Talk:Mars/Archive 8

Latest comment: 13 years ago by Saros136 in topic JPL fact sheet distances
Archive 5 Archive 6 Archive 7 Archive 8 Archive 9 Archive 10

Composition Figures

There seems to be something wrong with the figures given for the composition cell (95.72+2.7+1.6+0.2+0.07+0.03+0.01 ). When adding these, they amount a total of more than 100.33%. Can somebody review them?--Email4mobile (talk) 17:19, 13 April 2010 (UTC)

Yep, good catch. The Atmosphere of Mars article lists 95.32 for the CO2 content. That changes the total to 99.93%.—RJH (talk) 15:44, 15 April 2010 (UTC)

and what`s about the last 0.07%?! --Abbad Dira (talk) 17:20, 16 April 2010 (UTC).

Interesting question, I wondered that myself. Also, according to this, the O2 content is only 0.13%, so the remainder would actually be 0.14%.—RJH (talk) 17:53, 16 April 2010 (UTC)

see this, according to this link the figures is: "95.32-2.7-1.6-0.13-0.07-0.03", and the total is 99.85%. and the last 0.15% is trace amounts of neon, krypton, xenon, ozone and methane --Abbad Dira (talk) 13:39, 18 April 2010 (UTC).

Yes, his data comes close to matching what is on the Mars Fact Sheet, which is probably the original source for the data on this article. (I think the data may have since been modified based on some unknown source, or else subtly vandalized.) For now, I updated them accordingly in lieu of a journal article (which would be preferable). The water, nitrogen oxide and neon add up to 0.0313%. I'm not sure the trace amounts can account for the difference, since they are down in the parts per billion range. Thanks.—RJH (talk) 18:54, 18 April 2010 (UTC)

An Ocean

After studies, it claims there was once an ocean covering a third of Mars, sometime 3.5 billion years ago. Should we add this?

http://www.tgdaily.com/space-features/50189-ancient-martian-ocean-may-have-supported-life

(TheGreenwalker (talk) 18:54, 23 June 2010 (UTC))

My suggestion is that the section on Hydrology would be the best place for a summary.—RJH (talk) 21:50, 23 June 2010 (UTC)

Off topic external link

The external link: Martian Law – a CATO white paper giving a partisan version of what Law on Mars ought to be is not about Mars. It might be about the Colonization of Mars. I removed it from the article on Mars. The link was added by User:68.34.238.159 on the 13th of February in 2005 as revision # 10315169. There have been only two edits by this IP address, both on that date. --Fartherred (talk) 08:53, 28 June 2010 (UTC)

Works for me. Thanks.—RJH (talk) 16:55, 28 June 2010 (UTC)

possible small amounts of liquid water on the surface, enought to widen a channel?

http://www.reuters.com/article/idUSTRE63B5MT20100412 and http://hypertextbook.com/facts/2001/AlbertEydelman.shtml state that temperatures may get slightly above freezing just enough to melt small amounts of liquids, and that channels become slightly longer. is this article-worthy, or should it go to the water on mars article?

97.81.100.122 (talk) 01:35, 13 April 2010 (UTC)

If it does, I think it should be counter-balanced by the chemical analysis of the Mars meteorites showing that the surface has been below freezing for most of the last four billion years.—RJH (talk) 14:40, 13 April 2010 (UTC)

I think that that would make the most sense of any option. 97.81.100.122 (talk) 22:45, 13 April 2010 (UTC)

in the chapter about life, its said than mars has "insufficient atmospheric pressure to retain water in a liquid form (water instead sublimates to a gaseous state)". In some regions (e.g. Hellas Planitia) this is not true, the pressure there is 1,155 Pa (1.155 kPa), according to the chapter about the atmosphere. the Water Data Sheet on WP states that the vapor pressure water at 8 degree centigrade is 1.07280 kPa. the temperature during summer in the southern hemisphere is sometimes also high enough (according to german wikipedia). thus: liquid water should be possible on the surface of mars. 86.135.192.41 (talk) 02:04, 18 April 2010 (UTC)

