Talk:Moon/Archive 12

Latest comment: 14 years ago by Brews ohare in topic Precession of Moon's orbit
Archive 5 Archive 10 Archive 11 Archive 12 Archive 13 Archive 14 Archive 15

Minor line-spacing problem above Eccentricity line.

[From Solspot] The line "Semi-major axis 384,399 km" appears as 384.399 (the comma appears as a decimal point; it may mislead a reader). Perhaps it's overlaid by the line below: "Eccentricity 0.054". It seems ok in the source, but I can't identify the line-spacing command. Solspot (talk) 18:43, 16 September 2009 (UTC)

NASA water discovery

Can someone put in a mention about this as it just featured on the news and is very important - a large quantity (by lunar stantards anyway) was found in the soil. According to the scientist on the news if you squeezed a washing machine full of the soil you would get about a litre of water from it. He did not mention the type of water however. 78.145.175.176 (talk) 17:27, 24 September 2009 (UTC)

There has recently, been the detection of air molecules also. The implications of this are immense. With no atmosphere on the moon, the detection of air molecules would signal the presence of intelligent life being contained with an advanced life support type system. —Preceding unsigned comment added by 70.81.5.20 (talk) 07:19, 8 October 2009 (UTC)

Water on the moon is confirmed. Any of these new imagesImage1 Image2can be introduced into the section.Bcs09 (talk) 02:11, 25 September 2009 (UTC)

Volcanic Pearls

These are mentioned in the article but no explanation or hyperlink is given.

Hiya 82.39.112.228, and welcome to Wikipedia! The link you are looking for is the "Main article" link at the beginning of that section called Lunar ice. The volcanic pearls are explained there. Also I added another reference citation from the Lunar ice article that does not have to be translated. Hope this helps! (As soon as somebody creates an article all about those volcanic pearls, then it can be linked to. <g>)
 —  .`^) Paine Ellsworthdiss`cuss (^`.  06:33, 4 October 2009 (UTC)

Infobox ambiguity

On the line for 'Volume,' the units are in cubic kilometers, but the link is shown as k[m^3], which may (?) lead people to believe that we are talking about thousands of cubic meters, rather than billions of cubic meters.

KJBurns (talk) 16:14, 4 October 2009 (UTC)

The link for km³ now goes to 1 E+9 m³. Isn't that better?
 —  .`^) Paine Ellsworthdiss`cuss (^`.  16:36, 4 October 2009 (UTC)

The Moon

The moon is earth's only natural satellite and the fifth largest in the Solar System. The average centre-to-centre distance from the Earth to the Moon is about 384,403 kilometres (238,857 mi), about thirty times the diameter of the Earth. The common centre of mass of the system (the barycentre) is locatedd at aboout 1,700 kilometres (1,100)--- aquater the Earth' radius----- beneath the surface of the Earth. —Preceding unsigned comment added by 169.203.211.111 (talk) 22:52, 27 October 2009 (UTC)

Object close to the Moon

The picture that show the "halo" around the Moon, have something strange. It isn't true? --Little bishop (talk) 17:57, 31 October 2009 (UTC)

Eclipses

This statement "Likewise, about 600 million years from now (assuming that the angular diameter of the Sun will not change), the Moon will no longer cover the Sun completely and only annular eclipses will occur.[69]" is not supported by the cited source "69" which is "^ a b Thieman, J.; Keating, S. (2006-05-02). "Eclipse 99, Frequently Asked Questions". NASA. http://eclipse99.nasa.gov/pages/faq.html. Retrieved 2007-04-12.". According to that source, the number is 1 billion years. However, the following source does say 600 million and it's also a NASA source: http://sunearthday.nasa.gov/2006/faq.php. The source or the number of years should be changed, however, that does beg the question about which source, if either, is accurate. If someone or some persons are keeping a close eye on this page, please advise.Rodney420 (talk) —Preceding undated comment added 22:05, 13 November 2009 (UTC).

Increasing Earth-Moon distance by 3.8 cm

Is this line appropriate to add to article?

