Talk:Olympus Mons

Second largest? Second tallest?

The intro describes Olympus Mons as second to Earth's Tamu Massif and Vesta's Rheasilvia in size and height, but both of those articles give figures that they are smaller than Olympus Mons. Craig Butz (talk) 17:45, 15 September 2019 (UTC)

Also, is it right to compare a moun

Untitled

Height of Olympus Mons is given in this article as 27 km, but was given as 25 km in the [[Mars (planet) article. I have adjusted to make both articles read the same. BUT there is no mention of how these different heights are calculated. As there is no "sea level" on Mars, as there is no sea of free water, what height datum is used? On Mars is the height above mean surface level used or is the height based on elevation above surrounding landscape? I understand Olympus Mons sits in a depression 2 km below mean surface level - this would account for the 2 km discrepancy between the articles. -- kiwiinapanic 09:18 12 Jul 2003 (UTC)

According to the Mars Team Online the measurement of elevation is from the mean. Just as you suspected. I would go with that until somebody has a more authoritative answer.

http://quest.arc.nasa.gov/mars/ask/terrain-geo/Lowest_Elevation_on_Mars.txt

mirwin

Anyone have any idea what height Everest would be if calculated from Earth's land-surface mean? It might make a more accurate comparison for the relative size of the features? --Malcohol 13:55, 15 March 2006 (UTC)

My copy of The New Atlas of the Universe lists the height as 25 km above surface level. --Dante Alighieri 10:06 12 Jul 2003 (UTC)

Average surface level or local surface level? ;) -- Oliver P. 10:18 12 Jul 2003 (UTC)

Hehe, I forgot to type that in. Mean. --Dante Alighieri 20:01 12 Jul 2003 (UTC)

---

So - how big is Olympus Mons?! I found a variety of answers:

[1]	29 km above base	600 km diameter
[2]	29 km high	500 km dia
[3]	27 km high	700 km dia
[4]	27 km high	>600 km dia
[5]	27 km above base	600 km dia
[6]	27 km above datum
[7]	27 km above datum
[8]	26 km above base	500 km dia
[9]	25 km above base	800 km dia
[10]	25 km high	700 km dia
[11]	25 km above base	624 km dia
[12]	25 km above base	600 km dia
[13]	25 km above base	550 km dia
[14]	<25 km above base	600 km dia
[15]	25 km above datum
[16]	24 km above base (to caldera?)	550 km diameter	2.4-2.8 km deep caldera
[17]	24 km above base	>500 km dia
[18]	24 km high	480 km dia
[19]	24 km above datum
[20]	22 ±1 km above base
[21]	22 km above base
[22]	21.618 km high
[23]	21 km high	600 km dia
[24]	21 km high	600 km dia

The bit about Olympus standing "in a two-kilometre-deep depression" is wrong - see the topo map o' Mars - though it makes a difference if you measure the "height from the base" on the east or west side. --wwoods 08:14, 7 May 2004 (UTC)

First ascent

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)