The statement in the article about "insufficient atmospheric pressure to retain water in a liquid form" is correct for most of Mars' surface, so it should be kept. On the surface of Mars at the lowest elevations and highest atmospheric pressures water would be just barely possible if the entire atmospheric pressure were water vapor. However, ambient water vapor is blown away by the wind and not replaced, accounting for the variable trace of water vapor in Mars' atmosphere. There is about 0.15 Pa of partial pressure of water vapor. If there were ice at the bottom of Hellas Planitia and if it warmed, it would not get warm enough to melt. It would cool by sublimation before it ever got that warm. The wettest spot on the surface of Mars is dryer than any region on Earth. Water vapor on Mars and on Earth moves from one spot to spot. It condenses and reevaporates as temperatures change. The difference is that on Mars the evaporation is occurs at temperatures as low as -70 C. The resultant situation that there is insufficient water vapor pressure to retain liquid water even is the small area where atmospheric pressure, if all water vapor pressure, could sustain liquid water is different from the article only by a quibble.--Fartherred (talk) 16:03, 30 June 2010 (UTC) By the way the partial pressure of water vapor on Mars can be obtained by multiplying the ppm of water in the atmosphere from the Mars Fact Sheet by the 700 Pa surface pressure. --Fartherred (talk) 16:21, 30 June 2010 (UTC)

The possessive case of Mars

Dante51763 recently changed Mars's to Mars' in two instances. Tbhotch reverted one of those instances. That leaves the article with five instances of Mars' and thirteen instances of Mars's in the text and seven instances of Mars' in names of publications cited as references. Tbhotch referred to British English, but I am only familiar with the United States of America's English. I looked on The Planetary Society's web site and found "Mars Climate Sounder: Observing Mars' Atmosphere for Two Mars Years." So I have no evidence that the British spell the possessive of Mars as Mars's. I am inclined to change Mars's to Mars' in all instances, but having one uniform spelling is better than a mixed batch. --Fartherred (talk) 14:36, 15 July 2010 (UTC)

It would nice to ask to the major contributors in which dialect is written the article. TbhotchTalk C. 16:24, 15 July 2010 (UTC)
My surname ends in s and I add the 's if referencing my personal possession. If I were referencing a possesion of my family (plural), I would end with ...s'. I seem to do as this defines as correct. I don't believe there is any difference between American English and British English in this case. I would suggest that either way is acceptable but should be consistant throughout the article. What do the major contributors think? gonads3 19:11, 15 July 2010 (UTC)

I wasn't aware this was a dialect issue; the s' ending only occurs, as far as I know, in a plural possessive. Since Mars is not plural, there is no case to use it. Serendipodous 19:25, 15 July 2010 (UTC)

I'd agree, but then I'm a bit old school. I understand dropping the extra s is a little more modern. Perhaps this is the way this article should go. gonads3 19:39, 15 July 2010 (UTC)
Let us try to get some reliable sources. As the references are numbered in the latest version of the article #s 26, 46, 48, 72, 101, 105 & 189 use the spelling: "Mars'." Ditto for The Planetary Society's web site in the example I gave above. We have time to seek sources, since there is no hurry about any of this. -- Fartherred (talk) 21:39, 15 July 2010 (UTC)
This could go on forever. NASA for example contradicts itself, on this page and on ref 46. Just use Mars'. It's modern and probably the way of the future. Quit living in the past, a famous person once said. :) gonads3 22:03, 15 July 2010 (UTC)
I tried a search engine looking for the exact phrase "Mars's atmosphere" or "Mars' atmosphere." I got 35 hits for "Mars's atmosphere" and 513,000 hits for "Mars' atmosphere." The search engine was not as good at recognizing "Mars' atmosphere" and about half of those hits were false positives with even a few "Mars's atmosphere" containing pages thrown in, but it seems that "Mars' " is in the clear majority on the internet.
I am not quite willing to wait forever for input into this discussion, but I could go three of four days to see if there is anyone who can bring in a reference with some claim to authority. --Fartherred (talk) 00:29, 16 July 2010 (UTC) I can see how waiting three days for other editors to notice a discussion could be a bother to someone if he feared forgetting completely about the matter while attending to other things. I just set a note on my calendar to come back to a discussion at the right time. Then if no one else implements the consensus, I am here to take care of it. Waiting is the ideal thing to do by multitasking. -- Fartherred (talk) 06:36, 16 July 2010 (UTC)
There's a grammar inconsistency, and someone is attempting to reconcile it in good faith. Many have contribututed their opinions, but the issue isn't really clear yet, as no one is direclty citing reliable sources on the grammar issue, either US ior British/Commonwealth sources. That's what we need to do here, and that can at least give the editors something concrete to work with in making a decision. It may have even been dealt with in the MOS somewhere before, if we knew where to look. - BilCat (talk) 08:39, 16 July 2010 (UTC)

