Talk:Moon/Archive 6

The Moon's Movement Away From The Earth

I'd like a little more information with regard to this statement: The Moon will continue to move slowly away from the Earth until the tidal effects between the two are no longer of significance, whereupon the Moon's orbit will stabilise.

I take it that means that once the Moon's orbit stablizes, the Moon will not move further away from Earth. Also, have scientists determined how long it will be when this happens? —Preceding unsigned comment added by 157.174.221.169 (talk) 19:14, August 28, 2007 (UTC)

Moon The Only Natural Satellite!

Cruithne, discovered in 1986, is another natural satellite and is a temporary moon of the earth which may become a permanent moon. So to say that the moon is the only natural satellite of the earth is false, especially since scientists believe there are more temporary moons than just Cruithne. I haven't changed the article in reference to this, but it does need to be changed.

Here is a quote from Space.com (http://www.space.com/scienceastronomy/solarsystem/second_moon_991029.html):

"Earth has a second moon, of sorts, and could have many others, according to three astronomers who did calculations to describe orbital motions at gravitational balance points in space that temporarily pull asteroids into bizarre orbits near our planet.

The 3-mile-wide (5-km) satellite, which takes 770 years to complete a horseshoe-shaped orbit around Earth, is called Cruithne and will remain in a suspended state around Earth for at least 5,000 years."

There is some debate as to whether it can be classified as a moon, though the term "temporary moon" seems to satisfy everyone. However, it is indeed a natural satellite and is referrenced as such in the quote above.

That could mean satellite of the sun, or it could just be grasping for a term to refer to something that's hard to categorise. Wikipedia has a page on it 3753 Cruithne. Looking at the orbit simulations I wouldn't count it as a satellite of the Earth but that's just me. The type of object is on Wikipedia page Quasi-satellite. CaspianM 14:55, 1 November 2006 (UTC)

POVdeRursus: The scientists mentioned speak rubbish, by my account - a satellite is a non-star astronomical body orbiting a planet. A moon, by my subjective POV, is a huge satellite. Now to be precize about orbiting a planet, this means (my subjective POV again) that the gravitational force from the planet by far supersedes the gravitational force from the sun as applied upon the satellite. The chaotic and dysfunctional process of the professional astronomers as regards to the definition of planet, clearly demonstrates to us that they're not prepared with the necessary linguistic insight to make definitions about anything - yet. That was not meant to prove anything, except to say that "IMHO Cruithne isn't a satellite to Earth", and maybe we should be a little cautious of listening to how astronomers speak (and besides, I got the chance to make a small revenge to the astronomers for producing crap-definitions, heheehhehee!!!) Rursus 15:48, 15 November 2006 (UTC)

By your standards, we would not have a Moon. The Sun pulls the Moon harder than we do.Saros136 15:56, 15 November 2006 (UTC)

By Jove, You're right!

pl	m - mass kg	d - dist from Moon AE	G' = m/d²
Sun	1.9884e30	1	1.9884e30
Earth	5.9742e24	0.00255	9.1875e29

OK, then I've ever thought that the Moon was a little weak in performing it's role - so then we'll demote Moon to being a planet. ;-) Rursus 16:20, 15 November 2006 (UTC)

the moon/earth is a double planetary system. no other moon so affects its planet —Preceding unsigned comment added by 69.125.110.223 (talk) 17:11, August 30, 2007 (UTC)

Are there other co-orbitals, and are the ones listed correct? In the article it says "Three other near-Earth asteroids (NEAs), (54509) 2000 PH5, (85770) 1998 UP1 and 2002 AA29, which exist in orbits similar to Cruithne's, have since been discovered." In a book I have it claims that there are 7 indentified, Cruithne, 2000 PH5, 2000 WN10, 2002 AA29, 2003 YN107 and 2004 GU9. (Strangely the book only names 6?). I don't want to add this info, as I know very little about the subject, and the book is not a serious science reference, so could somebody 'in the know' check these details? 213.48.1.131 19:35, 2 January 2007 (UTC)

Suggestion: Why not change the opening sentence to, "The Moon is the largest of several natural satellites that orbit the Earth". This neither supports or opposes the idea that the Earth has more than one moon. I'd do it myself, but I'm newly registered, and the page is protected, presumably because people keep changing the definition to "The act of flashing one's buttocks to another person or group of persons".

Co-orbitals do not orbit the Earth. Saros136 08:49, 6 January 2007 (UTC)

I've tried to make changes to reflect this, however it gets reverted straight back (well within 12 hours) - any reasons why?Rufty 10:42, 5 March 2007 (UTC)]

A couple of points.

1.This article is not titled "The various moons, natural and artificial satellites and sundry orbiting debris of every size and shape of Earth and other planets". It is titled "The Moon". You know, the one we see just about every night? The heavenly body also called Luna? It's amazing that people can write thousands of words without pausing to consider whether they are simply arguing about the definition of a word. In this case, the confusion arises because the term "moon" is both a common noun (when it refers generally to natural orbitting satellites) and a proper noun (when it is used as the name of our very own moon, the biggest one we have).

2. If pedantry were compulsory, Wikipedia would have articles the size of an entire library on "Chewing gum". And the article would consist of so much hair-splitting and concern for exhaustively documenting the most insignificant counterexamples that no one would bother reading any of it, and if they did, they would hardly be wiser for it. I imagine that if some people were asked to write something on dogs, the sub-heading on "legs" would inform us that dogs had anywhere from 0 to 7 legs, with a mean of 3.81987, although some experts have disputed the exact figure. Given that if you define "a moon of Earth" as properly referring to any of our natural satellites, then every grain of interstellar dust in orbit is a moon, and thus must be dealth with here. No thank you. I know this is unfair to the peanut-shaped and sized Belllabonga moon, but I'm only interested in reading about Luna here. That's why your stuff is taken off as soon as you put it on there. It's boring. Why don't you start a New Encyclopedia called Inconsequentia. Myles325a 12:24, 8 April 2007 (UTC)

With respect, I think this is moot. What is or is not a satellite/moon is defined by the IAU, this matter has been settled. Winning an argument on Wikipedia does not mean winning in the real world. I was not particularly happy about the outcome of the Pluto controversy, but I grudgingly accept it because the IAU is the final arbiter in such matters. PrivateWiddle 19:45, 14 May 2007 (UTC)

It used to be two, but it has changed over the last couple of yeras. CorleoneSerpicoMontana 15:42, 28 May 2007 (UTC)

My understanding (and wikipedia backs me up here :-)) went that "A natural satellite is an object that orbits a planet or other body larger than itself and which is not man-made." in fact the IAU (http://www.iau.org/fileadmin/content/news/iau0601/iau0601_Q_A.doc) says "an object in orbit around the planet is called a “satellite”". So regardless of what anyone here wants to think Cruithne is by that definition a satellite of the Earth. Like Pluto is no longer a planet, Cruithne is a Satellite of the earth and therefore deserves mention here. I thought Wikipedia cared most about facts/official definitions? Rufty 16:33, 4 July 2007 (UTC)

Wikipedia does care about facts and official definitions. If you can get the IAU to officially state that Earth has two moons, one of them being Cruithne, then it will go in the article. Otherwise, there can be only one... --Ckatz^chat_spy 18:16, 4 July 2007 (UTC)

If the formal definition states that the asteroids under question are satelites, then the line "The moon is earth's only natural satelite" is technically a lie. Warren from calgary 13:44, 5 July 2007 (UTC)

There are 6 other NEA's that are orbiting earth. Adding Luna makes 7. The natural satellite statement is false, these other 6 are natural satellites. Their status as moons are questioned however. We haven't quite got a definition as to what makes a moon, and isn't top of the list. Getting a good solid ground for a definition of a moon could help us decide. So we could end up having something like what happened with Pluto. Cruithne has a strange "horse-shoe" orbit, which is one of the reasons why scientists would say it's not a moon. — Preceding unsigned comment added by Jamiepgs (talk • contribs)

Getting definitions of these things is not easy as they have arisen over history and new discoveries are showing there are no black and white boundaries. The new definition of planet caused uproar and is still not widely accepted. The Moon is accepted as our only natural satellite as it is the only one we could see for millennia and it is known its presence affects the earth. I would be interested to see what variety of definitions for "moon" people come up with but I would support keeping the statement that the moon is the earth's only natural satellite as to all intents and purposes it is true. Sophia 11:51, 15 July 2007 (UTC)

No amount of discussion, citation, or consensus will turn any of these bodies into the Moon. I suggest that further debate about Cruithne et al. be directed to Talk:Solar system. When the issue is resolved, the incidental sentence about the singularity of the Moon can be corrected - if necessary. Sheffield Steel^talkers_stalkers 19:39, 28 August 2007 (UTC)

Moon and colour

There are occasions where the moon is tinted a red colour due to the light passing through the atmosphere of the earth. However, the article makes no mention of it (it's not a lunar eclipse, as it happened less than two hours ago as I post this) and the moon is not in the Earth's shadow. Does this have a name? i think it should be included in the article.--Tiberius47 11:13, 2 February 2007 (UTC)

The "Copper Moon" is actually a lunar eclipse where the earth stands between the moon and the sun [1]. The earth's atmosphere causes some light from the sun to bend and fall on the moon which is why the moon is not totally dark and also what gives it the colour. I'll check the article and add missing details. Sophia 21:13, 12 February 2007 (UTC)

I think he's talking about when the moon is near the horizon and looks red or orange.thx1138 03:06, 13 February 2007 (UTC)

This occurs where the light reflected from the Moon has to pass through more atmospheric dust due to the shallower angle, and this causes the amount whereby the light is refracted to be greater, therefore in turn the light is changed to longer wavelengths. The same happens to the Sun. As for a name, God knows. Let's call it perihorizontal discoloration. Kris 22:30, 2 March 2007 (UTC)

Moon in the day

I'm just wondering if there is a technical term for when the moon is visible during the day. - Jigsy 16:02, 1 March 2007 (UTC)

Is there a technical term for the Moon visible at night, or when it's not visible (either obscured or below the horizon)?? I'm not sure. If not, there should be. Kris 22:22, 2 March 2007 (UTC)

The moon in the day is the new moon Roo 7 April

The moon in the day is not the new moon (notice how it doesn't go from full to "new" as night sets in? Just saying) John jarrell 22:55, 11 May 2007 (UTC)

intro

From the intro - 'The related adjective for the Moon is lunar (from the Latin root), but this is not found in combination with words using the prefix seleno- or suffix -selene (from the Greek deity Selene).' this is awkward - needs re-writing but I can't think of a good way to do it... sbandrews 00:15, 11 March 2007 (UTC)

I've had a go:

"The related adjective for the Moon is lunar (from the Latin root), however this is never found in combination. The preferred combining form is -selen- (from the Greek deity Selene), appearing as a prefix (seleno-, as in selenography) or suffix (-selene, as in aposelene)." Kris 09:43, 11 March 2007 (UTC)

better, thanks, the combination bit is still awkward - its probably not *entirely* obvious that we wouldn't say 'lunar selenography' (or 'lunography'!) but this seems a matter for an article on English grammer rather than an intro on the Moon...

"The related adjective for the Moon is lunar (from the Latin root) and words can also be combined with -selen- (from the Greek deity Selene), appearing as a prefix (seleno-, as in selenography) or suffix (-selene, as in aposelene)." sbandrews 11:54, 11 March 2007 (UTC)

It's misleading to say that "lunar" is never found in combination; if the adjective "selenic" applied to the Moon rather than to selenium, it would not be used in combination either. The article needs to distinguish between the related adjective and the related combining form. (In any case, the would-be combining form "luna-" is used in some Moon-related words, such as "lunatic", even though this is not an astronomical term.)

