Talk:List of tallest mountains in the Solar System

Heights
Heights are base-to-peak, as data e.g. at List of mountains on Mars by height not directly comparable to peaks on other worlds. — kwami (talk) 22:05, 18 October 2011 (UTC)
 * The data in the table isn't internally consistent either, though. The example of Olympus Mons is not widely recognized at this height; the figure of 22km is much more widely accepted. To get the 26km figure, as reference [2] does, you have to compare the peak to the northern plains, across Lycus Sulci, and 1000km away. This is much larger than the recognised volcanic edifice, and would be comparable to claiming a height for Everest of 13km, peak-to-abyssal-plain. I'm switching in the lower figure (and will add something to the Olympus Mons page to reflect the problem).DanHobley (talk) 18:18, 22 May 2012 (UTC)
 * Oops, just realised I read the table wrong. This is much less problematic than I thought! (Sorry)DanHobley (talk) 18:19, 22 May 2012 (UTC)

Other possibilities
Crater central peaks on Tethys and Dione and the limb mountain on Oberon may merit inclusion. WolfmanSF (talk) 04:52, 5 July 2012 (UTC)


 * Sure. Sources for any of those? Oberon in particular might be tricky. — kwami (talk) 07:54, 5 July 2012 (UTC)


 * In "Large impact features on middle-sized icy satellites" (2004), Moore et al. claim the Oberon limb mountain is 11 km high. NASA's SSE web site and several others give a figure of 6 km high. So, there's a major disparity in values. I'm not sure of the origin of the second one, or which is currently considered more credible. WolfmanSF (talk) 03:10, 6 July 2012 (UTC)


 * The Voyager pix of Oberon probably aren't good enough to get within a factor of two. We could list the range in this article. — kwami (talk) 09:35, 6 July 2012 (UTC)


 * It turns out the the 6 km height is an older value that goes back to shortly after the 1986 encounter, so I'm going to go with the more recent value, as the Oberon article does also. WolfmanSF (talk) 03:32, 7 July 2012 (UTC)

Who made Rheasilvia a Mons?
According to the Gazetteer of Planetary Nomenclature the IAU does not recognize any feature on Vesta called Rheasilvia Mons. They do recognize the crater Rheasilvia. We can't go around letting anyone but the IAU name solar system features. We're not even sure that Mons recognition will be forthcoming from the IAU – what with the irregular shape of asteroids, it’s hard to define a reference plane from which to measure the elevation of a mountain. If they started having mountains on asteroids, perhaps the entire body of some asteroids could qualify as a mountain.

Anyways until “Rheasilvia Mons” becomes a well defined object, I think we should de-emphasize it from the top of this article. Thrawn562 (talk) 18:15, 5 September 2012 (UTC)


 * I disagree with the general argument that we shouldn't recognize mountains until they are formally named. The fact that the name is not official could perhaps be pointed out in a footnote; alternatively, we might describe it as Rheasilvia's central peak. WolfmanSF (talk) 22:55, 5 September 2012 (UTC)
 * Looking at the USGS site, I don't see many crater central peaks named anywhere, even on the moon. One exception is Aeolis Mons in Mars's Gale Crater (widely, but not officially known as Mount Sharp), but it isn't clear that it is really a classical central peak. So, we might have to wait a long time before Rheasilvia's central peak gets officially named. To me it wouldn't make sense to have a policy of not recognizing impact craters until they are officially named, and I don't see why mountains should be different. Using computer analysis, it shouldn't be terribly difficult to get a correct height for the Rheasilvia central peak based on the ellipsoidal shape of Vesta, although I'm not sure if such has been published yet. WolfmanSF (talk) 00:48, 6 September 2012 (UTC)