OK. Here's the info from Strunk and White:

Form the singular possessive of nouns ending in s with 's: Mr. Jones's dog, Maris's foibles, James's dissertation. The only exceptions are ancient proper nouns: Jesus' disciples.
However, you form the plural possessive of nouns by adding an apostrophe after the "s": the dogs' bones, the balloons' strings, the lollipops' centers.
In the case of the plural possessive of nouns ending in s -- as in, say, the family Jones and their collective beach house -- you add an es and an apostrophe at the end: the Joneses' beach house, the Moraleses' car.

Emphasis mine. The question is, does "Mars" qualify as an "ancient proper noun"? I'd say yes if we were referring to the god Mars, no if we are referring to the planet Mars. But that's just me. Serendipodous 08:40, 16 July 2010 (UTC)

OK, thanks. I'll check my old college grammar book from the 80's, Little, Brown Handbook, and see waht it says. Its in US English. What English variant is Strunk and White in, and when was it published? - BilCat (talk) 08:51, 16 July 2010 (UTC)
USA, 1918. Serendipodous 10:12, 16 July 2010 (UTC)
For another example, Encyclopædia Britannica uses Mars's, but far more often uses Martian.Saros136 (talk) 10:31, 16 July 2010 (UTC)
The Oxford English dictionary (British) suggests it should be Mars's if it's a name, which it is (Proper noun, Captial M, etc...). It also suggets it should be Mars' if it's a place, which I would say it isn't really. Since it's Language and continually evolving, few references will be found to the modern approach of ...s', which is taught today in British Schools. I would argue that this is correct for the age we live in. I may not be in agreement with everyone else, but would accept either through concensus. I would expect, however, that this argument may arise again in a number of years if the referenced method is adopted here. gonads3 18:10, 16 July 2010 (UTC)
I don't get the distinction. Presumably, if it's the name of a place, it's a name. Serendipodous 18:19, 16 July 2010 (UTC)
As suggested peviously, we could just substitute with ... the martian ... or ... the martian's .... Do we need to vote, to show concensus? Either way has to be acceptable. gonads3 18:29, 16 July 2010 (UTC)
We should also consider the answer applicable to Venus and Uranus! Uranus is consistant, Venus is not. gonads3 18:34, 16 July 2010 (UTC)
Here in Canada, where we use mostly British grammar and American vocabulary, I was always taught that if the word ends in an 's', there's no 's' following the apostrophe. No exceptions, at least none that I remember hearing about. And I don't forget much (so modest, I am!). I pride myself on having impeccable grammar. –Schmloof (talk · contribs) 18:57, 16 July 2010 (UTC)
This, I like. Consistency is the key. Perhaps we need a bot to ensure the whole of Wikpedia is consistent. :) gonads3 19:16, 16 July 2010 (UTC)
The proposal of gonads3 should take care of the problem. This is not a vote (no!) just a little encouragement. -- Fartherred (talk) 15:27, 19 July 2010 (UTC)