I think sbandrews' suggestion should therefore be modified to:

"The related adjective for the Moon is lunar (from the Latin root). However, the combining form is -selen- ... " — Paul G 10:10, 20 March 2007 (UTC)

Political viewpoint?

There's a section in the exploration that says

What was the next big step depends on the political viewpoint: in the US (and the western world in general) the landing of the first humans on the Moon in 1969 is seen as the culmination of the space race.

As opposed to what? The article doesn't expand on other political viewpoints (for instance the Eastern world viewpoint). It just expands and explains the US (Western world) Viewpoint. — Preceding unsigned comment added by 68.205.70.254 (talk • contribs)

Taken care of. Nick Mks 10:43, 3 April 2007 (UTC)

FA push

It seems to me that the people who made this article to what it is today (a fine piece of work just short of FA status) have lost their interest a bit after GA was achieved. I'd like to give it a try to give this one the final FA push it needs, starting later today. Any help is welcome of course. Nick Mks 10:48, 3 April 2007 (UTC)

On second thoughts, I don't see anything that I personally want to see improved. It also seems that all comments from the previous peer review have been taken care of. Let's just do it and address problems along the way. I'm nominating! Nick Mks 17:43, 3 April 2007 (UTC)

Yes, it's good. But good is the enemy of great. There are changes that need to be made, issues which require clarification. For example, the article displays instances of the widespread practice of employing technical terms without attendant definition or explanation. When such occurs, it is often manifest material has been lifted from some academic journal with little effort made to assimilate it to the needs of Wikipedians. Further, some material is improperly positioned, and has the misfit look characteristic of afterthoughts, or sops to the completists. The stuff on angular momentum should be given a sturdier, non-technical foundation. This is an area where there is some current interest due to the moon’s recession entailing a supposed consequence for some religious beliefs on the creation of the world. It would be timely to provide clarification of the extant data pertinent to this, not in a disputative or belligerent way, but in recognition that many are searching for pertinent information. But I don’t want to carp. It’s good, damn good. Myles325a 13:02, 8 April 2007 (UTC)

Allow me to respond to two of your quotes:

• This is an area where there is some current interest due to the moon’s recession entailing a supposed consequence for some religious beliefs on the creation of the world. I'm sorry, but I'm not getting into that. My experience (outside of Wikipedia) has shown that this is totally useless and sometimes outright dangerous.
• Oh, I think it is nit-picky to make such a pointed discrimination between "dark" and "far" side of the Moon. For all practical purposes the two are the same. That's a common misunderstanding, and exactly what the article tries to sort out. The far side is the side we never see from Earth, the dark side is the side that is not illuminated. So only when it is full Moon the two are equivalent. During new Moon, we see the near side (as always), which is then the dark side. Nick Mks 13:23, 8 April 2007 (UTC)

Oh. Yes, I withdrew my dark vs far comment almost as soon as I had written it. My typing finger slipped. (chortle). On point 2, don't get me wrong. I'm not saying get into this controversy. In my own case, I had often in years past, wondered WHY the Moon was moving away from the Earth. And the answer "Angular Momentum" didn't do it for me, because I couldn't see how the Earth slowing down on its axis could somehow cause the Moon to go further away. How was such a force transmitted, I pondered. Now, I believe I have it figured out, sort of. It has to do with the braking effect of the tides on the other body, but it is not AUTOMATIC that a slow down in the Earth's rotation is transmitted to the Moon. You could have the Earth slow down and not affect the Moon's orbit at all. This is important, if only for the reason that people who are interested in the Moon, will be interested in whether it is moving away from us, whether we are going to lose it, or if it will come back. And why. I think these are fair enough concerns. And if the YEC crowd happen to have a stake in it, it has nothing to do with Wikipedia. I don't think we should antagonise them, but I'm damned if I'm going to start avoiding issues because it conflicts with their medieval views. I have inserted one sentene to do with the Moon's recession. When I get more data, I will add it. In addition, I have made quite a few, mainly cosmetic and stylistic changes to the content. Hope you like it (well, most of it) Myles325a 16:59, 8 April 2007 (UTC)

Yes, absolutely, thanks for your input. As for angular momentum stuff is concerned, this is actually my speciality (but then for binary stars in stead of the Earth-Moon system). I do not feel at ease writing this down for a general audience though since it actually is quite mathematical, so feel free to give your view and I'll see if it's scientifically correct. Nick Mks 17:44, 8 April 2007 (UTC)

On second thoughts, are you sure that the system will ever be totally synchronous and stable? I know the lecture notes say so, but I always heard it would take longer to achieve that than the lifetime of the Sun. Nick Mks 17:54, 8 April 2007 (UTC)

Well, even so, it would still stop recessing in principle. Of course, this phenomenon (of combined angular momentum of planet and moon leading to the moon always facing the planet) is not unique to us. Mercury was thought to always face the sun, but maybe there's been some revision on that recently. OTOH, there are other moons that always face host planet. And not all of them are going to get eaten up by the dying sun. (Friend of mine told me his science teacher had told class that moon always facing Earth was one of those Great Coincidences like the sizes and distances of the Moon and Sun making perfect eclipses possible. One too many moon coincidence, huh?) I read that Moon would stop moving further out, and by that time, tides on Earth would be insignificant. Then, Moon would start moving back via gravitational radiation, but it would take untold billions of years before it would theoretically hit Earth. Makes sense to me. Will research it. BTW, was interested to read in article that Sun's tidal effect on us is half that of Moon's. I didn't think it would be even this much. I wonder if there are any calculations as to what the tides would be like if the Moon wasn't there. I suppose that with today's computers, it shouldn't be that hard to model. Myles325a 20:11, 8 April 2007 (UTC)

Many thanks to all for their comments and input! Nick Mks 07:05, 12 April 2007 (UTC)

Observations

This section included an image labelled "Moon reddened because of physical phenomena." I couldn't tell just what this phenomena was, and the image caption wasn't telling. Could someone clarify the matter? Until then, I've removed the image from the article. mdf 19:14, 4 April 2007 (UTC)

Maybe we better just drop it. It's not bad, but not a featured picture either... We could also drop the caption alone. I could write an entire paragraph on the atmospheric phenomena causing this, but that's got nothing to do with the Moon. Nick Mks 19:53, 4 April 2007 (UTC)

Image quality is not an issue, just the description of what the image is supposedly of. If someone specifically identifies the "physical phenomena", I have no objection to its re-introduction into the article. mdf 19:58, 4 April 2007 (UTC)

Yeah, I understand. How about just atmospheric phenomena? Nick Mks 20:01, 4 April 2007 (UTC)

Even that may be a bit vague, but it's certainly better than nothing. The person who knows best is probably the author of the image, User:Valdezlopez. I've left him a note. mdf 20:12, 4 April 2007 (UTC)

Under the heading of Observation is "The highest altitude of the Moon on a day varies and has nearly the same limits as the Sun. It also depends on season and lunar phase with the full moon being highest in winter." is this for the Northern Hemisphere, is this article written for Northern readers? — Preceding unsigned comment added by 220.233.208.191 (talk • contribs)

This statement is correct for both hemispheres, i.e. full Moon is highest in local winter. Nick Mks 13:36, 5 April 2007 (UTC)

I see the image of the Moon I removed yesterday has returned with a caption "lunar eclipse". Thank you, User:Valdezlopez. However, it pains me to make a few observations here. (a) the geometry of the shadow is wrong for an eclipse of the Moon. Compare the shape of the shadow with the animation currently at Lunar eclipse. (b) The red color of an eclipse is going to be on the inside of the curvature, and there is a noticeable gradient in color and intensity, features apparently absent in this image. And, most alarming of all, there was no lunar eclipse in 2006 May (see http://en.wikipedia.org/wiki/List_of_lunar_eclipses). mdf 20:53, 5 April 2007 (UTC)

I'll also note that according to the EXIF data within the image, it was collected at 2006-05-20T03:18:38. At that time, the Moon was almost exactly at third quarter. And indeed, but for the red color, this looks for all the world like a picuture of the Moon at third quarter, not in eclipse. mdf 20:57, 5 April 2007 (UTC)

I hadn't noticed that it had returned yet. Indeed, the caption is impossible. It think we better remove it, since the last talk at the FA is that there are too many pics. Nick Mks 16:39, 6 April 2007 (UTC)

Selenography

This word is currently moribund, if it was ever used at all in the way Wikipedia is currently using it. As I mentioned at the selenography talk page, it's arguably a neologism. I'd love to be bold and just change it to "lunar geography", if only to be consistent with "lunar geology" (used in-article). But one suspects resistance. mdf 19:27, 4 April 2007 (UTC)

If you know this, it's your call. I'm just the astrophysicist here, before yesterday I hadn't even heard the word. Nick Mks 19:54, 4 April 2007 (UTC)

I've been trying to find a "real" use of the word in the manner Wikipedia is doing, but have mainly drawn a blank. People use it, but not the "important people" (so to speak). Most of the good stuff on the subject is found by searching for "lunar geography". Hopefully, I'll be surprised. Just today, for example, I came across "selenophysics" for the first time (see http://www.iers.org/documents/publications/tn/tn34/tn34.pdf). I initially thought it was just some guy trying to be cute with "lunar geophysics" (~650 hits at google), but others have been using the word in the same way (~40 hits). mdf 20:26, 4 April 2007 (UTC)

Selenography was always understood to be the study of the physical features of the surface when I was studying many years ago. As for it being a neologism I would refer you to this library entry

Our Satellite: a Selenography Author: D'ORSAN, Dr. A. Le Vengeur Contributor: DE MORGAN, Augustus Mark : DE MORGAN Reference : 1824 (October 11,1862), 460 - at

http://www.soi.city.ac.uk/~asp/v2/titles/tget.cgi?1824.html@OurSatellite:aSelenography

Sorry about the length of the link but I could not use tinyurl for some reason. I think 1824 counts as not new, and I'm sure the phrase pre-dates that book by a good way. Its a shame people like to change lovely old words for no particular reason. PrivateWiddle 20:03, 14 May 2007 (UTC)

Moon News

One of the major benefits of wikipedia over other encyclopedias is the option for being current, and providing news - a place to revisit for updates. One of the most newsworthy items through the centuries has been the eclipses of the sun and moon. This news should be included in this site - based on relevance and interest:

Next Eclipse:

• 28 Aug 2007 - Total Lunar Eclipse

A total lunar eclipse will be visible over the Americas, the Pacific, eastern Asia, and Australasia.

(Saros 128, umbral mag. 1.481, max. eclipse 10:37 UT total: 09:52:00 UT to 11:22:45 UT)

Next Solar Eclipse:

• 11 Sep 2007 - Partial Solar Eclipse

A partial eclipse will be visible over southern South America, and parts of Antarctica.

(Saros 154, umbral mag. 0.749, max. eclipse 12:31 UT partial: 10:25:45 UT to 14:36:33 UT)

Next Total Solar Eclipse:

• 1 Aug 2008 - Total Solar Eclipse

The track -- 237 km wide at maximum -- begins in north Canada, passes near the North Pole, and into northern Russia. It then runs south-east into China. It is visible as a partial eclipse in Britain, though will not be dramatic. The maximum duration is 2 minutes 27 seconds, and the path width at maximum is 237 kilometers.

