Talk:Olympus Mons

message: In the style of the Wikipedia:Million pool, in which participants attempt to name the day on which the English Wikipedia reaches one million articles, I suggest we all place bets on the timing of the first ascent of Olympus Mons, so that future generations of Wikipedians will be able to laugh at our comically inaccurate predictions. The competition closes to new entries on the day the first manned mission reaches Mars. Nearest person wins eternal fame and a Mars Bar. — Trilobite (Talk) 06:53, 28 Feb 2005 (UTC)
thread_title: First ascent

message: According to charts like these  at Olympus mon's peak the atmospheric pressure is 1/60 average Martian surface pressure and that high altitude cloud cover is still possible, thus Olympus mons is still within the Martian atmosphere. Despite the Martian average atmospheric pressure being .006th  our’s, the much lower gravity at mars allows it’s atmosphere to extend much higher. --BerserkerBen 03:34, 9 May 2005 (UTC)
replies: text: I slightly adjusted your paragraph, in amongst other changes I made to the article like sectioning and moving some paragraphs around.  Didn't change the sense of it, just slightly adjusted the wording and did some copyediting. Worldtraveller 10:21, 9 May 2005 (UTC)
thread_title: Atmosphere of Mars and Olympus

message: Since we havent observed any mountains outside the solar system wouldnt it be just as accurate to describe it as the largest known mountain or largest in the known universe or something like that?
: It would, although this would be a little misleading. Olympus Mons is almost certainly the tallest mountain in the Solar System (whose planets have been quite well explored) but it is almost certainly not the largest in the Universe (where we have only yet been able to detect the mere presence of planets in just a few nearby stars in our own Galaxy, despite the fact that there are likely many billions of stars in our Galaxy alone with planets). To call it the largest in the known Universe might imply that some scientists believe it might actually be the largest mountain in the Universe. It's a bit like referring to the tallest skyscraper on Earth as "the largest in the known Universe" - even if that turned out to be true (who knows if aliens build skyscrapers anyway?) it's overly broad. I'll the "largest in the known Universe" bit from the article. Dr.croft 21:21, 24 August 2007 (UTC)
thread_title:  Tallest in Solar System? 

message: I have some issues with the following factoids given in the text:
The atmospheric pressure at the top is about 2% that of average Martian surface pressure
* The martian scale height is 10-11 km, so I would expect the pressure at the top would be e(-25/(10 to 11)) = 8-11% that at the surface.
if one were to stand on the highest point of its summit, the slope of the volcano would extend all the way to the horizon
*The distance to the horizon is equal to sqrt( 2Rh + h2 ), where R = 3,402 km and h = 25 km. This gives a result of 413km, which is larger than the radius (275km) of the mountain.
Are there some references to back up these assertions? Thanks! :-) — RJH (talk) 22:23, 11 July 2006 (UTC)
thread_title:  Questioning the results 

message: Hello, I don't understand why it is written in the article that from the top of Olympus Mons, you can only see as far as 3 km, when the article cited as reference 4 [Martian Volcanoes on HST Images]... explains that:
"Second, if this same person stood at the top of Olympus Mons (88704 ft) we would find that he or she could see a lot further to the horizon, some 265 miles away, if nothing was in the way"
P.S. Even from the the base of the volcano you could see the first 50 miles of the volcano!!
This is a serious mistake.... huge as the biggest mountain in the Solar system.
:Yes, I seem to have oversimplified (I've attempted an improvement). While it is true that ref 4 is poorly written it is infact correct (as far as it goes) when one understands the text in bold:
::Second, if this same person stood at the top of Olympus Mons (88704 ft) we would find that he or she could see a lot further to the horizon, some 265 miles away, if nothing was in the way
:However, something is in the way - Olympus Mons itself. Because Olympus Mons has shallow slope angles (around 6 degrees) and due to its extent, apart from the scarps at the caldera and the 20 degree collapsed slope to the north, there seem to be few places where one can see far. I tried some Back-of-the-envelope calculations to guesstimate where the furthest views would be:
:*rim of the caldera - the floor 80 km away at the opposite end
:*top of the southeast scarp about 5 km elevation - 180 km looking southeast
:*top of the northwest scarp about 8 km elevation - 235 km looking northwest at the aureole deposits
:*top of the northwest scarp about 8 km elevation - 230 km possibly looking upslope towards the summit (depends on precise profile measurements that I am too lazy to look for)
:Profiles estimated from SPREADING OF THE OLYMPUS MONS VOLCANIC EDIFICE, MARS. P. J. McGovern. See the penultimate figure in http://mars.jpl.nasa.gov/mgs/sci/mola/data1/mola_press.html for a nice profile (measured by the Mars Orbiter Laser Altimeter of Mars Global Surveyor) of the northwest scarp - I guessed the furthest view is at 22.5 degrees north. My improvememt  attempt is probably original research and likely to be inaccurate. -Wikianon 17:07, 27 October 2006 (UTC)
replies: text: Thanks, this explanation has been extremely useful, even if the numbers on the furthest view from the escarpment of the volcano are just guesstimates (I've always imagined there is a good view from there).  But I still have something on my mind... Is it possible that from somewhere on top of the volcano, one could see (even if it is something like an thin line) maybe maybe..just a little bit of the Tharsis bulge or Lycus Sulci or something else? (I know it is impossible to see the slope of the volcano.. but i still have this strange image in my head of a thin line of something at the very furthest horizon). Or more specifically... is the average slope of the volcano enough to counter the effect of the curvature of the surface of the planet... allowing that some point way beyond be visible from the top? 
--193.231.140.68 23:57, 27 October 2006 (UTC)
replies: text:  The Tharsis bulge is on the other side of the planet (separation 170 degrees). No you can't see it from Olympus Mons!
The 'citation required' tags are maddening sometimes. For example: Olympus Mons is a big as Arizona, but a statement that you can only see it properly from space is regarded as 'needing citation'. Surely a moment's thought would suggest the statement is obviously true? —The preceding unsigned comment was added by 213.46.64.159 (talk) 14:06, 19 March 2007 (UTC)
thread_title:  How far can you see from Olympus Mons? 