Proposal

If nobody objects, I will reword the specific sentences in line with this option for inanimate objects. Thus ensuring all three articles, Mars, Venus and Uranus are consistent and avoiding future issue. I will make these modifications some time on the 19th of July, unless someone beats me to it. gonads3 22:40, 17 July 2010 (UTC)

I think we only need to be internally consistent within each article. There's no need to enforce the same grammar and dialect rules on all the planet articles.—RJH (talk) 18:54, 19 July 2010 (UTC)
I'll be delaying this planned activity. Should be okay in a day or two. gonads3 20:06, 19 July 2010 (UTC)
I have made an attempt at eliminating the possessive case of Mars from the article. People can look it over for mistakes and see if they like it. If a mistake I have made is fixed, then the fix and my edit will need to be eliminated together to get back to the former condition. If no edits overlap mine then my edit can still be undone. --Fartherred (talk) 18:06, 20 July 2010 (UTC)
Nice work. Although there are a few other possessives that lack consistency, for example, Phobos' and Phobos's. I'll get these at some point, unless the masterful Fartherred beats me to it. gonads3 18:34, 20 July 2010 (UTC)
I appreciate the efforts of gonads3 but I also agree with RJH that we only need to be internally consistent within each article. The recent edit by gonads3 on the 25th of July at 20:10:29 hours universal time contained a definite error in changing (scientists' theories) to (scientists have theories). Removal of the correct possessive plural, moons', made the text less clear. The use of (cleaned the solar panels of both rovers) is more cumbersome than the previous correct possessive plural. I will change these back to the original. I advise that the elimination of possessive case be considered as only an option to bring internal consistency to an article where there is some established problem, not a style mandatory for all of Wikipedia. --Fartherred (talk) 19:30, 27 July 2010 (UTC)
Fair play. Only two contentious issues, must be a record for me. :) gonads3 19:52, 27 July 2010 (UTC)

Mars in fiction

If there is an entire "Mars in fiction" article, does the "Mars in fiction" section in this article really need to be as big as it is? Ekwos (talk) 19:47, 6 August 2010 (UTC)

Yes. The information is historically relevant and significant. It likely has a lot to do with the public fascination with Mars.—RJH (talk) 20:07, 7 August 2010 (UTC)
But there is a separate article devoted specifically to the topic. That should reduce that aspect of this article to a brief mention and link to the other article. Ekwos (talk) 18:39, 18 August 2010 (UTC)
The summary policy is covered by WP:SS. It is not mandatory that the topic be reduced to a "brief mention"; only that the subject be summarized.
For most science articles I would agree with you and it is often satisfactory to cover the topic on the various ***** in fiction articles. In the case of Mars, however, the fiction has cultural significance and is worth describing with a modicum of detail.—RJH (talk) 22:37, 18 August 2010 (UTC)
Well, the way I look at it, one of the advantages of the Wiki format is that it is so easy to link to the other article that it allows one to reduce the duplication of info from article to article. Ekwos (talk) 17:09, 19 August 2010 (UTC)
Well, some duplication is necessary to summarize an article, just as some duplication is necessary to satisfy WP:LEDE. The article in its current form satisfies the FA criteria, including that of comprehensiveness in all major facts and details. I consider the fiction to be included in that criteria. Thus I'm not clear that we can come to a compromise here: I want a summary; you want it gone. We'll just have to agree to disagree.—RJH (talk) 18:44, 19 August 2010 (UTC)

Are parentheses (valid)?