(Saros 126, umbral mag. 1.039, max. eclipse 10:21 UT total: 09:21:07 UT to 11:21:28 UT)

citations: http://sunearth.gsfc.nasa.gov/eclipse/OH/OH2007.html and for being user friendly http://www.hermit.org/eclipse/

Roo 7 April

Yeah, well, good point but a list like the one you added is not acceptable in a FA. I'll see to it. Nick Mks 12:16, 7 April 2007 (UTC)

Exploration suggestions

I think an important and interesting fact to place in the second intro paragraph would be how many people have landed/set foot on the moon, to date; I don't know where that figure is given, if it is anywhere on Wikipedia. That the six Apollo missions have been the only manned missions to the moon should also be given more prominence; I don't think Project Apollo states that clearly either. Cheers, Postdlf 22:07, 8 April 2007 (UTC)

Feel free to amend. Nick Mks 14:50, 9 April 2007 (UTC)

I took the liberty of removing a statement stating that the section of the article detailing the moon landings is based on "assumption" and "hard evidence suggests they were staged". The vast majority of the scientific community accepts the landings as fact. If someone wishes to pass off statements to the contrary as valid scientific discussion, perhaps it belongs in its own section "Controversy about the Apollo landings" or something to that effect- with actual citations to scientific evidence rather than a generalized, uncited vague statement such as the one that was here. I personally won't waste my time on starting such a section, however... spiffmedic 10:21, 2 June 2007 (EDT)

There is no conclusive evidence that any human being has ever set foot on the Moon. These sorts of myths and urban legends have no place in an encyclopedic article. 84.50.77.116 08:18, 28 August 2007 (UTC)

moon earth angular momentum and Moon's recession

Ok tell me if I’m way off the scent here but this is what how I’ve been thinking on this.

1.The Moon causes tides on Earth, and this big bump of seawater wants to stay facing the moon but is moved all the time to the West becoz of the Earth’s rotation on its axis. This “deforms” the Earth’s mass from an almost perfect sphere into one whose mass is slightly asymmetrical.

Almost. There is also a bulge on the side of the Earth facing away from the Moon. This is a result of the combination of the fact that this water is less attracted than the Earth itself and the (virtual) centrifugal force. This is the reason that you have high tide twice a day, not once. Nick Mks 18:33, 11 April 2007 (UTC)

2.The moon "feels” this asymmetry as if the Earth is slightly ahead of where it actually is, and this acts as a slingshot, making the Moon move faster.

3.The rate the Moon should be moving is governed by Newton’s Celestial Mechanics, which specify the orbit height of a Moon type - object as based on the masses of the objects and the speed at which the Moon was initially traveling.

4.The Moon moves faster than it should be based on these Laws, and is therefore kicked up continually into higher orbits. The Moon is actually spiraling upward.

(2) through (4) may be a bit plastic, but I guess it's a good way of visualising something that is actually quite abstract. Nick Mks 18:33, 11 April 2007 (UTC)

5.The Earth is losing angular momentum as a result of the friction of the tides which causes water to crash into continents. This is slowing the Earth down, and thus making the tides less energetic over time. In turn, this means that the “slingshot” factor in 2 above becomes weaker, and the Moon’s recession rate will slow down.

Correct. Nick Mks 18:33, 11 April 2007 (UTC)

6.This means that if you set up an electricity station working on tidal power, you are not only slowing the Earth down, you are slowing the Moon’s rate of recession down.

Correct. Nick Mks 18:33, 11 April 2007 (UTC)

Yes,

Myles here. Now that I've slept on it, I've got a question on this. Yes, you are slowing the Earth down if you generate electricity from the tides, but now I think that the Earth would have slowed down just as much even if that tidal plant had never been built. Reason: The tidal surge you used would have been stopped by friction anyway. You just exchanged one source of friction for another, and as this is a simple diversion, then there has been no change to the status quo. Correct? Myles325a 08:00, 12 April 2007 (UTC)

Of course. However, I'm not an engineer, but I can imagine power plants intentionally create more friction than you would normally have from water against water. Nick Mks 08:33, 12 April 2007 (UTC)

Myles here.Sure, but does the TOTAL friction the tide water encounters change, according to the terrain it traverses, or is it spread out for longer. Look at 3 scenarios: 1. the tide runs into a massive sea wall which stops it dead, 2. the tide runs on to a marshy plain like near the Everglades, or 3. there is a whole coastline of tidal generators. The 3 options take different times to stop the tide, but I am now thinking that the total work done by the tide must be the same. If that is true, we are not robbing the Earth of anything it would not have lost already. --Myles325a 23:16, 12 April 2007 (UTC)

Yes, eventually, when synchronisation is achieved, the total amout of energy lost will be the same, it will just go faster. But on a human timescale, this seems to be more. Nick Mks 09:12, 13 April 2007 (UTC)

Myles here. You mean the synchronization when the Earth faces the Moon all the time? Will that ever happen? And would that mean the Earth's day then would be about a month long? My question was really if EACH INDIVIDUAL TIDE expends the same energy regardless of whether it is stopped suddenly or flows out over a marsh? After all, in each scenario, each drop of water is brought to a full stop, it's just that if you have a sea wall that stop is sudden. --Myles325a 05:50, 14 April 2007 (UTC)

Yes, eventually this would happen. However, as I've said, I don't think the solar system will survive long enough for that. And yes, a month would be equal to a day then (but none of them would last the number of seconds it does now). I'm unsure about the friction thing, but since the water always goes the same way (it does not stop and turn back) I do believe it's possible to lose more energy than it does naturally. Nick Mks 18:33, 14 April 2007 (UTC)

7.As well as this, as the Moon moves away, the tidal effects will become less pronounced anyway because such effects depend not only on the gravitational strength of the Moon but the differential of its effect. In other words, if the Moon’s gravitational attraction were to be spread more evenly over the Earth’s surface, then the tidal effects would become weaker. That is, presumably why the Sun’s tidal effects are so weak. The Sun is much more massive than the Moon, but its gravity effects are less focused on any particular area on Earth. As the Moon moves away from us, its tidal effects will also become less focused and thefore less intense.

Well, quite close. Gravity is a force that declines with R², so if you're twice as far, you have four times less attraction. I don't see though how this relates to spreading the force evenly over the surface (which obviously always is the case). Nick Mks 18:33, 11 April 2007 (UTC)

8.The Moon faces the Earth because over time, the Earth’s tidal effects on the Moon caused the Moon to slow down and come into synch with the Earth, by similar mechanism as in all above. Many satellites in Solar System are similarly affected.

Correct. This is not yet total synchronisation though. This also requires the revolving period to be equal to the rotation period of the other body. So eventually you'll have 1 day = 1 month. Once Earth synchronises with the Sun as well, you'll have 1 day = 1 month = 1 year. However, you'd need many times the expected lifetime of the universe for that, while we only have five billion years left. Nick Mks 18:33, 11 April 2007 (UTC)

9.Becoz the Moon now always faces us, Earth senses that the Moon is correctly positioned, whereas the Moon senses that the Earth is slightly ahead of where it really is. Had the Moon still been rotating on its axis at its original speed, the rate of the Moon’s recession would now be higher. Moon’s recession rate decreased as its orbit around Earth as its “day” came into synch with its “year”. That is, the duration of one spin on its axis became the same as the duration of one round on it orbit.

I'm not so sure about this. The facts are correct, but I don't see why a faster rotating (rigid) Moon would recess faster. Nick Mks 18:33, 11 April 2007 (UTC)

10.The whole business of the “conservation of angular momentum” as the reason why the Moon is moving away is confused and misleading. If the Earth and Moon had been perfect spheres of an inelastic substance, then there would BE NO TRANSFER of angular momentum. In such a scenario, you could rev up the Earth’s rotation on its axis to a million per hour, and it would have no affect on the Moon. The whole mechanism is caused by the tides, nothing more or less. It is the deformation of the material changing their centers of gravity that give rise to the effect. This last is what I really want some feedback on. I had always wandered how it was possible for the Moon to somehow sense that the Earth was slowing down, and adjust itself accordingly in order for the equations governing “preservation of angular momentum” to work out.

Correct. The reason is that in a system of perfect spheres of an inelastic substance you would need an external force to rev up the Earth’s rotation on its axis to a million per hour. There, you have an external source (or drain) of angular momentum, so it's no longer conserved in the Earth-Moon system. Nick Mks 18:33, 11 April 2007 (UTC)

Myles325a 14:18, 11 April 2007 (UTC)

Now this is all good and well, but what of this do you want to put in the article? I do find the current content on this pretty good, it's informative and yet understandable. Nick Mks 18:33, 11 April 2007 (UTC)

Thanks a lot for that, Nick. It mainly confirms what I had kinda nutted out. It means that the Moon's recession will stop, or at least asymptotically approach a limit, and it should be possible to calculate when that should happen. So we've saved the Moon, and I've managed to use the word "asymptotically" for the first time. Yippee! You're right, it probably doesn't belong in this article, but it does belong somewhere. Perhaps I should donate it to Conservapedia? They seem to have some problems with Moon recession. Also see my new comment on point 6 above. Myles325a 07:53, 12 April 2007 (UTC)

I'm afraid that would get you a lifetime block over there. I'm not so sure whether we saved the Moon, the timescales involved here are enormous. It's quite possible that the Moon is already lost by then (theoretically, Earth's gravitational field extends to infinity, but at some point the noise from other bodies gets larger). Nick Mks 08:33, 12 April 2007 (UTC)

11. Myles back. Some ideas I've had in my head. Impact events on the moon should have been affected by change in moon's spin over time. Far side impacts should be more numerous because near side impacts have to pass the gauntlet of Earth which would clean up a lot of them, and send some into orbit. Thus, stat survey of dispersion of impacts on Earth should give indication of when Moon’s orbit synchronized with its rotation, thus giving insight into age. Same idea for statistical survey of “leading edge” impacts, as the leading edge has changed over time. Do you think that any of these could bear fruit? (oh and see another comment on point 6 above0 Myles325a 05:50, 14 April 2007 (UTC)

The Moon's interaction with Earth acts only in the disipation of Moon's energy, so Moon must fall down into our Earth (because of a simpe gravitational force). Moon can go up in speed only by introducing other forces into this system (not terrestrial, and Sun is guilty for that if this is true). So in this article is written a pure nonsense.

Another nonsense is that Moon always faces Earth because of interaction between them. In fact, we are lucky that Sun and Moon have similar spatial angles which are guilty for such Moon's behaviour (as well as eclipses) — Preceding unsigned comment added by 82.21.144.216 (talk • contribs)

I'm not sure what exactly you are trying to say, but you seem to indicate that you believe the Sun to be the reason for Moon recession and synchronisation. I can assure you that this is not the case. Nick Mks 18:57, 17 April 2007 (UTC)

"The Moon's interaction with Earth acts only in the disipation of Moon's energy" - this is not true. The Earth/Moon interaction causes a transfer of angular momentum and energy from the Earth to the Moon. "Moon can go up in speed only by introducing other forces into this system" is therefore not true.