Interwikilink information
FYI, it.wiki has decided to transfer the content of this article in it:Mons (esogeologia), due to the ambiguity of definition of a "mountain" in other planets and the need for additional sources to be found or produced in order to show a scientifically correct table. Considering that articles about the definition of "Mons" or a list of Montes exist in different wikipedia versions, and never overlap (fr, it and da have one, while sv and en have the other), maybe you should just consider this quite "confused" situation to define a better (and possibly shared) strategy. I am neutral about who may be more "correct".--Alexmar983 (talk) 14:02, 4 December 2012 (UTC)
 * I don't see any reason why a list of tallest solar system mountains and an article defining or discussing "mons" on extraterrestrial bodies should need to be combined. The list is always going to be a work-in-progress, due to our incomplete exploration of the Solar System. WolfmanSF (talk) 17:31, 4 December 2012 (UTC)
 * me neither, but welcome to the italian wikipedia... not all the wikis accept lists which are too much "work in progress" (I personally do not support that vision too, but they do this way). I mean, I think you should keep the list of course so other wiki can copy it they want, but if you want to connect now to the other wikis maybe you should create another page more focused on the definition of "mons" besides the simple list, because many wikis do not allow to link between lists and normal articles, only lists can be connected to lists. This would help to gather faster all the information necessary for a less ambigous definition, and avoid asymmetries of interwikilinks. I can tell you, the debate on the topic was quite complex with many people stating that no clear source could be found for a correct definition of the height of a "mons", the comparison of that value with the height of a mountain on the earth where there is an ocean, and the limit of the size of the body on which such height represent a meaningful value. If you try to write a page describing a "mons", than you may need some source to address these questions, and those source may be useful for other languages too. As a job, I fix the asymmetries of interwikilinks and although there are situations in which they cannot be avoided it would be nice to prove that sometimes they can be addressed before they propagate. If you do a page with the definition of mons in addition to this list than every language will have the option to copy that page, this one or both. if you don't, some languages (the very small ones probably) will follow you as the big wikipedia and just copy your list, other languages will follow fr.wiki and it.wiki focusing on the definition of mons and at that point comparing how different wikis have addressed this topic will become more and more difficult because there will be two blocks of non-communicating or partially communicating (in just one direction) interwikilinks. Now, it.wiki does not want to keep both pages (one with the definition of mons, and one with a clear "work in progress" list), if I understood it right they just decided to put "some" values in a table "for comparison" that they were clearly defined as "montes" in many different sources, but they decided it is too risky to have one page-list. It is a pity, there would have been at least one "big wiki" with both options, and this would have helped. For examples, in its articles about "mountains" on other planets en.wiki link to Mountain, where the mountains on other planets in the solar system are cited only in the introduction, but the rest of the article is earth-centered. Other wikis consider misleading to talk about (for example) orogeny in general focusing on the process as happened on the hearth. So they decided that a more specific entry on the topic was necessary. I am not saying someone is 100% right here, but for sure "we" are adopting different strategies and it is better to know that. --Alexmar983 (talk) 22:19, 4 December 2012 (UTC)
 * OK, I have created a stub article, Mons (astrogeology). WolfmanSF (talk) 03:17, 5 December 2012 (UTC)
 * thank you very much, this would encourage a more harmonic development of the topic. Fixing these asymmetries is almost impossible after some years and you have no idea how much I appreciate people that understand the "problem".--Alexmar983 (talk) 13:54, 5 December 2012 (UTC)

Base-to-peak
"Heights are given base-to-peak, as there is no non-arbitrary equivalent to height above sea level on other worlds." – That's a given. But it implies that the "base" of a mountain can be non-arbitrarily defined. Determining the position of Everest's highest peak is easy in theory (so simply an engineering problem), but determining the position of its lowest base seems to me rather to be a matter of definitions? 85.226.204.42 (talk) 12:16, 20 June 2013 (UTC)
 * Yes, there is no exact universal definition of "base", although the concept is widely used. Note that for Everest, the height listed inside the table is 4.1 km, the mean of the lowest and highest base values. WolfmanSF (talk) 14:43, 20 June 2013 (UTC)

The picture is misleading and will be removed. Mauna Kea, as compared to worlds without ocean, is base to peak where the base is well below sea level. This is reflected in the table correctly (though with a note) but the picture ignores that fact. 66.190.94.33 (talk) 04:08, 29 June 2015 (UTC)
 * Look again, the picture does show Mauna Kea's undersea base. WolfmanSF (talk) 07:29, 29 June 2015 (UTC)

Featured on Smithsonian
It would appear the idea of this list was copied at Smithsonian, though they used different height estimates in some cases. — kwami (talk) 01:43, 2 September 2015 (UTC)