I am not bothered enough by any of the other ephemeral features of the Mars hoax statement to revert them, but the parentheses in (valid) must go. --Fartherred (talk) 22:16, 2 September 2010 (UTC)

Yes I agree. The entry contained information redundant with the prior paragraph, and the use of parentheses was not good because they disrupt the flow too much and make it awkward to parse by text readers. The statement about the particular date was trivial and should be dispensed with; the date of the close approach was already listed in the prior paragraph, and is of no further interest. My $.02 anyway. Thanks.—RJH (talk) 18:49, 3 September 2010 (UTC)
I'm not sure what is achieved by even mentioning the hoax. That's all it was, a hoax, feeding off ignorance. Let it starve. HiLo48 (talk) 22:13, 3 September 2010 (UTC)
I will give examples of the proper use of parentheses. To enlarge upon an example used in the article Apposition: My wife (a nurse by training) was able to give first aid at the scene. In the article the appositive was set off by commas. Here I used parentheses. It is a matter of judgment.
At the Grammar Girl web site there is an example of a date marked by the calendar definition and by an event with the two in apposition using parentheses. Here is another example: She made reservations for the anniversary of Bob Newhart's birthday (Sept. 5 ,1929) because he is her favorite actor. Here the date in apposition could not be set off by commas because there is a comma in the date. It could be rewritten: ...Newhart's birthday, the 5th of September 1929, because...so commas could set off the apposition. The Grammar Girl site also shows parentheses used for an aside. However, parentheses are not properly used to isolate an adjective immediately in front of the word it modifies, as with "valid email". Rothorpe suggested in his edit summary on the 2nd of September that parentheses is a singular word and parentheses was used to apologize for the word "valid". If the word valid is true, why would it need an apology? Parentheses are not used to apologize for words in any case. Can anyone state the benefit to the article from the parentheses around "valid"? Without the word "valid" the reader might think a hoax email in 2003 spawned imitation hoaxes, so we should keep that word. I hope we can have a consensus to remove the parentheses around "valid", but I will not act against consensus, even for good grammar.
Eliminating the hoax bit would make the matter moot.--Fartherred (talk) 03:35, 4 September 2010 (UTC)
I leave it to others to decide whether the hoax needs to be mentioned. As a Brit, I normally say 'brackets' for 'parentheses', which perhaps explains why I didn't notice that the word was plural. But the use of parenthesis (sic, singular) to denote a sotto voce aside, as in 'A (valid) email sent in 2003 has over the years spawned hoax emails' is quite normal, though you might not think it encyclopedic. Rothorpe (talk) 12:49, 4 September 2010 (UTC)
No one has stated a benefit to the article derived from having parentheses around the word "valid" nor any meaning of the parentheses. The closest to this was Rothorpe writing that using "parenthesis (sic)" indicated a sotto voce aside. Since he did not indicate the meaning of a sotto voce aside, one is still left to guess at the meaning. The article on sotto voce refers to a story of Galileo Galilei saying "Eppur si muove" sotto voce. Are we to understand that the email referred to being valid might surprise, shock, or offend? Is it a circumstance which we should emphasize, deemphasize, or recognize with pride or shame? The meaning of sotto voce is not clear in the circumstance. WP:MOS#Clarity states that plain English is preferred style for Wikipedia. If there are no objections, I intend to remove the parentheses from the word "valid" again. --Fartherred (talk) 23:15, 5 September 2010 (UTC)

In Our Time

The BBC programme In Our Time presented by Melvyn Bragg has an episode which may be about this subject (if not moving this note to the appropriate talk page earns cookies). You can add it to "External links" by pasting * {{In Our Time|Mars|b00772rr}}. Rich Farmbrough, 03:17, 16 September 2010 (UTC).

JPL fact sheet distances

The JPL fact sheet minimum distances are only valid over a limited range of time. That's fine, but the sheets never say what range is intended, and in fact the range varies wildly. After rounding, Mars comes closer in 3013 (and its opposition distance is less than that as soon as 3092. From Solex 11.0. Saros136 (talk) 10:23, 29 September 2010 (UTC)