"Another nonsense is that Moon always faces Earth because of interaction between them" - this is not nonsense, it's the real reason. "we are lucky that Sun and Moon have similar spatial angles which are guilty for such Moon's behaviour" - no, the Moon would show the same face to Earth even in the absence of the Sun. There are other instances of tidal locking in the solar system where the Sun and the moon in question do not have similar angular diameters as seen from the planet (see Tidal_locking). Occultations 14:47, 18 April 2007 (UTC)

I think the second paragraph of the article on the moon is incorrect on the issue of the moon's recession. It states:

"The energy dissipated in generating tides is directly responsible for the reduction in potential energy in the Moon-Earth orbit around the barycentre, resulting in a 3.8 cm yearly increase in the distance between the two bodies"

The recession of the moon away from the earth increases the gravitational potential energy of the system. This increase in GPE is offset by a decrease in the rotational energy of the earth. Gordion 10:32, 21 August 2007 (UTC)

I made a note of this point on the 11th of June. Besselfunctions 04:11, 28 August 2007 (UTC)

I agree that the statement about potential energy decrease is wrong. I think the confusion stems from the counterintuitive notion that an increase in distance between two masses means an increase in gravitational potential energy. However, the statement did not specify the type of energy described as potential. Also, the author/authors may have meant to say "decrease in kinetic energy." Either way, I think the statement needs subtle rewording.--146.145.125.131 17:47, 28 August 2007 (UTC)

I haven't read through this entire section (sorry, too busy!) But I have worked out a considerably longer explanation that I think doesn't fly in the face of the physics. I was going to put it in then realised I hadn't incorporated the recessionary figure of 3.6 cm / [time unit]. I'm not going back to rework it, but here's my contribution if anyone else would like to.

• Rotational energy is converted to heat by the frictional effects of the tides. This energy radiates away from the system. The result of this is that the kinetic energy of rotation is decreased, making the orbital period longer. Paradoxically, to balance the lower centripetal force of the slower rotation, the earth-moon distance increases, raising the potential energy. The net effects are thus: loss of energy from the system through radiated heat; lower kinetic energy through slower movement around the barycentre, but increased potential energy through greater earth-moon separation.

King Hildebrand 18:53, 29 August 2007 (UTC)

Eternal light

From images taken by the Clementine mission, it appears that four mountainous regions on the rim of the 73-km-wide Peary crater at the Moon's north pole remain illuminated for the entire lunar day, at least during the hemisphere's summer season. These peaks of eternal light are possible because of the Moon's extremely small axial tilt to the ecliptic plane.

The text above contains an inconsistency. For the peaks to be illuminated for the entire day during summer, a large axial tilt is not prohibitive. Compare earth: large axial tilt and midnight sun. What an extremely small axial tilt might enable however, are peaks that are illuminated during the entire lunar year. Also luna orbits very close to the ecliptic, so the eternally lit areas would have to be very horizontal. Shinobu 15:48, 14 April 2007 (UTC)

Good point. I looked it up and it should be really eternal (except during eclipses). Nick Mks 18:38, 14 April 2007 (UTC)

Earth's New Temporary Moon

Someone with experience at editing pages should add this. It is the only known natural moon besides 'the Moon'. It's identified as "6R10DB9" see [2]. See also [3] and [4]. An article from Sky & Telescope [5]--Daveonwiki 18:00, 19 April 2007 (UTC)

Cool, but not appropriate in this article I'd say. Nick Mks 18:53, 19 April 2007 (UTC)

Only celestial body orbited...

The first sentence of the second parargraph states that the Moon is the only celestial body that humans have orbited except for the Earth. What about the Sun? The centre of the Milky Way? -- Rmrfstar 23:08, 19 April 2007 (UTC)

Hm, can't say that you're wrong. Any suggestions on how to rephrase? Nick Mks 09:15, 21 April 2007 (UTC)

Well I don't think it's that significant of a fact. I'd take it out and leave that it's the only celestial body that we've landed on. -- Rmrfstar 12:43, 21 April 2007 (UTC)

or add "in spacecraft". I assume it's there to make it explicit that although probes have been to other planets, men have not. Sophia 13:48, 21 April 2007 (UTC)

Yes, but while you are orbiting the Earth in a spacecraft, you're also orbiting the Sun in your spacecraft. So that doesn't really solve the problem. I guess I'll take it out. Nick Mks 14:47, 21 April 2007 (UTC)

Direction of orbit

The article implies, but does not state directly, which way the Moon orbits the Earth - anticlockwise, as viewed looking down on the North Pole of the Earth, same as the Earth itself rotates. It might be better to state this explicitly.148.197.5.19 09:22, 20 April 2007 (UTC)

Why not, go ahead. Nick Mks 09:16, 21 April 2007 (UTC)

Limb?

What is a limb of the Moon? I saw the word used in Lohrmann (crater) and it is in this article too, but not explained. Thanks. Itsmejudith 11:39, 23 April 2007 (UTC)

See limb for the answer. Urhixidur 14:43, 24 April 2007 (UTC)

Thanks very much for your answer and for making the link in the article. If I've got it right the limb is the great circle that divides the near side from the far side. I don't quite see how the term would relate to other celestial bodies, unless it is always defined by their positions relative to Earth. A bit more clarification in the relevant articles might be called for. Itsmejudith 15:01, 24 April 2007 (UTC)

As a common amateur astronomer I have always understood it to mean the visible/apparent edge of the Moon and those areas close to it. This has more currency because the Moon presents the same face to us all the time so you can simply say that such and such a feature is on the southern limb. PrivateWiddle 18:45, 14 May 2007 (UTC)

70.68.70.186 15:13, 4 July 2007 (UTC) I saw a 3/4 full Moon on July 4th from the northern hemisphere at 6:00 AM, with the sun a little above the horizon. But the lit surface of the Moon does not point at the sun; it's as if the sun ought to be much higher in the sky. How can that be?

Correct, or badly written?

"allow a total of about 59 per cent of the lunar surface to be visible from Earth at one time or another"

As it currently reads, this would mean that you can see 59 percent of the moon at any given instant. Is this correct or should it have been written as; "allow a total of about 59 percent of the lunar surface to be viewed from Earth."

I skimmed through the article looking for shape descriptions other then oblateness, as this wouldn't change the maximum permissible view at a single instant, but didn't find anything.

--Charlesburg 03:30, 26 April 2007 (UTC)

Your rephrased interpretation is correct, however I don't see the problem. I think the at one time or another does the trick. Nick Mks 17:16, 26 April 2007 (UTC)

So at any given point in time I can look at the moon and see 59 percent of the surface even though it's a slightly squashed sphere and that should be impossible? I went and read the NASA article quoted, it has indeed been misquoted. You can not instantaneously see 59 percent of the moon as the quoted sentence reads, the original quote is "Because of libration, about 59 percent of the lunar surface is visible from Earth.".

I would suggest either correcting the sentence to the original quote, or modifying it to remove time.

Charlesburg 01:44, 1 May 2007 (UTC)

Yes, but the sentence in the article does say at one time or another and not at any given time. I really don't see the problem, but if you want to change the wording, go ahead... Nick Mks 09:16, 1 May 2007 (UTC)

Luna vs. Moon (One More Time!)

Keraunos adjusted the article to read that the name is "Luna", not "Moon". This matter has been discussed several times in the past (see the archives 1, 2 and, in particular, 4), and the consensus has always been a firm bias to "Moon". I have reverted this change for now, and invite Keraunos to produce the references that back the assertions he wishes to place in this article. (In my opinion, reflected by the previous discussion, he has a very steep slope to climb: to my knowledge, there is no significant body of English scientific literature on the Moon that refers to it as "Luna", and outside of some Robert Heinlein (and others) fiction, the occurrence in common English is far below the noise floor.) mdf 15:46, 9 May 2007 (UTC)

Agreed. --Ckatz^chat_spy 18:09, 9 May 2007 (UTC)

Concur. Shimgray | talk | 18:22, 9 May 2007 (UTC)

Agree. Nick Mks 06:00, 10 May 2007 (UTC)

I have noted this practice on some astronomy blogs and it seems strange to most people who have commented on it elsewhere. Of course, it comes from the Roman goddess Luna, and if you are speaking a Romance language it is perfectly correct (ie: La Luna in Spanish). But it has never been used in English, even as a rare alternative form. English draws this word from the Germanic languages which formed the basis of Saxon Old English, hence the German Montag, for Monday. I have a stack of Astronomy books and magazines going back 25 years, and had never heard of this until very recently. With all due respect to Keraunos, I really think that this type of thing needs to be stopped because it will confuse readers. I might also mention that the next fad that has started on some telescope review blogs and forums is to say Sol instead of Sun. PrivateWiddle 17:48, 14 May 2007 (UTC)

Agree - Every other planet's natural satellite has a name, like Jupiter's Io and Europa. Our satalite has Luna as it's name. --James W. 13:20, 21 May 2007 (UTC)

Here is a link to an online dictionary [6]. Please search on "moon" and "luna". Lunokhod 22:11, 23 May 2007 (UTC)

Our moon does have a name. Our moon's name is Moon. Astroguy2 19:50, 3 June 2007 (UTC)

It's a strange thing. I would say Earth's only visible moon, to the naked eye that is, is un-named. Many would argue it's called Luna, but that's the Latin for the word moon. And as "moon" is given as a word for NS's (Natural Satellites) one could conclude "The Moon" is nameless. But, "Moon" could be the name for our NS, as it was given before we knew of the other NS's orbiting other planets. So using moon as a word for NS's could be incorrect.

See below as the other orbiting bodies are satellites and the moon may be a double planet, perhaps it does have a name... moon.

"Luna" is certainly strictly a poetical name, but the word "moon" should not be capitalized any more than "sun" or "universe" should be (but which WP does). It is not an actual name and therefore not a proper noun and is firmly established by publishers as uncapped. I'd like to know what authority Wikipedians are appealing to on this or if they are just making it up as they go along like a lot of other editorial conventions (like capitalizing animal terms and political titles). What's the name of our planet's atmosphere? "the Atmosphere"? How about our water table? "the Water Table"? --Tysto 16:22, 9 October 2007 (UTC)

IAU Website: Spelling of Names of Astronomical Objects --Ckatz^chat_spy 05:34, 10 October 2007 (UTC)

This is obviously a semantic problem. By convention, if “Moon” is capitalized it is a Proper Noun or name of an explicit thing, and “moon” is a generic or common noun referring to all such satellites . The reason moon, sun and water table are not capitalized more frequently is that in that in most contexts writers and readers will be ignoring the suns, moons and water tables of other planets, so it is regarded as pedantic to insist on capitalization. In brief, capitalization is employed where one needs to indicate that the item in question is a particular thing and not a category of things. One could argue that “opera house” should be capitalized because it signifies a particular sort of house, but if we were to take that line, we would end up capitalizing virtually all nouns, like the Germans do. Luna is a lovely and poetic name, but it is not widely known, and as such to include it would confuse readers, which is not the purpose of a general encyclopaedia. Most people around the world are not science fiction devotees or particularly interested in astronomy. To them, the Moon is that glowing orb seen at night, and it is of little consequence to them that is an example of other such moons around unseen planets. Myles325a 06:45, 10 October 2007 (UTC)

My opinion (which I one day believed to be the general scientific view, but I got lost along the way) is the following: a non-manmade object that revolves around a planet is called a natural satellite. Planet Earth (capitalised, since there is only one) has one natural satellite: (the) Moon. Stricltly speaking, there is no other object in the universe called Moon or moon. However, many people choose to use moon as a synonym for natural satellite. Nick Mks 07:16, 10 October 2007 (UTC)

double planet

The section "5 Orbit and relationship to Earth" discusses the double planet issue is a dismisive way, mentioning only why it may not be a double planet, without any explanation of why the controversy exists. This is unfair.

The moon is gravitationally attracted to the sun more than it is attracted to the earth. The moon is drifting away from the earth every year.