Request edit on 12 August 2016
Add these please:

— 2601:183:4000:D57A:E532:F558:2BA1:2602 (talk) 01:29, 12 August 2016 (UTC)
 * Thank you for your suggestion. It is unlikely that we will be able to use that image, as it is likely copyrighted (due to legal reasons, we must assume that images on the Internet are copyrighted unless the author explicitly waives their rights). Altamel (talk) 02:45, 12 August 2016 (UTC)

Comparison of Olympus Mons and Rheasilvia's central peak - invalid because of differing accuracy?
The height of summit above base of Olympus Mons has been measured by MOLA/NASA to be 21.9 km to the nearest 0.1 km. I'm aware of source references that give the height of Rheasilvia's central peak as 22 km, but this is only to the nearest 1 km. Where is the evidence that Rheasilvia's central peak is not actually between 21.5 and 21.9 km to the nearest 0.1 km, that is, actually lower than Olympus Mons? I think that until the height of Rheasilvia's central peak has been measured to the same degree of accuracy as Olympus Mons, accurate comparisions between the heights of these two mountains are suspect, unwise and invalid. GeoWriter (talk) 18:05, 31 October 2018 (UTC)
 * We don't imply that the two measurements have the same degree of accuracy, do we? We aren't claiming that one is taller than the other, which is probably not possible at this point. Height above base is (unfortunately) not generally something that can be measured to the same degree of accuracy as height above seal level, because "base" does not have a similarly precise definition. Not sure what the actual problem is here. WolfmanSF (talk) 19:23, 31 October 2018 (UTC)

A reader would see, from the table in this article (which is sortable by height), that the height of Rheasilvia is 22 km and the height of Olympus Mons is 21.9 km and I am sure many readers would conclude that Rheasilvia's central peak is higher than Olympus Mons, making it the tallest mountain in the Solar System, but this may only be an artifact of measurement accuracy and, as you observed, the article does not mention (degree of) accuracy. Editors are, however, using the data in this article to conclude that the central peak of Rheasilvia is the tallest mountain in the Solar System, without considering the accuracy of the measurements, and editing the Rheasilvia and Olympus Mons accordingly, for example, User:Sleyece's edit of 31 October 2018 at 04:12 of the Rheasilvia article. My comment is intended to address this and perhaps prompt the addition of an explanatory note about accuracy in this list article. GeoWriter (talk) 20:55, 31 October 2018 (UTC)
 * I see your point. I've added notes to clarify the false impression created by the order in the table when sorted by height. I hope that solves the problem. WolfmanSF (talk) 21:57, 31 October 2018 (UTC)
 * If new data becomes available the article will change accordingly. That is run of the mill building of an Encyclopedia. -- Sleyece (talk) 23:44, 31 October 2018 (UTC)

WolfmanSF, your change to the notes in this list article improve the article, thanks. Sleyece, I look forward to new data becoming available in the future but my point is that current data do not explicitly support the premature claim about Rheasilvia's central peak being the tallest peak in the Solar System. GeoWriter (talk) 10:35, 1 November 2018 (UTC)