message: Is the leading image of Olympus Mons in the article the best that we can do?  It's a bit of a sideways glance at the mountain.  An overhead view of the entire mountain (or the caldera) might be better.  Or am I just wanting something that we don't have?  Cheers, --Plumbago 12:02, 7 March 2007 (UTC)
thread_title:  Photograph 

message: Please note that the coordinates in this article need fixing as:
*
mars is a bar, not a planet, tit
ps: i love jesus
I took out the geohack link (replaced with non hotlinked coordinates), as it seems useless.  All the resources on geohack are for Earth, not Mars.  The point gets plotted in the middle of the North Pacific.  I've looked at articles for a few other features on the moon and Mars, and didn't see any coordinates hotlinked.  If there is a good resource for Martian/Lunar maps, hotlinked coordinates would be a nice feature, but I don't know where to link to.
192.104.39.2 (talk) 16:09, 8 October 2008 (UTC)
replies: text: geotag is (now?) pointing properly to mars.  Removing geodata-check tag. Gregbaker (talk) 04:54, 6 July 2009 (UTC)
thread_title:  Coordinates 

message: Nix Olympica ("Snows of Olympus"). Nix meaning snow, I gather? Which language would that be in?Stefansquintet (talk) 18:30, 19 January 2009 (UTC)
replies: text: Ah, it was latin of course :) That's Percival Lowell who first named it thinking there was snow there on that hill on Mars.  —Preceding unsigned comment added by Stefansquintet (talk • contribs) 18:33, 19 January 2009 (UTC)
thread_title:  Nix olympica 

message: I'm currently working on Geology of Mars and Volcanism on Mars articles. If no one minds, I'd like to do some relatively minor edits on this article to make it a little more consistent with mine.Schaffman (talk) 12:33, 6 December 2010 (UTC)
replies: text: The new language is odd: ...shallow slopes (5° or less, on average)... says to me that the average is known not to be more than 5°, but is not known to be less; how can that be? —Tamfang (talk) 19:18, 6 December 2010 (UTC)
thread_title:  Editing this article 

message: If no one objects, I recommend placing location information in a second paragraph in the intro block before TOC. This keeps the more detailed info separate from the general.Schaffman (talk) 11:42, 8 December 2010 (UTC)
thread_title: located on the planet Mars at approximately 18°24′N 226°00′E﻿

message: Actually it's beleived to have begun in Hesperian times, but its bulk is probably Amazonian. No sense quibbling here, though. BTW: Amazonian is a period, not an epoch; there's a difference.Schaffman (talk) 12:46, 6 December 2010 (UTC)
thread_title: Olympus Mons was formed during Mars' Amazonian epoch

message: The references are outdated and based on pre-MOLA estimates. The actual elevation (Plescia, 2004) is 21 km.Schaffman (talk) 13:39, 6 December 2010 (UTC)
thread_title: The central edifice stands 27 kilometres (17 mi) high above the mean surface level of Mars[3][4]