• 3 September 2048 — Current plans are to return to the Moon around 2018; plans to go to Mars will start after 2020. Now given NASA's current track record, we can expect some serious delays. However, with the current rate of technological achievement and the possibility for a technological singularity within the next...oh...century, I think humans will ascend Olympus Mons around 2050 or so. Thus, Trilobite might have a pretty good estimate. Another reason for this is because private endeavors will likely pave the wave for such a feat. Let's compare technology from 1995 to 2005. We went from basically no commercialization of space, to a relatively flourishing industry. We have SpaceX, Virgin Galactic, etc. Youthful startups, but with some serious goals of suborbital and orbital fligths. I think the industry will begin booming and with an increase in public support for space exploration brought on partly by the Vision for Space Exploration and mostly by private interests, we may see man ascend Olympus Mons somewhere around this timeframe. Seems to be early estimates, but I am using that exponential technology curve (which leads up to the theoretical technological singularity). I do not think we should use current paces for determining such things. I would bet that the aforementioned will happen (as far as private endeavors arousing public support). Just my thoughts. --Marsbound2024 04:50, 23 December 2005 (UTC)
• 29 May 2053 — Trilobite (Talk) 06:53, 28 Feb 2005 (UTC)
• 19 October 2067 bob rulz 11:54, Jun 21, 2005 (UTC)
• July 16, 2069. A Chinese astronaut, trying to do Neil Armstrong one better. Marskell (talk) 12:43, 6 February 2008 (UTC)
• 5 April 2071 I call dibs. Me and my spunky grandkids will achieve the first ascent on my 70th birthday (or as soon as feasible).
• 9 July 2078 — same day Wikipedia reaches 5 million articles :) Worldtraveller 12:46, 3 Mar 2005 (UTC)
• 17 March 2087 — the day I would supposedly turn 100. I doubt I'll be alive then so if by some weird chance I win, give the Mars Bar to my pal Ashleigh. 青い(Aoi) 05:10, 9 May 2005 (UTC)
• 22 May 2087 is my guess! The QBasicJedi 08:12, 22 June 2006 (UTC)
• 21st August, 2147 — . We need more time to accomplish such a feat. While it is clear that the rate of technological development is increasing, the track record of humans attempting to predict development in this field is dubious. Think of "2001: A Space Odyssey." It was not out of the question to Americans in the 60s that we would be traveling to the outer solar system 14 years ago. As we know, this never happened and will likely not happen for a very, very long time. (Unless a FTL drive is invented! Hey, a girl can dream.) Now think of all of the additional challenges presented by a summit attempt. Enough oxygen would have to be brought along to provide for the team for what we can only assume would be at least a month long journey - and not only supplemental oxygen as on Everest and K2 and other 8000 meter peaks, but all of the necessary air. The climb would also be far more arduous than treks of similar lengths on Earth, and the likelihood that the party would have to turn back because of injury is extraordinarily high. In addition, the party would have to move constantly because of resource issues, while in contrast climbers on Earth's tallest peaks can remain on the mountain in one place for several weeks waiting for the perfect conditions for a summit attempt or at least recuperating. It is likely that there will be several failed summit attempts before the first successful one. Let us also not ignore the fact that the first many years of human settlement on Mars will likely be characterized by repeated mishaps, low morale, and low populations. So, even if a substantial settlement is established on Mars within the next few decades, it will be a long time before any Martians say, "Hey, let's climb a huge f****** mountain!" Massachusettsan (talk) 11:22, 9 February 2015 (UTC)
• Never — The human race will be replace by cybrogs, robots, ect, thus it's unlike "man" will ever ascend Olympus (i'm serious), perhaps some form of human successor or transhuman being will climb it though, if i'm wrong it will at least make a good laugh.--BerserkerBen 03:34, 9 May 2005 (UTC)

For the moment, I'm not putting in a guess. However, I feel I might add that it is highly unlikely that NASA will have the first manned mission to Mars be on Olympus Mons. SkepticBanner (talk) 14:55, 17 January 2008 (UTC)

WHY IS THERE A CLIMBING SECTION IN THIS PAGE? can someone delete the section about the aliens and humans that climbed the mountain... —Preceding unsigned comment added by 68.179.122.177 (talk) 16:46, 20 July 2009 (UTC)

Atmosphere of Mars and Olympus

According to charts like these [25] 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)

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)

Exosquad

Look, entries for Venus, Neptune, and many of the other planets all have sections for their appearence in science fiction and films. It is not unreasonable that the exosquad entry be in this article. I have shortened it to a mere sentence. Please stop editing it out.

Geographical coordinate link doesn't work

18°N 226°E

It says Error:Out of range

Yaohua2000 09:44, 4 November 2005 (UTC)

Was not the user you reverted correct, that by definition longitude can't be in excess of 180? Marskell 12:20, 7 November 2005 (UTC)

See the last paragraph in Timekeeping_on_Mars#Keeping_track_of_time_of_day for details about geographical coordinate used on Mars. — Yaohua2000 12:28, 7 November 2005 (UTC)

should the coordinate link to Google Mars?Liaocyed Feb, 2007]

Tallest in Solar System?

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)

In Fiction

World Traveller, I recall you opposed the In Fiction section of this article when I initially added it some months ago, but you relented and it's done nothing but grow since then with further additions from other users, which is an indication this is an area of interest. I don't think outright deleting it was appropriate. As I noted before, virtually every article on a major body of space (all the planets, basicly) has a section on its presense in Fiction. As perhaps the single most notable feature of any solar object, Olympus Mons also should be deserving of this acknowledgement. As the various entries show, Olympus Mons is a popular setting in various fictions.