By coincidence, diameter of corner cubes in retroreflectors on Moon is also 3.8 cm with references http://eclipse.gsfc.nasa.gov/SEhelp/ApolloLaser.html http://www.physics.ucsd.edu/~tmurphy/apollo/lrrr.html

Thanks! Rāmāh (talk) 21:52, 24 November 2009 (UTC)

I don't thinks so. This is almost WP:SYNTHESIS, although if you had been WP:BOLD and put it in, people might have left it in. Martin451 (talk) 22:18, 24 November 2009 (UTC)


The section 'Orbit and relationship to Earth' says 'As a result of the conservation of angular momentum, the slowing of Earth's rotation is accompanied by an increase of the mean Earth-Moon distance of about 3.8 m per century, or 3.8 cm per year.[68]' However the source cited makes no such assertion. It states that there is an indication that there is a relationship between tides and the increasing distance between the Moon and the Earth. I don't think Earth's tides can be claimed as a proven cause or the one and only cause of this increase in separation. Blueshift999 (talk) 10:12, 11 March 2010 (UTC)

Committed to Moon?

Intro, para 3 says:

The U.S. has committed to return to the Moon by 2018.[5][6][7]

All citations is from 2005. It needs update with at least some Oct/Nov 2009 fact link, because of the economical crisis and Obamas decisions on the space programs. ... said: Rursus (mbork³) 16:33, 27 November 2009 (UTC)

At the moment the statement is still factual. They are planning to return to the moon in 2018, and until they specifically state otherwise, it's not appropriate for us to say so. SeanBrockest (talk) 19:27, 15 January 2010 (UTC)
Update, if the current bill passes, we'l have to make the suggested change. SeanBrockest (talk) 04:02, 3 February 2010 (UTC)
ahh hell, i went ahead and made the edit anyway SeanBrockest (talk) 04:02, 3 February 2010 (UTC)

Hole in the Moon Could Shelter Colonists

This site: [Fox] writes that hole in the Moon could shelter colonists.Agre22 (talk) 20:43, 3 January 2010 (UTC)agre22

Article needs grammatical corrections

In the section "Ocean Tides" I have changed three things:

1) I added, parenthetically, that the sun also contributes to the ocean tides, with about half the gravitational effect of the moon.

2) I corrected two or three occurrences of "nearest" and/or "farthest" where, in comparing two objects, it should be "nearer" and "farther".

") In one paragraph only, I corrected a repeated capitalization error. In the phrase "I live on Earth", the upper-case "E" is correct. In the phrase "I live on the earth", the "e" should not be capitalized. Likewise, "the moon" requires a lower-case "m". This capitalization discrepancy should be corrected throughout the entire article, but I didn't take the time to do it, because someone may simply reverses my efforts. In any case, the way it stands now, the capitalization is incorrect. Worldrimroamer (talk) 16:10, 14 January 2010 (UTC)

I was mistaken about something: The use of "nearest" and "farthest" was, in this context, NOT incorrect. I went in to change it back to the way it had been, but someone had already done it for me. Good. However, someone also changed the occurrences of "the earth" back to "the Earth". This is simply incorrect. Someone please comment on this. Worldrimroamer (talk) 16:26, 14 January 2010 (UTC)
I was that someone. Sorry not to reply here earlier - I think you wrote this between my seeing your changes and partly reverting them. My change to the capitalisation was based, as I said in my edit summary, on Wikipedia:MOSCAP#Celestial_bodies which says "These terms are only proper nouns when referring to a specific spectral body", and gives "The Moon orbits the Earth" as an example of correct useage. Olaf Davis (talk) 17:12, 14 January 2010 (UTC)
Incidentally, I have no idea what a 'spectral body' is except perhaps a ghost - I've changed it to 'celestial' in the guideline. Olaf Davis (talk) 17:19, 14 January 2010 (UTC)

the moon

The Moon was called Luna by the Roman's,Selene and Artemis bt the Greek's.The Moon's orbit is 384,400km from Earth.It's diameter is 3476km and it's mass is 7.35e22kg.It is the second brightest object in the sky after the Sun.As the Moon orbit's around the Earth once per month,the angle between the Moon and the sun change's. —Preceding unsigned comment added by 86.158.161.214 (talk) 15:23, 24 January 2010 (UTC)