There is no mention of Issac Asimov's artile on "why is the moon so far out there" A link to the wikipedia double planet should be provided. 198.103.184.76 15:53, 28 August 2007 (UTC)c. priest198.103.184.76 15:53, 28 August 2007 (UTC)

The Moon's Recession Rate

The introduction cites reference [2] as stating the recession rate is 3.8 cm/yr, and the section entitled "Orbit and relationship to Earth" cited reference [41] as stating the recession rate is 4 metres per century. Since both references have the 3.8 number (and one is more specific--3.84) and not the 4 number, I changed "4 m" to "3.8 m" for the sake of internal consistency.

Also, since both reference [2] and [41] were only used for the recession information, I decided to eliminate them and replace them with a better reference, so now [2] and [41] are the same. Is there a way to change that or does Wikipedia always number references sequentially even if they are the same source? In other words, is it just the way Wikipedia works that one could have a reference section with the same reference listed 50 times? Redhookesb 06:43, 31 May 2007 (UTC)

Doesn't the potential energy of the Moon-Earth system increase as they grow farther apart? What is this reduction addressing in the lead? Either way it's confusing. Besselfunctions 06:54, 11 June 2007 (UTC)

I think Besselfunctions is right here. The movement of the moon away from the earth results in an increase in gravitaional potential energy. The loss of the earths rotational energy is the compensating factor. Effectively the distortion to the shape of the earth induced by the moon's tidal forces results in a net torque on the moon about the barycentre. This torque is in the direction of the moons rotation, so it results in an increase in the moon's orbital energy, which results in a larger orbit.Gordion 13:42, 21 August 2007 (UTC)

Helium3

The article is missing a reference to Helium3...

Some background info on He3 in the moon can be found on the Horizon pages of the bbc: http://www.bbc.co.uk/sn/tvradio/programmes/horizon/broadband/tx/moonsale/

Our photo is correct, lunar eclipse does not show curve of Earth.

The first lunar eclipse I saw as an adult, I was expecting to see the curve of the Earth move across the Moon, and that simply did not happen. The whole thing was much more shadowy. And, on thinking it over, it occurred to me, if we’re going to expect earlier peoples to have figured out that the Earth was a sphere, it was not going to be from this line of evidence! (And yes, the Moon was kind of reddish or orangish, but I wouldn’t exactly call it blood red.)

Please look at our picture of the March ’07 lunar eclipse, there’s not really much of a curve at all.

Now, our article does not claim a curve, but this might be enough of a common misconception to be worth including and discussing. And we might also want to jazz up our “Human understanding” section. I mean, was Anaxagoras really the first to have a early scientific understanding? How about the Hindus and/or the Native Americans? Or the people who built Stonehenge in England, yeah, they may have believed a bunch of mystical stuff, but they may have also had a pretty good understanding of how Sun, Earth, and Moon interacted. FriendlyRiverOtter 09:42, 11 June 2007 (UTC)

6R10DB9

This is just a "heads-up" to keep tabs on 6R10DB9, a temporary satellite of Earth [7] -- which if it proves to be a small asteroid (rather than moon-mission junk) may warrant at least a footnote in this article. — Eoghanacht ^talk 15:30, 25 June 2007 (UTC)

Gravity

The formatting on the gravity entry in the table on the right is... tricky. At first glance, it looks like there is no entry for gravity and the Equatorial Surface is its own category. As this is not directly editable, I could not fix it myself. Perhaps the table needs to be widened? Superdupergc 20:16, 26 June 2007 (UTC)

Moon in general

I have a few questions:Shaunthinks93 18:49, 1 July 2007 (UTC) 1. If craters are caused by asteroids or comets, how can there be craters on the side of the moon that is always facing the Earth?

2. Why when scanners, monitors, detectors are dropped on to the moon, does it clang as though being struck like a bell, this must mean it is hollow. On this website there is a section that shows the layers of the moon, how can there be all those layers if the moon is hollow?

3. This isnt a question, but, if the moon is actually a spaceship, and we are an expiriment, a kind of TV show, if you like, this would explain why there are craters on the front of the Moon: these are created when that spaceship was travelling through the universe to get here. also the Hollow clanging would be caused by the inside of the spaceship, where it is controlledand the aliens habitate.

People always think of aliens from other planets, solar systems, and galaxies, but never think of the one thing that is right next to us, always there, always patrolling, checking and we never even thought about that possibility... So just think about it, all the possibilities that there could be of the moon.

Shaunthinks93 18:49, 1 July 2007 (UTC)shaunthinks93

1. There are fewer craters on the side that faces the Earth, but it's not like the Earth is so large as to completely block all possible trajectories from space into the Moon's face. Many, but not nearly all, incident meteors/asteroids/&c. are blocked by the Earth.

2. They don't. They don't make any sound at all-- there is no atmosphere on the Moon to carry sound.

3. Did you forget to take your Risperdal? siafu 17:01, 2 July 2007 (UTC)

Some additional comments on points 1,2,3 above.

1.Some theories regard Jupiter as an important sentry of the outer solar system, in that it could have mopped up asteroids that would otherwise have collided with Earth. The Moon has been said to do the same thing with respect to Earth, and the Earth with the Moon. The effect of shepherding asteroids away from the near side of the Moon need not be dependant just on the bulk of the Earth intercepting asteroids that would otherwise have collided with the Moon. The Earth would interfere with the orbits of nearby asteroids, sending some of them off into deep space, just as Jupiter is said to have done with respect to the inner solar system. I had the notion that you could estimate when the Moon had adopted its current posture by mapping asteroid impacts on the near and far sides and comparing them. Theoretically, this might have given a better determination of the Moon’s age. I sent this to the Geology Dept at Harvard, who were interested enough to reply, but opined that the distribution figures would not be fine enough to make estimations statistically interesting.

2 Also had the notion that some such statistical survey on extraneous matter picked up by the leading edge of a satellite as it moves thru space. It ploughs through interplanetwry dust and stuff, and so there should be more of this on the leading edge. If the leading edge has changed over time, then distribution of such matter will also have changed, thus giving possible way of estimating when such changes of direction in orientation occured. (Btw, this is where I think there is a common confusion between "limb" and "leading edge".)

3.The Moon is airless and therefore there is no atmospheric sound, but sound can pass thru the mass of the Moon itself. I read somewhere that an impact on the Moon, possibly human-engineered had it ringing like a bell for months. Any one rem this? Of course Moon could be a hollowed out Death Star, and we could be hearing the engines etc of such a device.

4.Moon as alien space ship might explain why we see it as EXACTLY covering the Sun during solar eclipse, a phenomenon which otherwise has no scientific explanation.Myles325a 05:28, 9 July 2007 (UTC)

COST OF EXPLORATION How much would a privately funded moon mission cost and who are the likely backers —Preceding unsigned comment added by 69.125.110.223 (talk) 17:20, August 30, 2007 (UTC)

Why one side always faces the Earth?

I find a different answer from what our article says, and an answer from a seemingly good website, and one that seemingly makes sense. “This synchronous rotation is caused by an unsymmetrical distribution of mass in the Moon, which has allowed Earth's gravity to keep one lunar hemisphere permanently turned toward Earth” [8] .

Our article says, “Early in the Moon's history, its rotation slowed and became locked in this configuration as a result of frictional effects associated with tidal deformations caused by the Earth.[6]”

Now, perhaps both could be contributing causes. Please help with this if you can. FriendlyRiverOtter 19:08, 2 July 2007 (UTC)

The first one is not exactly correct; tidal locking does not require an asymmetric distribution of mass. The moon may have such an asymmetric distribution, but this also happens as a result of tidal locking and need not be a cause. siafu 21:36, 2 July 2007 (UTC)

And that might explain why other satellites in the solar system have this same one-side-facing-only relation to their planet. Next question, why is it 59% of the moon that we can see? FriendlyRiverOtter 03:35, 19 July 2007 (UTC)

WILL the moon get lop sided over time? due to centrifugal force — Preceding unsigned comment added by 69.125.110.223 (talk • contribs) Conny (UTC)

The material on the far side experiencing greater "slinging"? Maybe. I can kind of see that as a possibility. And since one side is always the far side, maybe over time there is a cummulative effect. And I am learning that many (most?) astronomical items are not perfectly symmetrical. FriendlyRiverOtter 08:23, 14 September 2007 (UTC)

The moon isn't exactly in tidal lock: it librates around the equilibrium, torqued by forces other than the Earth's point-mass potential. The moon is also not symmetric in its shape, as a result of the tidal forcing. Hence we can see 59% of the surface. For a better discussion, see tidal locking or any standard intro. astronomy text. Further discussion here is not appropriate. Michaelbusch 08:27, 14 September 2007 (UTC)

Oh, Michael. Why? Many of our articles end up not really explaining anything, not really teaching anything, not really describing anything. Our articles mainly just mention things and refer elsewhere. We seem to have rules that stand in the way of narrative flow and natural human language.

Exactly what you explained about libration would be good to include in the article itself! And as long as we keep our article divided into sections we need not worry about length, for people can read what they're interested in, and not read what they're not.

I should learn something from reading a wikipedia article, and often I do not. FriendlyRiverOtter 17:14, 14 September 2007 (UTC)

Equatorial circumference

If the equatorial radius is correct at 1,738.14 km, wouldn't the equatorial circumference be 10,921 km, not 10,916 km? 10,916 would appear to be based on a 1,737.4 figure for the equatorial circumference which various references give. I know the moon's not a perfect geometric shape, so I can't assume that 2πr necessarily holds in this case, but the source for 10,916 km does use the 1,737.4 figure (×πr = 10,916.4)...--Father Goose 07:51, 13 July 2007 (UTC)

The Earth from The Moon.

Some people are consistent to believe that "The Great Wall of China" is the only man-made object visible from The Moon. However, if I, or you were to be standing on the moon right now, and took a glance over to where Earth is, you would just about be able to make out the continents.

The moon is over 400,000 km away, seeing anything man-made on the earth, with the naked eye, would be almost impossible (but the object would have to be rather large, as in, starting on Earth, then leaving it. If such a thing could be made, think of an elevator "into space") Many confuse it with 'space'. 'Space' starts about 100km from the surface, and quite a lot can be seen from here. Things like motorways (highways), ships on the sea, cities and even a few individual buildings. Of corase the further out into space you go, the less you'll be able to see.Jamiepgs 15:56, 16 July 2007 (UTC)

Jamie please sign your posts by typing ~~~~ and could you explain what your point is? "Space" is a pretty undefined term as even 100km up you are still in the heliosphere. Each area of "space" tends to have its own technical term such as interstellar medium . As for what is visible from the moon - I've never actually checked it but it is generally accepted that the great wall of china is the only man made object visible from there. The point is not what can be seen from "space" but what is seen from the moon as that is what this article is about. Talk pages are only here to discuss potential changes to the article and should not be used to float vague ideas. Sophia 15:42, 16 July 2007 (UTC)

OK, then I suggest that this could be added...

Although it's accepted, it doesn't make it any less false. Claiming that The Great Wall of China is the only man-made object on Earth, visible from the moon with the naked eye would be making a false statement. [9] The point I was making was that people confuse it with what you can see from Space, as in its early reaches from our surface it is visible. Jamiepgs 15:56, 16 July 2007 (UTC)

I see now what you are saying and you are correct that it is false - this is a better source [10] for that fact. The point that you are making about confusing visability distances doesn't really belong here and I'm scratching my head to think where it would go. This would count as WP:Trivia and I'm not sure it really adds anything. The moon is a fascinating structure who's formation and composition are not really understood and these are the areas this article focuses on. The moon dust was an interesting fact as it enabled us to relate it to everyday things making the facts more accessible but this I feel does not improve the article. Sorry to be so negative and don't let it put you off making suggestions. You are doing the absolutely right thing by discussing this here and suggesting changes so we can all chip in. Sophia 17:06, 16 July 2007 (UTC)

At night, could you see the lights of large cities, or the burning flares of natural gas fields (if that practice is still used)? FriendlyRiverOtter 22:49, 13 September 2007 (UTC)

Etymology

I haven't been here in a while, and was surprised to see that there is now a section "Etymology". While this might help clarify these idiotic Luna-Moon discussions, the description appears to be incorrect. In particular, is it not true that the generic name "moon" is based upon the proper name "Moon" of Earth's natural satellite? Wasn't the Moon discovered and named before the other "moons" of our solar system? When people gave the name "Moon" to our natural satellite, did they do so with the knowledge that other "moons" existed, and hence that the name was generic and not proper?