If you are truly vehemently opposed to the section, then a compromise would be a seperate article. Most of the planetary bodies have seperate articles for their presense in Fiction, because they are usually quite large entries (Mars, especially). Olympus Mons' In Fiction section is not even half as large as any of the planet's In Fiction entries, but a seperate article could be created. However, I do not think it's necessary to seperate. Elijya 15:03, 18 May 2006 (UTC)

Titan's recently got big enough that it was removed to a separate article. I agree that the information should not be deleted, and would support either leaving it here for now or going ahead and moving it to a separate article.--Curtis Clark 15:48, 18 May 2006 (UTC)

What I think is that 'in fiction' or 'in popular culture' sections can be good, but very rarely are. What is always bad is a list of programs in which a topic has appeared - these tell the reader nothing at all about the subject of the article. What's far far better is explaining the impact something has had on popular culture. A model example is in The Scream. I don't think that the 'xx in fiction' sections that exist for a lot of planets at the moment are worthwhile at all - they pander to science fiction enthusiasts and detract from the authoritativeness of the articles, in my opinion. They're also never prose, always lists, and lists should be avoided unless they are absolutely necessary because 'brilliant prose' is always the aim. When I rewrote Mercury recently I took out the 'in fiction' section before the FAC nomination and no-one complained at all.

Mars generally would warrant a popular culture section, due to the extremely deeply held belief that it was inhabited, things like the face, canals, war of the worlds, etc etc. These things have widely influenced the public's interest in Mars. But it should be descriptive, and not just a list. Olympus Mons specifically I do not think deserves the same treatment. I can't think of any fiction or appearance in popular culture that can genuinely be said to have influenced general public understanding of it. A line in the article to say the mountain has been a popular setting for sci-fi would more than suffice - if it can be cited from a reputable source. Worldtraveller 21:24, 18 May 2006 (UTC)

Mercury's In Fiction section was given its own page, so obviously there were interested parties who wished to save the information. The fact that YOU don't think an article or section is "worthwhile" does not end the discussion, as wikipedia is a community. And that community has repeatedly decided In Fiction articles or sections are worthy of being placed here. Elijya 01:02, 19 May 2006 (UTC)

I've nothing against "In fiction" lists despite they're hardly encyclopedic. However, I'm not entirely convinced that every surface feature etc. needs own section. In my option, fiction sections in Mars surface feature articles should be merged into the main Mars in fiction article. Even better, that article could be splitted into a real prosaic encyclopedic article and the simple list could be moved into a list page.--JyriL ^talk 10:53, 19 May 2006 (UTC)

Olympus Mons is arguably not just any surface feature. But I like the idea of combining with the Mars in fiction article, as a subsection. This article could then link to the subsection.--Curtis Clark 13:54, 19 May 2006 (UTC)

A sub-section on the Mars In Fiction page would work. Elijya 17:40, 19 May 2006 (UTC)

Questioning the results

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[26], 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)

Verfication tag

It seems like the following data points are seen as questionable: height and diameter, horizon and the atmospheric data. If we could get citations for these data points, preferably from NASA or another space agency, that would be great. Kerowyn ^{Leave a note} 22:48, 1 October 2006 (UTC)

I've bracketted the atmospheric pressure to 30 to 50 Pascal, using the Nasa MGS data at stanford.edu, but assuming 27 km summit height. The stanford data does not have a datapoint right on the summit so I looked at several datapoints in the vicinity and elsewhere on the planet, and read off the pressure from the MGS graph, after subtracting the surface elevation from 27km. Some of the sigma errors are around 5% and my own reading method probably introduces another 5% error, but I noticed the seasonal/diurnal variation was even greater. I also saw that when the pressure is 50 Pa at Mons' 27 km, it is around 65 Pa on Mons caldera floor at 24 km. The 27 km comes from the quest.nasa links (although the German article has 26.4km but no online source). Mons' diameter depends on how it is measured, the tnni.net source gives it 624 km. I removed the mention of Mons sitting in a 2 km depression (also seen in the French article) as it looks more of a shelf next to an even deeper depression of 4 km to the west.

NASA states "the 0-km line is defined at the 6.1 mbar level in the atmosphere", but the same NASA source mentions Hellas is at 4 km below the reference level, while at the same time the Nasa MGS Radio Science data clearly shows Hellas depths hovering around 7km below the "standard martian reference surface (geoid)", so something's wrong somewhere. Is the geoid 3km above the 0-km line? Lastly, I have made similar corrections to Hellas Planitia and Pavonis Mons, but added a verify tag on Hellas.-22:02, 2 October 2006 (UTC)

How far can you see from Olympus Mons?