Orbit of Moon with respect to Sun

The path of the Moon with respect to the Sun in the diagram "Phases of the Moon" in the section "Orbit and relationship to Earth" is incorrect in showing the Moon curve away from the Sun. In the entry Orbit of the Moon, section "Path of Earth and Moon around Sun", the correct relationship is stated "The Moon's orbital path around the Sun . . . is always convex outwards", which means that the Moon's path/orbit is always "concave to the Sun". In other words, the path of the Moon about the Sun resembles an approximately 13-sided polygon with rounded sides and corners. It's motion is never away from the Sun. This diagram "Phases of the Moon" should be corrected by removing the reversal in curvature shown at left and right ends. I am not qualified to make such a correction and rely on the expertise of other editors. Phaedrus7 (talk) 22:20, 30 January 2010 (UTC)

I believe that if you search back through the talk page archives here, you will find this has been discussed before. More than once. ;) As I recall, the motion shown in the diagram is correct within its own context, a "flattened out" piece of the moon's orbital path. It would be necessary to show the whole Earth-Moon-Sun system to show the continuously-concave orbital path, and that is not what this diagram is intended to show. The Moon is indeed anomalous among solar-system satellites in it's convex orbital motion, and I don't see that fact elucidated in the section. If you read the archives, you might figure out why that is. ;) I'd agree the fact should be discussed, but the diagram needs to stay as is to preserve it's own consistency. Franamax (talk) 23:39, 30 January 2010 (UTC)

Franamax is factually incorrect stating "It would be necessary to show the whole Earth-Moon-Sun system to show the continuously-concave orbital path" of the Moon, as would be apparent by examining the figure on p. 178 of Christopher P. Jargocki's 1976 book Science Brain-Twisters, Paradoxes, and Fallacies. This figure correctly portrays the intertwined paths of Earth and Moon over the same time span as the "Phases of the Moon" diagram. Thus, while this concave behavior is not discussed in the section, it is not necessary for this diagram to portray an incorrect geometric relationship between the orbits of Earth and Moon. Phaedrus7 (talk) 22:01, 31 January 2010 (UTC)

In view of the fact that illustrations often distort reality (as is the case here), perhaps the distortion of the Moon's true path about the Sun might be pointed out in a note in the "Phases of the Moon" diagram. Phaedrus7 (talk) 23:50, 31 January 2010 (UTC)

Only Natural Satellite?

The opening line to this article states that the moon is the "only natural satellite" to the earth. This is only half true. While scientists are very clear that the 4 other items orbiting the earth are not moons, I think they do fit the definition for natural satellite. Opinions? SeanBrockest (talk) 21:14, 11 February 2010 (UTC)

See: quasi-satellite, 3753 Cruithne, talk archive 3, talk archive 6, talk archive 6 II. -- Kheider (talk) 21:36, 11 February 2010 (UTC)
I agree that the "only natural satellite" text needs to be adjusted. 2006 RH120 though small, does regularly enter Earth orbit and while rising to the level of a moon, it is a natural satellite for a year every 21 years.--RadioFan (talk) 10:00, 25 February 2010 (UTC)
Being that 2006 RH120 is not bound to the Earth and is often 2AU from the Earth, I see it as a mere quasi-satellite. -- Kheider (talk) 10:31, 25 February 2010 (UTC)
Details of it's orbit can be included, but the issue here is the claim that the moon is the "only natural satellite" is overly broad with 3753 Cruithne and 2006 RH120 in mind.--RadioFan (talk) 10:39, 25 February 2010 (UTC)
I do not think "temporary satellite capture" (TSC)s should be included since the moon is the only natural satellite BOUND to the Earth's Hill sphere. But I am certainly open to the opinion of others. -- Kheider (talk) 11:21, 25 February 2010 (UTC)
This has been debated repeatedly and at length on Wikipedia, but the outcome has been consistent based on the established scientific consensus. Should the IAU and other bodies decide that the others qualify as natural satellites, we can certainly change the text, but it is not up to us to make the call on their behalf. --Ckatzchatspy 21:20, 25 February 2010 (UTC)

Lunar albedo from peer review

I see that you have adjusted the lunar albedo down further, peer review work from the most respected optical journal on the planet puts the lunar albedo at 7 degrees phase at 13.62% as measured by the most accurate radiometer ever flown in space, see:

2008 G. Matthews, “Celestial body irradiance determination from an under-filled satellite radiometer: Application to albedo and thermal emission measurements of the Moon using CERES” Applied Optics. Vol 47, No 27, pp 4981-4993

The wikipedia value is now over 30% incorrect, please do not hesitate to contact me with any questions.