The 2003 close approach would have missed that cutoff too, contrary to the deleted sentence. Saros136 (talk) 10:32, 29 September 2010 (UTC)
I do not understand you objection to the deleted text. Mars can come as close to Earth as 55.7 million km at opposition and has an average opposition distance of about 78 million km. What do you mean by "The 2003 close approach would have missed that cutoff too ..."? The text did not refer to a cutoff. A close approach can be closer than the opposition distance in a particular year if that is what you are getting at. The sentence you deleted was supported by the reference. That is what seems important to me. As for the range of time that this statement is true, I expect it is true for a century before and after present. If it is not, can you show me the reference that shows it does not apply in that range.--Fartherred (talk) 14:42, 29 September 2010 (UTC)
The 2003 distance was 55.8, not 55.7 Gm. By cutoff, I mean the 55.75 Gm mark, which would make it 55.7 after rounding. That doesn't happen until 2287. (The fact sheet does not cite any one approach.) The sentence also confuses the opposition distance with the close approach distance, when they are never equal.
The lack of a qualifier in the fact sheet has led some people to think it cites the closest distance ever. This is not true. In fact, the given distance gets beaten badly. It is 54.7 Gm as soon as 8411. The article deals in orbital facts more than a million years from present, in one case, and refers to another close approach 60,000 years away. In this context, having a distance only valid to about 1,000 years is not good enough. Saros136 (talk) 18:41, 29 September 2010 (UTC)
You may be correct that the reported minimum opposition distance in the article was different from the opposition distance of 2003 by one count in the last significant figure. Since I have no reliable source for the opposition distance in 2003 to that accuracy, I will remove reference to the 2003 opposition from the article but otherwise restore the text that you deleted in your edit at 2010 September 29, 10:19:19 hours. It is supported by a reliable source while your statements are not. --Fartherred (talk) 06:10, 30 September 2010 (UTC)
Where did you get the idea that Solex is not a reliable source? Saros136 (talk) 06:29, 30 September 2010 (UTC)

I have never claimed that Solex was not a reliable source. I do not use the program myself. Can you show that Solex disagrees with the article as I have amended it? It is insufficient that reliable sources support your claim. You must also refer to them.--Fartherred (talk) 07:18, 30 September 2010 (UTC)

Sorry if I took it the wrong way. Actually, I did mention in this discussion that is my source. I did not make any claim in the article, there is nothing to cite. Here are some results from the program that I posted last year. Miles Standish, the creator of the famed JPL ephemerides, is mentioned here as calculating 54,593,328.422 kilometers as the distance for the 9943 approach and the closest before 10,000. (Solex gives 54.593357 Gm), proving that the fact sheet's number is only valid over a limited range. Saros136 (talk) 08:15, 30 September 2010 (UTC)
So, do you want to revert my reversion of your edit to get this text out of the introduction and then add to the #Viewing section mention of the 55.7 million km approach in 2287 and the 54.6 million km approach in 9943 with references? --Fartherred (talk) 09:11, 30 September 2010 (UTC)
I didn't see this until after my last edit. I've got to go, but I'll come back to the subject later. Saros136 (talk) 09:30, 30 September 2010 (UTC)
I see you already did delete the text I had previously restored and also deleted some duplication that I had not noticed earlier. Since improvements that I made were in the duplicate section that you deleted, I put them into the section that remained. I will let you add the mentions of the approach distances for 2287 and 9943 since you worked up the reference. As to the opposition distance and closest approach distance never being equal, they can be close enough to be represented by the same number, so for some practical purposes there does not need to be a distinction. Modern measurements have made possible ever smaller distinctions in distance which are not necessarily of interest to the general reader. --Fartherred (talk) 15:49, 30 September 2010 (UTC)
You're right, for some practical purposes there does not need to be a distinction. That doesn't mean it should be ignored in the article, because it's very confusing; the concepts are very different. There have been contradictory statements in the article, because of the misunderstanding. It also leads to a misunderstanding of orbits. Why confuse when we can clarify? It's crucial when records come into play. Further, the most famous distance in this article is the minimum, not opposition, distance of 2003. Saros136 (talk) 04:39, 1 October 2010 (UTC)
Vitagliano claims a future distance of 53.641 Gm. (Ref 107). In the interest of verifiability here are my reproducible Solex 11 results calculated from 2010 to the year 10,000. -- Kheider (talk) 04:04, 1 October 2010 (UTC)