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][27]... 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)

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)Mihai

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).

Photograph

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)

A full-profile pic (taken from an orbiting spacecraft off above the horizon, one imagines) would be a good addition to this article. Anyone know where/if one is? --Piledhigheranddeeper (talk) 17:08, 22 December 2008 (UTC)

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)

geotag is (now?) pointing properly to mars. Removing geodata-check tag. Gregbaker (talk) 04:54, 6 July 2009 (UTC)

Nix olympica

Nix Olympica ("Snows of Olympus"). Nix meaning snow, I gather? Which language would that be in?Stefansquintet (talk) 18:30, 19 January 2009 (UTC)

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)

Editing this article

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)

located on the planet Mars at approximately 18°24′N 226°00′E

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)

Olympus Mons was formed during Mars' Amazonian epoch

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)

The central edifice stands 27 kilometres (17 mi) high above the mean surface level of Mars[3][4]

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)

Actually, the volcano is 21 km above datum (zero elevation). The mean surface level can (and probably is) different. This needs to be fixed. Dang, I just want to make a few changes and all these other quibbling things pop up. Schaffman (talk) 13:07, 7 December 2010 (UTC)

with six overlapping pit craters

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)

outer edge consists of an escarpment up to 6 km (4 miles) tall

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)

...its shallow slope (2.5 degrees on the central dome, 5 degrees in the outer region)

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)

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)

You're right. Let's just say the average slope is 5 degrees. I have a reference. Schaffman (talk) 20:21, 6 December 2010 (UTC)

...but one could see the far side of the caldera, 80 kilometers away.

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)

The surrounding scarp, however, has long views of the surrounding terrain...

Why is this paragraph necessary?Schaffman (talk) 16:29, 6 December 2010 (UTC)

An occasional misconception is that the summit of Olympus Mons is above the Martian atmosphere.

An occasional misconception by whom? I'd delete this statement. Schaffman (talk) 16:25, 6 December 2010 (UTC)

The atmospheric pressure at the top varies between 5 and 8% of the average Martian surface pressure

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)

carbon dioxide-ice cloud cover is still possible at the peak of Olympus Mons, though water-ice clouds are not.

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)

Photo of Scarp

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)

[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.

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)

Volcanic Spreading

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)

Finished geology discussion except for edits and adding references here and there. Schaffman (talk) 17:04, 10 December 2010 (UTC)

Tallest known volcano

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)

We don't know what volcanoes the Sirian overlords may know elsewhere ... —Tamfang (talk) 01:31, 25 February 2011 (UTC)

craters and collapse

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)

Problems with the article

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)

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)

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)

Re: Description. The article mentions the soil composition as measured by rovers that roamed and climbed Olympus Mons. Which rovers? When? I am unaware of any rover missions anywhere near Olympus Mons. — Preceding unsigned comment added by 65.129.132.48 (talk) 12:53, 14 January 2016 (UTC)

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)

Hi all- I'm just reading this article before giving a Mars show and I'm brushing up on my mars knowledge. I noticed that the last section about possible impact origin seems to have been written by one individual. Scientific merit aside, it appears to be an angry rant trying to discredit the volcanic theory above, not a discussion about the merits of each theory. — Preceding unsigned comment added by 71.58.102.13 (talk) 18:38, 13 July 2016 (UTC)

Height comparison

″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)

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 me^{Stalk me} 16:35, 29 March 2013 (UTC)

Atmospheric pressure

"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)

Impact origin hypothesis

Hi all- I'm just reading this article before giving a Mars show and I'm brushing up on my mars knowledge. I noticed that the last section about possible impact origin seems to have been written by one individual. Scientific merit aside, it appears to be an angry rant trying to discredit the volcanic theory above, not a discussion about the merits of each theory. — Preceding unsigned comment added by 71.58.102.13 (talk) 18:38, 13 July 2016 (UTC)

This section of the Wikipedia article on Olympus Mons is based on a hypothesis described by William B. Hamilton in his paper Terrestrial planets fractionated synchronously with accretion, but Earth progressed through subsequent internally dynamic stages whereas Venus and Mars have been inert for more than 4 billion years in Foulger, G.R., Lustrino, M., and King, S.D., eds., (2015) The Interdisciplinary Earth: A Volume in Honor of Don L. Anderson, Geological Society of America Special Paper 514 and American Geophysical Union Special Publication 71, doi:10.1130/2015.2514(09), http://www.mantleplumes.org/DLABook/Hamilton2015.pdf.