Dr Grant Matthews

Snerby (talk) 02:30, 26 February 2010 (UTC)

Corrected. Self-promotion is discouraged, but the previous ref was from 1972 and might be simply a patch to support the previous value. Materialscientist (talk) 02:59, 26 February 2010 (UTC)

Name and etymology

... related to the Latin mensis and Ancient Greek μήνας (mēnas) both meaning month, and Μήνη (Mēnē), (alternate name for Selēnē in Ancient Greek) {{editsemiprotected}} —Preceding unsigned comment added by Arty2 (talkcontribs) 12:29, 3 March 2010

Please provide appropriate reference(s) to reliable sources, and reinstate the request.
Also, please sign your name with ~~~~ when you leave messages. Thanks,  Chzz  ►  19:47, 4 March 2010 (UTC)

  Not done

My apologies, you're correct in that I should provide proper reference. Unfortunately guides for suggesting edits to protected pages are not that userfriendly... {{editsemiprotected}}
Information on Selene-Mene found in [Dictionary of Greek and Roman Biography and Mythology: Oarses-Zygia By William George Smith]
Etymological relation of menas (moon) and mania in [Thesaurus graecae linguae, Volume 5 By Henri Estienne] --Arty2 (talk) 22:03, 6 March 2010 (UTC)
Sorry that the instructions aren't great; for help, I recommend talking to a real person with this link.
Done; I assume it should go after the part on 'Menses'? Hope it's OK; let me know if not. Thanks for the further details.  Chzz  ►  22:42, 6 March 2010 (UTC)

  Done

Two sides of the Moon image formatting

Could someone please fix the table formatting for the set of images here? I can't quite get it to line up properly. Iridia (talk) 01:12, 16 March 2010 (UTC) Fixed it. Iridia (talk) 06:24, 17 March 2010 (UTC)

"dark side" is actually less dark

Tiny nitpick alert! The far side of the moon does not get "exactly" the same amount of illumination as the near side. The near side is sometimes in the Earth's shadow (lunar eclipse) but the far side never is. So the far side gets (on average) slightly more illumination.

Even tinier nitpick alert!!

And the moon is closer to the Sun when the far side is illuminated, so again it gets (very slightly) more illumination. Oh, heck, I forgot to factor in the effect of reflected Earthlight, which of course only illuminates the near side. Anyway, I propose that "exactly" be changed to "almost exactly". —Preceding unsigned comment added by 74.78.209.93 (talk) 02:38, 17 March 2010 (UTC)

Internal Structure

I was going to fix up the cross-section image of the Moon Image:Moon Schematic Cross Section.svg, but more I look at it the more problems I have with it.

  • It has no citations
  • The measurements are ambiguous, as it is not clear what distance is being measured.
  • There are no measurements for three layers: the crust, the inner mantle, and the outer mantle.

Michael JasonSmith (talk) 11:24, 23 March 2010 (UTC)

I am removing the image and putting it here (hidden) until it is fixed. Iridia (talk) 23:25, 23 March 2010 (UTC)

Request for comment: lead

I have written a draft version of a new lead at Talk:Moon/Lead to more comprehensively reflect the contents of the article, per WP:LEAD, as part of the FAR improvements. Please could you comment and suggest improvements. Iridia (talk) 05:51, 26 March 2010 (UTC)

Mass Clarification

The mass of the moon is described on the side bar as "(0.012 3 Earths[1])". Why is there a space between the "2" and "3" digits?

--90.199.197.182 (talk) 10:23, 30 March 2010 (UTC)ManInStone

It's common to leave spaces between groups of three digits after a decimal point, similar to the comma (or point, in some countries) before the decimal: 1,234.567 890. However, leaving a single figure in a group on its own looks a bit funny and is usually avoided so I've changed it. See the last bullet point here for the relevant guideline. Olaf Davis (talk) 10:38, 30 March 2010 (UTC)
Actually MaterialScientist beat me to it. Olaf Davis (talk) 10:43, 30 March 2010 (UTC)
I have removed all those spaces - they are not really conventional in science. As to the WP guidelines, they say such numbers may be delimited using thin spaces, i.e. no real guideline. Per common sense, I understand separating groups in large numbers (pi, etc), but not when there are only 4-6 digits. Materialscientist (talk) 10:53, 30 March 2010 (UTC)