Thus, I propose changing this sentence

The Moon has no formal English name, although it is occasionally called Luna (Latin for "moon") to distinguish it from the generic "moon" (referring to any of the various natural satellites of other planets).

to (or something similar)

The proper english name of Earth's natural satellite is the Moon, though it is occasionally called Luna (Latin for "moon"). The name Luna has never been formally recognized by any international organization, and its use in the popular and scientific vernacular is extremely rare. The generic word "moon", which refers to any of the various natural satellites of other planets, is derived from the name of Earth's only natural satellite. The confusion between the proper noun Moon (which is sometimes, though not always, captitalized) and the generic word moon has led some to argue that the Earth's natural satellite has no official english name. Lunokhod 10:40, 17 August 2007 (UTC)

Yeah, that section needed work. I took a hack at it.--Father Goose 19:30, 17 August 2007 (UTC)

Thanks for doing that. I've tweaked it a bit, primarily to move the third sentence into first place for a more formal definition. --Ckatz^chat_spy 05:44, 18 August 2007 (UTC)

I agree entirely. I'm also removing the Latin name in brackets in the opening sentence, because this is an English-language dictionary and the names of the Moon in the thousands of other human languages are irrelevant. Luna is discussed further down the article, and that's fine. But it has no priority over any other non-English name. -- JackofOz 06:31, 7 September 2007 (UTC)

I've reverted that change - "Luna", while not the English name, does get used frequently and a mention in the lead is relevant and justifiable (as with "Sol" at Sun). In this case, Latin does take priority over other languages as "Luna" is directly related to numerous English words ("lunar" etc.), many of which are used in this article. --Ckatz^chat_spy 08:10, 7 September 2007 (UTC)

I'm still not happy with that. Just because we mention Sol on the Sun's page does not, of itself, justify this. If Luna is used frequently, we should explain that use - not just say that the Latin name for the Moon is Luna, as if that bald fact was notable. It currently reads as if English-speakers are also Latin-speakers, who would obviously want to know this information. This is like the article for "Table" starting out with "A Table (Latin: mensa) is a piece of furniture that ... ". -- JackofOz 08:43, 7 September 2007 (UTC)

I see the sense of both arguments but more strongly agree with removing Luna in the first sentence. However, given the tiny amount of real estate we're talking about here, this threatens to go into WP:LAME.--Father Goose 09:23, 7 September 2007 (UTC)

Main page

oh my gosh, how did all those linked solo years get by FAC[11]? And there are month-year combos incorrectly linked as well. Solo years need not be linked, per WP:CONTEXT, WP:MOSLINK. Delinking them all will take forever; can someone help? They're even linked in the refs. Also, there are See also templates at the bottom of sections; per WP:LAYOUT they should be at the top. And portals belong in See also, per WP:LAYOUT. Also, there are spaced emdashes throughout the text, against WP:DASH. Normally I run through and correct these things before mainpage, but there's more work here than I'm accustomed to. SandyGeorgia (Talk) 22:21, 17 August 2007 (UTC)

Wow, I thought main page featured articles were particularly better than the others, and could at least follow style guidelines. Fault is the person who selected this to be on the main page. ~ UBeR 01:57, 28 August 2007 (UTC)

The selection may have been event-based--at the moment, as I write this, a lunar eclipse is occuring literally right outside my front door. --JB Adder | Talk 10:54, 28 August 2007 (UTC)

This article now contains two fact tags as well. - Face 16:34, 28 August 2007 (UTC)

eclipse section

i have taken this part out from eclipse section as that information is irrelvant to moon The next solar eclipse takes place on September 11, 2007, visible from southern South America and parts of Antarctica.The next total solar eclipse, on August 1, 2008, will have a path of totality beginning in northern Canada and passing through Russia and China. if i have done wrong I am sorry please put it back

Information such as this quickly becomes outdated and frivolous. You were right to remove it. Encyclopedias should take into consideration the historical context of what they're writing, rather than focus on non-important, albeit recent, events. ~ UBeR 01:59, 28 August 2007 (UTC)

I agree with UBeR that such temporal information goes out of date quickly. However, Wikipedia is dynamic enough to replace it with updated information when appropriate. To say that solar eclipses have nothing to do with the moon is like saying your reflection has nothing to do with the mirror - true in its way, but if it weren't for the mirror the reflection wouldn't exist! As to whether the info should be included, I'm slightly in favour of putting it back. --King Hildebrand 19:14, 29 August 2007 (UTC)

Good work getting this to the front page

Nice work folks :) Kidshare 07:37, 28 August 2007 (UTC)

I won't edit the article since it is on the front page, but shouldn't "...Apollo program has achieved the first (and only) manned missions to date..." read "...Apollo program has achieved the first (and to date, only) manned missions...", or similar. As it is, it implies that we may one day discover that the Apollo missions were not the first manned missions. I enjoy a good conspiracy theory, but no need to codify them in a reference work. Travis Garris 17:29, 28 August 2007 (UTC)

Travis's modification allows for humanity's return to the moon, but I don't see how either wording implies or fails to imply that the Apollos didn't land there. What am I missing?--King Hildebrand 19:09, 29 August 2007 (UTC)

• I particularly liked how the article was on the front page on the day of a lunar eclipse here in New Zealand.Lisiate 22:54, 28 August 2007 (UTC)

Errrm - unlike solar eclipses, lunar eclipses are visible wherever the moon is above the horizon - a whole hemisphere at a time. NZ was not uniquly blessed on this occasion. The moon is in the earth's shadow wherever you view it from.--King Hildebrand 19:09, 29 August 2007 (UTC)

Green cheese

How how in the world did the whole "moon is made of green cheese" saying start? --24.249.108.133 06:25, 29 August 2007 (UTC)

Well, it is. Didn't the scientist go to the Moon and check that? Winston.PL 14:07, 2 October 2007 (UTC)

Now that is a nice question.--Father Goose 07:16, 29 August 2007 (UTC)

Centripetal tides

It's not the centripetal force that generates tides. It's the gravitational differential between the centre of the earth or moon and its surface. The side of the earth facing the moon is pulled more strongly than the centre, causing a hump in the water on that side. Less obviously, the side away from the moon is pulled less strongly than the centre, so the water is "left behind" as the body of the earth is pulled out from underneath. The effect would exist in the absense of rotation. A similar tidal effect is felt on the moon, which is:

• greater due to the stronger gravity of the earth
• smaller because of the smaller radius of the moon, and
• less obvious because the moon has no easily deformable masses of liquid on its surface.

--King Hildebrand 19:01, 29 August 2007 (UTC)

Newton's well known explanation of the tides would only be valid in the absense of continents, as mentioned in the article on the physics of tides. In fact the tidal range in the middle of oceans is very small, and is only large on continental shelves. This is explained in R E Craig's book Marine Physics. It is more useful to think of the oceans as odd shaped, interlinked bowls of water, the tides being caused by the diurnal wobbling of the bowls and the effects of gravity on the water in the bowls.

As Craig explains, the resultant of solar & lunar gravity pulls the oceans horizontally, contributing to the resonant waves that cause the oceans to slosh about in their basins. The vertical effect (i.e. "the hump") is negligible.

While the WP article on tides does not say this in so many words, it is consistent with info in the article. Thus, while statements like "causing a hump in the water on that side" etc is common knowledge, I understand that it is completly wrong! I think this should be mentioned here and in the article on Tides. --GilesW 22:05, 29 August 2007 (UTC)

King Hildebrand is absolutely 100% correct. As it is currently written, saying “centripetal forces cause tides” is pretty much like saying “gravity causes tides.” That much is obvious. However, giving this sort of explanation is worse than saying nothing. The concept of “tides” are now so well entrenched in physics, that any force that varies significantly in magnitude across a distance is known as a “tidal force.” For instance, the effect of being stretched as ones body falls into a black hole (whereby ones feet are pulled more strongly that ones head) is a tidal force or tidal effect.

I can understand also what GilesW is saying but I think the text he's defending doesn't explain his point well at all. Fine, the actual “hump” caused directly by the tidal force is relatively small and is magnified by Earth's rotation, basins, harmonics, etc. We know this because some places, like the Bay of Fundy, see exaggerated effects while others see attenuated effects. Nevertheless, if the Moon were very far away but extremely massive so 1) the barycenter was completely outside the Earth, and 2) the tidal force was near-nonexistent, there would be near-zero “hump” for these other effects to magnify and we would experience no ocean tides.

I don't like making waves (no pun intended) because I don't like to make significant changes to articles the first time I visit them. I've got enough battles on my hands doing slash & burn on other articles. But someone who gives a damn about this article should fix this. An article on the Moon for God's sake, should at least have the issue of tides properly explained.

I would propose something along the lines of as follows (I don’t know how to truncate this into a tight, pithy intro version):

“ Ocean tides are initiated by the tidal force of Moon’s gravity and are magnified by a host of effects in Earth’s oceans. The gravitational tidal force arises because the side of Earth facing the Moon (nearest it) is attracted more strongly by the Moon’s gravity than is the center of the Earth and—even less so—the Earth’s far side. The gravitational tide stretches the Earth’s oceans into an ellipse—with the Earth in the center. The effect takes the form of two bulges—elevated sea level—relative to the Earth: one nearest the Moon and one farthest from it. Since these two bulges rotate around the Earth once a day as it spins on its axis, ocean water is continuously rushing towards the ever-moving bulges. The effects of the two bulges and the massive ocean currents chasing them are magnified by an interplay of other effects; namely frictional coupling of water to Earth’s rotation through the ocean floors, inertia of water’s movement, ocean basins that get shallower near land, and oscillations between different ocean basins. The magnifying effect is a bit like water sloshing high up the sloped end of a bathtub after a relatively small disturbance of one’s body in the deep part of the tub. ”

This, at least, is the full explanation as far as I know it. How one gets that into a compact treatment is beyond me.

Greg L (my talk) 04:39, 1 September 2007 (UTC)

I agree with King Hildebrand and Greg L. I am a physicist, and that "centripetal forces ... barycentre" sentence just baffled me. And if it baffles me, I can't imagine it does much for a non-scientist, so I'm glad it's gone. I do realize now that the picture that was in my head-- the ocean bulges oriented with the moon--was really incomplete. The Moon article made me face that, which is an example of why Wikipedia is so great. But unless the "good" explanation can be made in a few sentences, it's better just to show the bulges, followed by a disclaimer that the continents and rotation make it much more complicated -- the way it stands right now isn't bad. Someone wanting the full picture can go to tides. (However, for some really incomprehensible prose, take a look at the second paragraph of Tides#Tidal_forces -- yikes!). Spiel496 15:19, 2 September 2007 (UTC)

Albedo and Retroreflection

It is well known that the moon is much brighter when it is full, i.e. when the earth is almost between it and the sun. The bright areas of the moon's surface exhibit retroreflection due to the opposition effect, like those projection screens that are coated with small glass beads. This causes the changes of albedo with phase of the moon. Retroreflection This effect causes the halo round the shadow of the astronaut's head reflected in his visor in the well known moon-walk photograph of Aldrin (in the Article), and acts as a fill-in light for the shadow side of objects & people on the moon.