message: They are six nested calderas. To me, pit crater implies something else. I think we should use dimensions and terminolgy given by Carr (2006), p. 51. Schaffman (talk) 14:34, 6 December 2010 (UTC)
thread_title: with six overlapping pit craters

message: The escarpment is actually up to 8 km high because the plains along the base are 2 km below datum (elevation -2 km) in places (Carr, 2006).Schaffman (talk) 15:10, 6 December 2010 (UTC)
thread_title: outer edge consists of an escarpment up to 6 km (4 miles) tall

message: I'm not sure this is strictly true. Why not just say "average slope is less than 5 degrees."? Schaffman (talk) 16:08, 6 December 2010 (UTC)
replies: text: The new language is odd: ...shallow slopes (5° or less, on average)... says to me that the average is known not to be more than 5°, but is not known to be less; how can that be? —Tamfang (talk) 19:18, 6 December 2010 (UTC)
thread_title: ...its shallow slope (2.5 degrees on the central dome, 5 degrees in the outer region)

message: I doubt you could see the opposite rim. Even if you're just talking about seeing the floor of the caldera 80 km away, it's still a confusing comment. If we even need to address this topic at all, I'd recommend just saying that from the surrounding plains, one could see the basal escapment of the volcano. A 5-mile high cliff is pretty impressive in itself ! Schaffman (talk) 15:52, 6 December 2010 (UTC)
thread_title: ...but one could see the far side of the caldera, 80 kilometers away.

message: Why is this paragraph necessary?Schaffman (talk) 16:29, 6 December 2010 (UTC)
thread_title: The surrounding scarp, however, has long views of the surrounding terrain...

message: An occasional misconception by whom? I'd delete this statement. Schaffman (talk) 16:25, 6 December 2010 (UTC)
thread_title: An occasional misconception is that the summit of Olympus Mons is above the Martian atmosphere.

message: I calculate 12% using a scale height of 10 km. This would make the average pressure at the top of Oympus Mons about 0.72 mbar (72 pa), if the zero elevation pressure is taken as 6 mbar.Schaffman (talk) 17:15, 6 December 2010 (UTC)
thread_title: The atmospheric pressure at the top varies between 5 and 8% of the average Martian surface pressure

message: I'd like to see a recent reference for this. According to my reference (Zurek et al., 1992 in Mars; Kieffer et al. Eds.) this statement is false. The Viking infrared imaging spectrometer (IRIS) and the Infrared Thermal Mapper (IRTM) showed that the orographic clouds over Tharsis are composed of micron-sized water-ice particles (p. 860). Schaffman (talk) 20:15, 6 December 2010 (UTC)
thread_title: carbon dioxide-ice cloud cover is still possible at the peak of Olympus Mons, '''though water-ice clouds are not.'''

message: This photo is of the scarp face of a normal fault on the flank of the volcano, not the basal escarpment. Because of the potential for confusion I recommend deleting it. Schaffman (talk) 18:31, 10 December 2010 (UTC)
thread_title: Photo of Scarp

message: Actually I think the evidence for glacial activity is closer to the mountain, on the northwest side at the base of the escarpment. The way this is written now sounds like the aureole itself is a glacial landform, which it is not commonly thought to be (to my knowledge).Schaffman (talk) 18:54, 10 December 2010 (UTC)
thread_title: [Aureole has] gigantic ridges and blocks extending 1,000 km (621 mi) from the summit that show evidence of development and resurfacing connected with glacial activity.

message: A topic of recent research on Olympus Mons is the role of "volcanic speading" in creating its unique morphology. See http://www.sciencedaily.com/releases/2009/02/090203175343.htm. The subject also has astrobiological implications, so I'd like to briefly introduce it in this article. Schaffman (talk) 11:59, 8 December 2010 (UTC)
thread_title:  Volcanic Spreading 

message: Surely it's the tallest known volcano in the Universe, not just the Solar System. 82.46.49.194 (talk) 09:24, 23 February 2011 (UTC)
replies: text: We don't know what volcanoes the Sirian overlords may know elsewhere ... —Tamfang (talk) 01:31, 25 February 2011 (UTC)
thread_title:  Tallest known volcano 

message: : The summit of the mountain has six nested calderas (collapse craters)
This was recently changed to collapsed craters, which I think is less correct: a caldera is a crater created when a magma chamber collapses, not a crater (formed in some unspecified way) which has itself collapsed. —Tamfang (talk) 08:01, 17 March 2011 (UTC)
thread_title:  craters and collapse 