Note for Mt. Everest
One might logically think that simply mentioning that it has the highest elevation above sea level explains why it is listed. Sadly, that is not true. I added that note when I found that another web site based on this article (there are a number of these) was listing Everest as the Earth mountain with the second highest base-to-peak height on land. While I would like to dispel this notion by listing the actual mountain that is in second place in this category, that piece of information is hard to come by. WolfmanSF (talk) 15:45, 13 March 2019 (UTC)
 * I'm not quite sure that I understand - a website posted a piece of false information, and that is reason enough that Wikipedia should change their articles? Please tell me that's not what you wanted to say. 91.10.14.249 (talk) 17:16, 13 March 2019 (UTC)
 * Yes, a website posted a piece of false information based on a misinterpretation of this article. That is reason enough to edit our article to try to ensure that no others are similarly confused. WolfmanSF (talk) 17:45, 13 March 2019 (UTC)
 * That's ridiculous. We can't amend each article each time somebody misunderstands something. The article does not contain a shred of a hint of what the other site conjured out of thin air. There is no reason to do anything about it.
 * The current version is clumsy, and I'm not sure adding justification to every or any entry in the table could be anything but clumsy.
 * We can't prevent that people dream up information. The qualifier is superfluous and should go. 91.10.14.249 (talk) 22:09, 13 March 2019 (UTC)
 * Mt. Everest is actually the only peak in the table that is not included on the basis of its base to peak height. So, from my perspective, the misunderstanding was not ridiculous and the explanatory note is not out of place.WolfmanSF (talk) 23:14, 13 March 2019 (UTC)
 * Now I'm not really sure how to respond to that. Have you even read the version I propose? Here is an excerpt: "highest elevation (8.8 km) above sea level". That's the explanation. Did you already forget? Did you read the article at all? 91.10.15.50 (talk) 19:21, 14 March 2019 (UTC)
 * Yes, indeed. This is, from my perspective, a lot of complaining about something that doesn't deserve it. Now I've moved the qualification to a parenthetical phrase; hopefully, that's an improvement. WolfmanSF (talk) 21:11, 14 March 2019 (UTC)

Split highest and tallest
We have List of highest mountains on Earth based on the elevation above the geoid (mean sea level as if it were extended inland by fictitious canals). We also have List of mountain peaks by prominence based on the only rigorous way of defining "peak-to-base" height, which is topographic prominence. The present article, List of tallest mountains in the Solar System, mixes the two types of vertical superlatives, Category:Highest things and Category:Tallest things. The situation is a bit better for Mars, because it has its own geoid (the areoid), so List of mountains on Mars by height is well defined as a member of Category:Highest things. That should explain why some of the values quoted here differ from reliable sources, such as fgnievinski (talk) 18:32, 30 November 2019 (UTC)
 * Actually, so far the article is based exclusively on "tallest", not "highest"; it contains no data related to height above some mean elevation. Now, how did you determine that the Smithsonian article is an accurate source, when they don't cite their own sources? WolfmanSF (talk) 09:02, 1 December 2019 (UTC)
 * Topographic prominence is not equivalent to peak to base height. By definition, the base is a local feature, whereas prominence may be based on a very distant col. For example, from the article, "The key col for Aconcagua, if sea level is disregarded, is the Bering Strait at a distance of 13,655 km". In order to list peaks by topographic prominence, we would potentially need a digital terrain model for the entire body, which in many cases we don't have. Peak to base height is neither elevation above a defined height nor prominence. It is, however, the best we can do in many of these cases. It is also a statistic of interest in its own right, even if not so precisely defined. WolfmanSF (talk) 22:19, 30 November 2019 (UTC)
 * How available prominence data is for peaks on other worlds may be an issue. My impression is that these values are of greatest interest to alpinists, so there may be little motivation to calculate the values for other worlds. Regarding height above some defined mean elevation, those values may be of interest on their own, but comparing the values from different worlds may be like comparing apples and oranges. A world with great total vertical relief, such as from deep basins, may acquire large values without possessing particularly tall peaks. WolfmanSF (talk) 09:02, 1 December 2019 (UTC)

Ambiguity
Different distinct interpretations of base to peak height are possible. Consider a world with the following total topographic relief (cross section of a great circle). It has half the world at low level, half the world intermediate height, and one mountain range with some peaks:

Here you have two distinct choices for the base, the plain on the left side of the mountain range or the plain at the right side of the range. Base to peak height is ambiguous in such cases.

Gollem (talk) 08:01, 13 February 2020 (UTC)
 * I would imagine that in such a case, some sort of calculation of "average base elevation" would be attempted. However, this is a contrived situation. In general, the definition of "base height" is simply imprecise (vague), not ambiguous. WolfmanSF (talk) 09:01, 14 February 2020 (UTC)

Reflection of the total topographic relief?
The sentence "such elevations [above an equipotential surface or reference ellipsoid] may be more a reflection of the total topographic relief on a world than the properties of individual peaks" gives the wrong impression that height above an equipotential surface doens't give a representative comparison of peak heights. If that would be the case, we wouldn't be using a geoid at MSL height on Earth for measuring heights. The explanation "total relief is ~20 km on the Moon and on the Earth, ~30 km on Mars; this automatically tells you that the highest peaks by elevation on these worlds are likely to be taller than those on smoother worlds, regardless of their respective base to peak heights" by WolfmanSF, doesn't make sense to me, as it applies on base to peak heights too. Can you please elaborate this explanation or try to rephrase the sentence?