Should not this be mentioned? Has moon dust been shown to be retroreflective? --GilesW 07:34, 30 August 2007 (UTC)

Check out Opposition effect. Lunokhod 23:26, 30 August 2007 (UTC)

Thanks. Are the above changes better, or is it technically incorrect to refer to 'opposition effect' as 'retroreflection'? GilesW 02:13, 1 September 2007 (UTC)

I have checked out opposition effect. 'The usual major cause of the effect' is ascribed to 'shadow hiding'. However the article does not mention other causes of the effect on the moon. It seems evident that the brightest areas on the full moon associated with new craters are too bright to be accounted for by shadow hiding, and that this can only be due to the retroreflection of sunlight by the well known glass spherules found on the lunar surface, i.e. the heiligenschein effect. I presume that this is addressed elsewhere, but cannot find anything about it on the web. GilesW 10:15, 14 September 2007 (UTC)

Opposition surge doesn't require glass spherules. It is a characteristic of most granular media. Consider that if I have a random distribution of grains, some fraction of them will be distributed into configurations that retro-reflect (e.g. three faces of a cube). See the work of Bruce Hapke, among others. Hapke's scattering models aren't 100% accurate, but they are a start. Michaelbusch 16:37, 14 September 2007 (UTC)

Opposition surge may not require glass spherules, but NASA tells us that they are there in this web page: glass spherules. (Revised GilesW 20:18, 18 September 2007 (UTC))

• I request that any local contribution that the glass spherules heiligenschein makes to opposition surge should be described, or the absence of any such contribution should be explained. GilesW 19:56, 18 September 2007 (UTC)

• Is the brightness of the rims and bowls of some craters an opposition effect, and if so, has it been determined whether or not this is due to glass spherules? GilesW 19:56, 18 September 2007 (UTC)

Edit Protect

There is a high volume of edits of vandalism on this page. Why hasn't it been protected? Laaabaseball 21:53, 30 August 2007 (UTC)

Moon capitalization

It should be mentioned that in American English, moon is generally considered to be a common noun and thus not capitalized. Webster's definition of moon: "1. the heavenly body that revolves around the earth from west to east once in c. 27 1/3 days with reference to the stars or once in c. 29 1/2 days with reference to the sun, and that accompanies the earth in its yearly revolution about the sun, reflecting the sun's light: the moon's diameter is is c. 2,160 miles, its mean distance from the earth is c. 238,857 miles, its mean density is c. 3/5 of the earth, its mass is c. 1/81, and its volume c. 1/49  2. this body as it appears during a particular lunar month or period of time, or at a particular time of the month: see NEW MOON, HALF-MOON, FULL MOON, OLD MOON, FIST QUARTER, LAST QUARTER  3. a month; esp., a lunar month  4. same as MOONLIGHT  5. anything shaped like the moon (i.e., an orb or crescent)  6. any satellite of a planet." —Preceding unsigned comment added by 71.107.191.119 (talk) 01:48, 9 September 2007 (UTC)

In American English, either is acceptable: http://dictionary.reference.com/search?q=moon We could mention that.--Father Goose 08:20, 9 September 2007 (UTC)

Wikipedians engage in rampant over-capitalization. Science terms, political titles, and animal terms are all capitalized in Wikipedia, despite being common nouns. --Tysto 16:33, 9 October 2007 (UTC)

IAU Website: Spelling of Names of Astronomical Objects --Ckatz^chat_spy 05:32, 10 October 2007 (UTC)

My opinion (which I one day believed to be the general scientific view, but I got lost along the way) is the following: a non-manmade object that revolves around a planet is called a natural satellite. Planet Earth (capitalised, since there is only one) has one natural satellite: (the) Moon. Stricltly speaking, there is no other object in the universe called Moon or moon. However, many people choose to use moon as a synonym for natural satellite. Nick Mks 07:18, 10 October 2007 (UTC)

The orientation of the Moon

The orientation of the moon relative to the vertical depends on the latitude that it is observed from.

Thus observed from UK latitudes (~50-60 deg N) in the evening, the almost full moon somewhat resembles a face or a skull, hence "The man in the Moon". Seen from southern Australia (~30-40 deg S) in the evening, the full moon seems to be "the wrong way up" and does not resemble a face. (The latter is a personal observation, no known citation.)

It does not appear that the effect of latitude on the moon's appearance is mentioned in the Moon or The Man in the moon articles. I suggest that the latitude effect be mentioned, and that diagram(s) illustrating the effect be added. GilesW 20:40, 13 September 2007 (UTC)

I suggest amending the title of the first photo (Image:Full_Moon_Luc_Viatour.jpg) e.g.: "The Moon as seen from northern mid-latitudes", or whatever, assuming this to be the case. GilesW 11:07, 15 September 2007 (UTC).

The author states that the photo was taken in Belgium. GilesW 19:41, 20 September 2007 (UTC)

Another image of the moon titled "The 3 March 2007 lunar eclipse" is either rotated 90 deg or taken from the southern hemisphere. GilesW 17:24, 15 September 2007 (UTC)

I suggest that WP guidelines or template for moon & planet images, and lunar eclipses in particular, should include latitude, longitude, date and time taken, and have the "top" indicated discretely within the image, in addition to the info about the optical instrument & camera used. GilesW 17:20, 15 September 2007 (UTC)

I don't think the effect of latitude on the Moon's appearance warrants mention in the article. Even at a single location, the Moon's orientation is going to change throughout the night as it crosses the sky. And if it happens to pass directly over head, then who's to say which side is the "top"? Spiel496 04:37, 21 September 2007 (UTC)

Co-incidental size of moon and sun as viewed from the Earth

No mention seems ot be made of the extrordinary phenomenon of the earth-moon-sun relationship that places the apparant diameter of moon and sun the same as viewed from earth.

Is this really co-incidence, are there any good theories? Do similar known planets/moons have similar relationships? Rufty 20:48, 17 September 2007 (UTC)

Definitely coincidence, but worth mentioning, and nothing like it in the solar system. Mars has tiny moons, much smaller than the sun's apparent size. Pluto has a huge moon, many times larger apparent size than the distant sun. Well, observing from any of the 4 big moons of Jupiter, they can be of larger or smaller apparent size than the sun depending on their orbital timing, AND so will total solar eclipses will occur at times. Tom Ruen 20:05, 20 September 2007 (UTC)

RaP> Please leave that out of the main page. The precise eclipse effect, the fact that all formation theories have more or less serious problems together with the near ecliptical inclination and the droplet shape (59% facing...) only lead users in the direction of "somebody put it there" or "somebody used it for space travel". This does not contribute to a serious article and wakes more associations to Star Wars and the Death Star than to solid science. —Preceding unsigned comment added by 64.149.106.249 (talk) 05:32, 24 September 2007 (UTC)

Atmospheric density

Currently, this is given in the infobox in terms of particles per cm³. However, these infoboxes are meant to be a useful way to provide numbers for a comparison between different solar system bodies. No other body has atmosphere given in these units — all the others use pascals, and so should the Moon. Furthermore, rather than using the "surface_pressure" parameter in Template:Infobox Planet, the moon is the only body to use instead the "atmosphere_density" parameter.

The quantities currently given as (10⁷ particles cm⁻³ (day) and 10⁵ particles cm⁻³ (night) ) can be easily converted to Pascals using the Ideal gas law, Avogadro's number to get the number of moles per cm³, and using the surface temperatures given in the present moon article. Since these are order-of-magnitude estimates anyway, it doesn't matter whether we use equatorial or polar temperature. Let's say equatorial: 390 K (day) and 100 K (night). This leads to 5×10⁻⁸ Pa (day) and 1.4×10⁻¹⁰ Pa (night). Since it's an order of magnitude estimate anyway, 10^-7 (day) and 10^-10 (night) can be used. Deuar 11:08, 27 September 2007 (UTC)

"Metric moon" section

Is an entire section devoted to this issue necessary? It was a minor mixup, and even though it was significant, we don't devote sections here to things like Apollo 13... Figured I'd put a note on the talk page instead of removing it altogether. Rompe 05:36, 1 October 2007 (UTC)

Well I originally put the information under the Legal Status section and it just didn't look right. I couldn't find anywhere else to put it - and since it is actually quite a major step forward in international relations I ended up creating it's own section. However, reading it back I do take your point. Maybe it should go back under Legal Status - maybe a subheading? Jim77742 00:08, 2 October 2007 (UTC)

I think it should go back under Legal status, but without the box: only the first two sentences, use a ref for the rest. Nick Mks 07:56, 2 October 2007 (UTC)

I've put Metric Moon back under Legal Status, but retained a sub heading and the quote box. I'm personally happy with this. Other opinions? Jim77742 04:50, 3 October 2007 (UTC)

I don't understand why this is here at all. Shouldn't this piece of trivia be under Nasa? Should it be mentioned that all american scientists use the metric system? and that only the engineers don't? This is really not important... Lunokhod 01:21, 7 October 2007 (UTC)

It should be moved to Exploration of the Moon or somewhere like that. It is not of comparable importance to most of the rest of the things in the article. Deuar 10:01, 7 October 2007 (UTC)

Imperial Units

I notice that imperial units have found their way into this scientific article. All other solar system bodies are metric only and I'm proposing that the moon be no different. I also think endless conversion clutter in an article makes it much less readable.

Putting in conversions like this: 159,265 km (98,963 mi) really are a waste of time because we either need to convey some essence of the number (it's big) OR you may need to use the number in a scientific calculation - and in that case you will always use the metric unit.

I'm proposing the removal of all imperial units from this article. Even NASA and the US have agreed that the moon is metric (http://science.nasa.gov/headlines/y2007/08jan_metricmoon.htm) so why not do it here as well? Jim77742 05:15, 3 October 2007 (UTC)

I concur. Nick Mks 07:06, 3 October 2007 (UTC)

Metric should definitely be first, no question about that. I would like to see Imperial in parentheses but I'm not strongly attached to it. thx1138 07:39, 3 October 2007 (UTC)

I agree, it's not rocket science to divide by 1.6 and get miles, etc. By the way, what about Earth? Deuar 12:49, 3 October 2007 (UTC)

No is not rocket science, but it is a pain to do it every time. The moon and the Earth are general enough articles to include imperial units in the main text. If you hate imperial units, like Jim77742 does, than just skip over them when reading the article. Skipping over something in parenthesis does not require one to be a rocket scientist either. —MJCdetroit 16:39, 3 October 2007 (UTC)

For once I do agree with MJCdetroit. It would be a complete pain to divide by 1.6 each time. But what you should do is NOT convert. If you see 159,265 km you think "a long way". Even I (who went from imperial to metric 33 years ago) cannot picture in my head exactly how big that is (except maybe 320,000 par 5 golf holes!). And anyone reading 98,963 miles is also not going to be able to do that. The km figure is there for a sense of size and an exact figure if anyone needs to do some calculations. The mile figure doesn't add anything useful except clutter.

My argument breaks down say where we may be talking about, say, maximum temperatures of US cities. Of course the Fahrenheit figure provides a useful comparison for US residents when reading it. But scientific articles are different. For example what is the point in listing the sun's density in pounds per US gallon?