message: There are a couple of problems with this article that I'm not sure how to fix.
First, the lead says that Olympus Mons became the tallest mountain on any world after the discovery of Rheasilvia Mons.  That doesn't make sense.  How did discovering a shorter mountain make Olympus Mons suddenly the tallest?
Second, the info box says Olympus Mons was discovered by Mariner 9, but the lead says it was known much earlier.
Suggestions? Rick Norwood (talk) 13:58, 21 July 2012 (UTC)
replies: text: Re Rheasilvia and Olympus, this has just been garbled through multiple minor edits I think. It's an ongoing problem across a number of articles, as received wisdom has it that Olympus is biggest, and what with Rheasilvia being on Vesta not a true planet, the whole thing has just got pretty confusing. I'll reword this. Re the discovery date, I don't know for sure, but I think you can tell something is "there" using telescopes from the abedo, but it was Mariner 9 that actually clarified that it was a volcano. I'll leave this one to someone who actually knows, though. (If no-one does, I can probably track this down in a reference, but it will take a while!) DanHobley (talk) 14:36, 21 July 2012 (UTC)
replies: text: From looking around, named Nix Olympica (Snows of Olympus) by Giovanni Schiaparelli in 1879. Named, not discovered. Could find any ealier mentions, from a quick scan of google books. Re Mariner 9 in the infobox, is identified a better word. Ceoil (talk) 00:28, 22 July 2012 (UTC)

text: Right, there were no rovers on Olympus Mons. This was introduced in this Dec 15, 2015 edit. The numbers seem to come from this 1997 source, inserted in the same edit. But the source attributes them to the Viking landers, not to "rovers that roamed and climbed Olympus Mons".  Quite some misunderstanding... --Oefe (talk) 22:43, 14 January 2016 (UTC)
thread_title:  Problems with the article 

message: ″It stands almost three times as tall as Mount Everest's height above sea level."
IMHO, "nearly 22 km" isn't really "almost three times" 8848 m. Nearly 22000 m isn't even 2.5 times 8840 m (22120 m), so one can hardly round up to 3. Hence, I think it would be more correct to say "almost 2.5 times as high".--91.89.231.229 (talk) 15:58, 29 March 2013 (UTC)
replies: text: Informational post only without really arguing your point either way: The source of that statement is here. They are using a figure of 26 km "above the surrounding plains" and so 26,000m / 8,848 m = 2.94 or approx 3 times as high. --RacerX11 Talk to meStalk me  16:35, 29 March 2013 (UTC)
thread_title:  Height comparison 

message: "The typical atmospheric pressure at the top of Olympus Mons is 72 pascal, about 12% of the average Martian surface pressure of 600 pascal." But the accompanying comparison table states 0.03kPa i.e. 30Pa, less than half this figure. Accompanying cite states "Standard Pressure Profiles measured by MGS Radio Science team at 27 km (17 mi) range from approx 30 to 50 pascals". Which is correct? --114.77.41.5 (talk) 23:35, 9 March 2014 (UTC)
thread_title:  Atmospheric pressure 

message: The following excerpt is extremely confusing:
  The extraordinary size of Olympus Mons is likely because Mars lacks
  mobile tectonic plates. Unlike on Earth, the crust of Mars remains
  fixed over a stationary hotspot, and a volcano can continue to
  discharge lava until it reaches an enormous height.[16]
The height is limited because of gravity and plasticity of rocks. The
higher a volcano/mountain, the higher the pressure at its base.  When
this pressure reaches the plasticity limit of the rock involved, the
volcano cannot go further up.  Gravity on Mars is about 2.6 times
smaller than on Earth, which explains why the highest volcano is about
2.6 times higher than the highest volcano/mountain on Earth.
The first sentence of the excerpt is OK, though, and the reference
given [16] is not wrong, but it simply says:
  Mars does not have plate tectonics, which causes the magma to build
  a volcano in one location making Olympus Mons so large.
In summary: "so large" is OK; "so high" is wrong.
130.79.10.22 (talk) 09:10, 9 July 2019 (UTC)
replies: text:  Nice spot. DanHobley (talk) 09:29, 4 June 2020 (UTC)
thread_title:  Olympus Mons is not high because of the absence of plate tectonics 

message: The article currently says  and references this source. Unless I'm missing something, that website does not say this: the 3 kilometres is for the view from the base ("First, if we were 6 feet tall and stood at the base of Olympus Mons we would then be able to see the horizon some 2.19 miles away"), and the figure from the summit is the much more respectable 265 miles = 426 km ("if this same person stood at the top of Olympus Mons (88704 ft) we would find that he or she could see a lot further to the horizon, some 265 miles away, if nothing was in the way"). 82.18.206.157 (talk) 10:15, 25 December 2021 (UTC)
thread_title:  Distance of horizon