Gollem (talk) 08:21, 13 February 2020 (UTC)
 * My comment was intended to be a general one regarding elevations measured in relation to any global reference level. Consider a planet like the Earth; if there were exactly 20 km of total relief, you would automatically know that the difference in elevation between the highest peak and the deepest trench was 20 km, regardless of the individual topographic profiles of those two features. The peak might have a base on a very high plateau, on a plain close to sea level, or even be below sea level if it was on an island. Similarly, the rim of the trench might be situated in a very deep abyssal plain, or be at a much shallower level. So, if you are interested in the properties of the individual topographic features, their elevations relative to a reference level may not be very informative, and could be highly misleading. WolfmanSF (talk) 09:14, 14 February 2020 (UTC)

Thanks for your clear explanation. You are right about that. On the other hand one can argue that base to peak height is misleading: if a hypothetical aquaduct was build between Mauna Kea and Mount Everest, then water would flow from Mauna Kea to Mount Everest (while Mount Everest has a lower base to peak height). Or, on an world without water, it would mean that a vehicle (like a mars rover) would have to drive more uphill than downhill to get from a peak with a higher to a peak with lower base to peak height. I think this explains why peak to base height and height in relation to a global reference surface are both used as a measure, because both have their advantages and disadvantages. If we want to explain the differences between these two measures in the article, then the advantages and disadvantages of both measures should be treated. However, I think this would be beyond the scope of this article. Do you agree? Gollem (talk) 16:57, 14 February 2020 (UTC)
 * There are other articles which list tallest mountains by elevation on Earth and Mars; we also have lists for the Moon and Io in terms of base to peak height. The list for Earth also gives prominence. Since this is a list article, I agree it probably isn't the best place for a detailed discussion of the various measures of mountains. WolfmanSF (talk) 08:50, 15 February 2020 (UTC)

Exclusion of crater rims
Why are peaks on crater rims of the moon excluded? And does the reason to exclude them not apply on other worlds? Gollem (talk) 03:58, 6 September 2020 (UTC)
 * Crater rims, being circular elevated features, are not themselves mountains, so whether there is any basis for treating a more elevated portion of a rim as a peak is not clear, particularly if its mechanism of formation is not obviously different than impact. As far as I'm aware there's no tradition of naming or regarding rim prominences as peaks. This was mentioned under the Moon mainly because I have a good example at hand. WolfmanSF (talk) 05:56, 6 September 2020 (UTC)

The formation process as well as the absence of a name for a peak should be completely irrelevant for inclusion in the list. On earth crater rims are considered mountains. A tallest point is on a rim is a peak and should be mentioned if it is the tallest. Gollem (talk) 18:22, 6 September 2020 (UTC)
 * A crater rim per se is not considered a mountain. Show me a source that says otherwise. Given that it is not possible for a rim to have perfectly uniform elevation, there will inevitably be taller and lower sections of the rim, as well as a highest point. It sounds like you're saying that the highest elevation on every crater rim should be listed as a peak, which is nonsense. WolfmanSF (talk) 20:04, 6 September 2020 (UTC)

That is your personal opinion. There is no concensus for that point of view. It certainly does not agree with what is witten here: Mountain. No nonsense. Luckely we are only listing the tallest peaks here, so we only have to mention crater rims if these very tall. Gollem (talk) 20:53, 6 September 2020 (UTC)
 * If crater rims were generally considered to be mountains, you should have no trouble finding multiple sources that state that. My view is consistent with the opening sentence of Mountain; the circumference of a crater is not a "limited area, usually in the form of a peak". Regarding placement of the note, I don't feel we have enough material for a general discussion of crater rims at present. We have one interesting example, so it doesn't hurt to park the note under "Moon" for now. If someone gathers more material in the future, that could change. WolfmanSF (talk) 21:05, 6 September 2020 (UTC)