So yes skipping over something in parenthesis is easy, but when you have scientific articles with LOTS of figures in the text and every one of those has imperial units in parenthesis it becomes very ugly to read. This is also not new. I've been reading astrophysics papers from mid last century and everything is in metric. No conversions to miles (or other imperial units) anywhere. It would be unthinkable to do that.

In summary my arguments are based on readability. I say that conversions after every number clutter text badly - especially in scientific articles with lots of figures. And I also say that those imperial figures do not actually help anyone. Jim77742 00:23, 4 October 2007 (UTC)

Then why not just say the moon is "a long way" away instead of giving a figure? It maybe unthinkable for a astrophysics paper, but not for an encyclopedia; none of the other major online encyclopedias are metric-only (encarta & britannica).—MJCdetroit 03:39, 4 October 2007 (UTC)

Your web links are to the US sites. My paper copy of Britannica does not mention imperial units in most articles. I would guess other countries (apart from US, Burma and Liberia) Britannicas are the same. Is it a requirement that WP do what the US Britannica does? No.

Do you agree, MJCdetroit, that imperial conversions in parenthesis after every figure (especially in a scientific article which will have lots of numbers) reads poorly?

Should, for example, the density of the Sun be specified in pounds/US Gallon after the metric measure?

Does the content of the parenthesis: "a temperature of 100,000 K (90,700 C, 180,000 F) is reached..." actually have any use? (And yes the Celsius measure shouldn't be there either)

What I'm talking about here is endless useless conversions in parenthesis. It is hard to read. In astronomy articles, the only useful ones are, for example: "The mass of Jupiter is 1.8986×10²⁷ kg (317.8 Earths)". The content of the parenthesis provide extra information that helps the reader get the idea of how big 10²⁷ kg is. Having 4.1857×10²⁷ lb is ridiculous. The parenthesis should provide extra information that the reader may find useful, not information that should only be read by certain people in certain countries.

And if the reader genuinely has no idea sense how long a kilometre is, they can click the link and find out it is 0.62 miles.

The trick here is to learn to think in the units used in the field. Don't convert. For example studying some radio astronomy papers I came across the unit Jansky. Not a strict SI unit and one I'd not heard of. Do I do the conversion to an SI based, watts per square metre per hertz by multiplying by 10^-26 every time I read a figure of, say, 30 Jy? No. You start thinking in Janskys because that's what radio astronomers do.

In science, the units are metric and have been for a long time. The world over. Jim77742 04:28, 4 October 2007 (UTC)

With one objection and the rest support I will remove imperial units to match other solar system bodies. Jim77742 10:26, 5 October 2007 (UTC)

As this article is written in english, it is appropriate to give imperial units in parentheses. Most english speaking people are not scientists, and therefore we should give the units that most people are familiar with. I remind you that this is not a scientific article. Lunokhod 01:26, 7 October 2007 (UTC)

First, this article and all other articles on bodies of the solar system are most definitely scientific articles. Second, only three countries, 4% of the world's population and 16% of the english speaking population come from countries that use imperial units. So if your argument is that we use what "most" people use - then we are doing that with metric units. As I've said it all comes down to readability. If every single figure is going to have an imperial conversion in brackets after it will read like a dog's breakfast. Generally scientific articles have lots of numbers in their text. And every number with a conversion looks just awful. And where do you draw the line? Density of the sun in lb/US Gallon??? Jim77742 11:43, 7 October 2007 (UTC)

At least 84% of native english speakers use imperial units (see english language). Therefore this audience should be served in this encyclopedia article, irregardless of your opinion of these units (which I am in agreement with). As a guide, you should ask yourself: Would a native english speaker use imperial or SI units for this number? Many would use imperial units for things like the Earth-Moon separation and radius of the Moon. In contrast, for the density of the Sun the majority of people who would want to know this number would probably be scientists (Personally, I would just use something like specific gravity).

As to whether this is a "scientific article" or not, you might want to compare with something like Spherical harmonics. That article definitely has a restricted audience, whereas this article would interest grade school students, artists, and scientists alike. Indeed, in order to pass to feature article status, we had to make this article readable to the lay person. Lunokhod 14:25, 8 October 2007 (UTC)

The Moon has an owner

Im actually amazed there is no mention of this in the page, but legaly, the moon has an owner (or at least had one), though a poetic one more than anything. It is the case of Chilean lawyer Jenaro Gajardo Vera, who went to inscribe the whole moon as his property in 1953. Legally, there was no reasson (as there were no treaties yet) that would prevent him from doing so, and although many hoaxers have tried to claim that they owned the moon, Jenaro Gajardo was the first to do so leagally. The reasson?, he was not allowed to enter an exclusive club in Chillan for not owning lands. Gajardo never really tried to profit with his new acquired land, for the Charles Whitman enthusiast he was, this had more of a poetic connotation. His story would had been forgotten and dismissed as the one of a hoaxer, with one little difference: President Nixon actually sent him a telepraph asking for his permission before the Apollo 11 could land on the moon. True story [12], Nixon actually wrote in his telegram "The Moon Belongs to you", Gajardo felt honored for this and very willingly to give his permission, even holding for a short while a series of letters with Nixon. From then on, Gajardo gained a short-lived celebrity status within latin america, he gaved interviews, he appeared on television, etc. Yet his story does not have the same connotation as the ones from hoaxers like Dennis Hope, Gajardo never tried to profit from it, though he became widely famous for it, at least for a while.Kessingler 14:53, 6 October 2007 (UTC)

Do we need both to scale pictures?

Do we need both to scale pictures in section "Orbit and relationship to Earth", I think one is enough. Beast of traal T C _ 19:54, 7 October 2007 (UTC)Beast of traal

Both are highly interesting in their own manner, portraying the light travel time, and the scale. I think they should stay. While the light-travel diagram also shows the scale, I think it is best to keep a separate representation of both for clarity. Deuar 09:18, 8 October 2007 (UTC)

The Kona, Hawaii Conference of 1984, and the process of science

The Big Splat, or How Our Moon Came to Be, Dana Mackenzie, John Wiley & Sons, Inc., Hoboken, New Jersey, 2003, pages 166-167:

"Early in 1983, Bill Hartmann, Roger Phillips (director of the Lunar and Planetary Institute in Houston), and Jeff Taylor (a geologist at the University of Hawaii) decided to organize a conference devoted to the origin of the Moon. It would be held in the resort town of Kona. More than a decade had passed since the last Moon landing, and it was high time to face the biggest mystery left from the Apollo years. They sent out a challenge to their fellow researchers: You have eighteen months. Go back to your Apollo data, go back to your computer, do whatever you have to, but make up your mind. Don’t come to our conference unless you have something to say about the Moon’s birth.

"Hartmann says he never thought that the giant impact model would come out on top in the debate, only that it would get some attention. But in the summer of 1984, he and Taylor got together to read the abstracts that other scientists were sending in, one- to two-page digests of the talks they were planning to give. It was like getting the first exit polls from an election. Hartmann and Taylor could tell then that a big upset was brewing, but no one else knew it until October."

— Preceding unsigned comment added by FriendlyRiverOtter (talk • contribs)

Is this just for our information, or are you trying to start a discussion about something? Cause I wouldn't know about what... Nick Mks 19:38, 24 October 2007 (UTC)

Yes, I would be interested in starting a discussion. And in time, I would also like to help add more about the lines of evidence for giant impact and more about how the theory was developed and accepted. FriendlyRiverOtter 20:05, 28 October 2007 (UTC)

Metric?

Ok so i have nothing against the metric system except i dont use it. How about if we add the US measurements equivalents, hun?Mace Windu 21:05, 1 November 2007 (UTC)

This was just discussed (see an above section) Saros136 22:01, 1 November 2007 (UTC)

Yes, I totally agree. Someone removed the imperial units without adequate discussion here. I think that we should put the alternative unit in parenthesis (I don't care which is the primary). Even though I do not like imperial units, I remind everyone that 84% of native english speakers use Imperial units, and that this article is not a scientific article (even though it is about a scientific subject in some parts). Lunokhod 15:33, 5 November 2007 (UTC)

Nope, it's 71% by my calculator, just in the ancestral anglophone countries and not counting native speakers in places such as India. In the US, young people are introduced in the school system to the measurements used by the rest of the world, so that they can communicate universally. Increasingly, imported television documentaries use metrics alone. US scientific publications tend to use metrics alone. WP does a favour to the 11-year-old school girl who consults this article by providing a link to the first use of each metric unit; US school children, not to mention adults, are advantaged by not being spoon-fed imperial units—think of it as exercising a skill that is taught at school. The conversions are really quite easy to conceptualise and remember, anyway. Halve kilometre and add a little, for example. Removing the constant conversion mantra also does a favour to all other readers by reducing the clutter and thus improving the readability of the text. I didn't remove the conversion clutter, but I do not favour its re-introduction into a scientific article. Although the rules say that if there's no consensus, the old imperial-unit conversions have to clutter again, I ask you all to think twice before pushing for this step. Tony (talk) 03:07, 6 November 2007 (UTC)

How do we get 71%? Even that seems way too high. Anyway, I'm opposed to restoring the Imperial units, per the above and per the discussion about this at Talk:Saturn#Imperial values of measurements. The consensus was to standardize the astronomy articles and bring them in line with the style guidelines for scientific articles. --Ckatz^chat_spy 05:02, 6 November 2007 (UTC)

How about using the Imperial units once, for each rough range? Although I think the physical comparisons are also a good step, making Imperial units less necessary. Saros136 06:57, 6 November 2007 (UTC)

Question: Is the primary purpose of this page to serve practicing scientists? I would suspect that the widest audience is non-scientists interested in the Moon, especially with all the lunar missions that are going on. The majority of non-scientist native english speakers clearly use imperial units. Please look at english language. The chart shows that 84.1% of native english speakers are from the US and UK combined. Of course we can quibble about the details, but the point is that at least half of native speakers use imperial units (and probably more), so this demographic should be served. Lunokhod 19:14, 6 November 2007 (UTC)

The death of the moon

Eventually the earth will loose the moon. I would like to know more about that if possible. Is it going to crash into Earth or be shot off into space? When is this predicted to occur? What will the side effects be to life on Earth?... Its all speculative science... but its good reading. —Preceding unsigned comment added by 124.168.86.197 (talk) 10:00, 3 November 2007 (UTC)

No, the Earth will not lose the Moon. This gets mentioned in some of the above discussions, and in the article. Saros136 10:25, 3 November 2007 (UTC)

Experts at NASA answer the question of "will the Moon leave Earth?" and many other questions related to the Moon and Earth. Jecowa (talk) 23:16, 24 November 2007 (UTC)

Poor prose and non-compliance with MOS

A brief review of this article reveals that it does not meet the requirements of FA Criteria 1a and 2. Here is an example:

Moreover, the 18.6 year nodes cycle has also influence on it, as when the ascending node of the lunar orbit is in the vernal equinox, the lunar declination can go as far as 28° each month (which happened most recently in 2006). This results that the Moon can go overhead on latitudes till 28 degrees

I wonder whether the nominator for FAC and other contributors are in a position to organise for the article to be properly copy-edited. This could be done as part of the FAR/C process, or less formally to forestall such action.

Thanks. Tony (talk) 12:21, 28 November 2007 (UTC)

I went through the article and did a few copy-edits. It does not appear to be that bad. Most vandalism (even the sneaky ones) seems to have been reverted correctly, and the rare bad sentence, in new sections, is probably accidental. I don't see many others of these, apart from the section you quoted. And thus I requested semi-protection again after all. Nick Mks (talk) 19:18, 29 November 2007 (UTC)