Ancient values for the Moon's size and distance

For some bizarre reason, Ptolemy's values for the Moon's size and distance were not given in the Moon#Early studies section. I've added these and removed the following text:

These values were calculated more accurately between 825 and 835 AD by the Persian astronomer, Habash al-Hasib al-Marwazi, at the Al-Shammisiyyah observatory in Baghdad, who estimated the Moon's radius as 1,520 km and its distance from the Earth as 346,000 km.

The source was given as

Langermann, Y. Tzvi (1985). "The Book of Bodies and Distances of Habash al-Hasib". Centaurus. 28: 108–128 [112]. doi:10.1111/j.1600-0498.1985.tb00831.x.

These values do not seem to be any more accurate than those given by Ptolemy. Also the usual way to discuss these measurements is in terms of multiples of the Earth's size, rather than in any other units, as that separates the accuracy of these measurements from that of the Earth's size.

All the best. —Syncategoremata (talk) 15:29, 8 April 2010 (UTC)

I've restored al-Hasib's estimates, because I think they are also noteworthy for giving the estimates in terms of miles. Regards, Jagged 85 (talk) 18:23, 8 April 2010 (UTC)
I've removed this once more because the figures used by al-Hasib are taken directly from Ptolemy: to quote the article, "These computations are based upon the relationships between the diameters, etc., of these bodies as found as in Almagest, especially book V" (p. 110). Therefore the only interest in these figures depends on the figure he uses for the radius of the Earth, which according to:
Mercier, Raymond P. (1992). "Geodesy". The History of Cartography: Vol. 2.1, Cartography in the traditional Islamic and South Asian societies. Chicago & London: University of Chicago Press. pp. 175–188 [178–181]. ISBN 978-0-226-31635-2. {{cite book}}: Unknown parameter |editors= ignored (|editor= suggested) (help); no-break space character in |title= at position 28 (help)
is simply the Roman value (of 75 Roman miles per degree of latitude) converted into Arabic units.
All the best. —Syncategoremata (talk) 19:39, 9 April 2010 (UTC)

Compass on the moon?

I know that this may not be the place to ask, but I had a question. I know that the moon does have a gravitational field, but what would a compass do on the moon? Will it follow Earth's field, or would it have it's own direction? P.S. - If this is not the right place to ask, please point me there.  A p3rson  17:29, 10 April 2010 (UTC)

These kinds of questions belong on the WP:reference desk, but that's okay.
You mean to say you know the moon doesn't have a magnetic field, right? - sorry, misread your question.
Actually, it does, but it's The moon's magnetic field is very very weak. You'd need a very sensitive compass to detect it. Worse, it's not a dipole (north vs south) field, but a bunch of small local fields. So your compass will point in different direction depending on where you are (which local field you're in), and would be rather useless for navigation. I suppose that if you were just wandering around a moon base, and happened to be in a local field, it might be good enough to get you home if you're lost even though it wouldn't point north (I say "might" because there might be interference from orbiting through the Earth's magnetic field, which might cause your sensitive compass to go all wonky, but I don't really know), but the giant stationary Earth in the sky would probably be a better guide. kwami (talk) 18:10, 10 April 2010 (UTC)

Significant figures

"4.527 ± 0.010 billion years ago". Is there any justification for such an incredibly precise value? Mtpaley (talk) 22:22, 10 April 2010 (UTC)

Animation not working

Hi. Is there a reason why the animated graphic showing the yellow light beam is no longer animated? I don't see any beam at all, either on this article or here, yet the display here is OK. I'm using IE 8. 86.152.242.168 (talk) 00:47, 14 April 2010 (UTC).

I know this problem for some time: animated gifs do work, but only when not resized (i.e. removing 600px from the mentioned image in the article will re-animate it, but then we can't see the moon). Anyone knows more about it? Materialscientist (talk) 01:32, 14 April 2010 (UTC)

Precession of Moon's orbit

I don't see this effect mentioned any longer in the article. It is an important omission, IMO. Brews ohare (talk) 13:16, 5 May 2010 (UTC)