback I see is that this image contains no explicit indication of the direction of the Sun. Of course in a sense it's obvious that the Sun is way off the top of the image in the upward direction, but I take it that the purpose is to make things clear to a reader who isn't yet oriented to all of that. Is there anything better around? Terry0051 (talk) 22:11, 8 September 2009 (UTC)

It would be nice to have a link it "Metonic cycle" in the "See Also" section. —Preceding unsigned comment added by 70.176.54.38 (talk) 05:55, 18 December 2009 (UTC)

If the moon's Radius is about 1/4 that of earth's, it's surface area should be about 1/16th that of earth's (which should correspond to the area of Russia) instead of the posted 1/4 Area. —Preceding unsigned comment added by 71.56.202.162 (talk) 21:43, 21 December 2009 (UTC)

  1. ^ Versteckt in Glasperlen: Auf dem Mond gibt es Wasser - Wissenschaft - SPIEGEL ONLINE - Nachrichten
  2. ^ [2]
  3. ^ [3]
  4. ^ Asimov, Isaac (1975). Just Mooning Around, In: Of time and space, and other things. Avon.