Hamilton's paper is only a year old and probably too recent for the geological community to have reacted to its ideas and assess whether or not the scientific consensus should shift towards it or not. Wikipedia follows and reports the scientific consensus. Wikipedia does not lead or direct scientific thought. Wikipedia is not a scientific newspaper or a scientific hypothesis soapbox. My Google searches show only a few copies of this paper on the web, and no other papers which cite this paper. Does this, therefore, suggest that this bolide hypothesis is still a "fringe theory" (WP:FRINGE) and that the several paragraphs in the current version of Wikipedia's article on Olympus Mons give undue weight (WP:UNDUE) to this hypothesis? I believe it does.

Also, I get the impression that all paragraphs in this section of the Wikipedia article, except the first paragraph, could perhaps be original research (WP:ORIGINAL), using two or three primary sources (WP:PRIMARY), hung onto Hamilton's hypothesis.

I suggest that the first paragraph should be kept because it concisely states that an alternative, bolide, hypothesis has been proposed, but I suggest that the rest of this section should be deleted. GeoWriter (talk) 15:14, 14 July 2016 (UTC)

I have removed all the text from this section of the article, except the first paragraph. GeoWriter (talk) 14:01, 22 July 2016 (UTC)

Section was expanded again by IChiloe who seems to edit only on Hamilton and related articles. Possible COI? I've tagged section as giving this view undue weight for exactly reasons above. Ravensfire (talk) 19:03, 19 November 2016 (UTC)

In the truncated one-paragraph version, the Impact Origin section lacked content; 2nd & 3rd paragraphs needed to briefly describe evidence (from H15 paper). It is a heterodox theory worth evaluating substantively from evidence. About which I would welcome discussion (I've read the paper but am not WBH).

The H15 paper in an edited volume has 1 citation per Google Scholar, but extends work on terrestrial planets' evolution in other recent papers accumulating 200+ citations. Google finds it available on the Mantleplumes.org website, and possibly several other locations apart from the GSA book's own page.IChiloe (talk) 18:24, 25 November 2016 (UTC)

I have removed this entire section. It is a fringe idea not supported in the scientific literature and not taken seriously (if it is even known about) by the scientific community-see all presented work on martian volcanism at the recent Lunar and Planetary Science Conference. The sole source (several paragraphs from Hamilton's 2015 book chapter "Terrestrial planets fractionated synchronously with accretion, but Earth progressed through subsequent internally dynamic stages whereas Venus and Mars have been inert for more than 4 billion years") argues that ALL martian volcanoes are impact-generated, so it would belong on Volcanology of Mars if it wasn't such a fringe idea. Hamilton argues that Alba, Arsia, Pavonis, and Ascraeus are all formed from bolides, based on no evidence other than his personal objection to mantle plumes on Earth. Hamilton continues to argue that other features identified as lava flows in the southern highlands are in fact "mud volcanoes", also with no evidence other than his personal opinion. The only source (Hamilton 2015) is cited by two articles (as per Google Scholar), neither of which is related to martian volcanism. — Preceding unsigned comment added by Ammorgan2 (talk • contribs) 17:22, 10 April 2017 (UTC)

Olympus Mons is not high because of the absence of plate tectonics

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)

Nice spot. DanHobley (talk) 09:29, 4 June 2020 (UTC)

Olympus Mons is not the largest volcano in the Solar System

User:Venezia Friulano this is mostly directed at you, since you recently erased the part of the intro that clarified this point.

Olympus Mons is the tallest known volcano in the solar system, and it'll probably keep that title. However, if "largest" is judged by either area or volume, it is not the largest nor even close to the largest known volcano in the solar system. The largest by either of those metrics is Alba Mons, which is 2700 km wide at its widest, compared to Olympus at about 600 km. Pele and Tvashtar on Io, Leviathan on Triton, and Theia on Venus are all also distinctly larger than Olympus. This is not an exhaustive list, but you should have no trouble verifying that all of these are significantly larger than Olympus Mons.

The older version of the intro explained this in detail. I would like to revert to that version. Destrucules (talk) 03:30, 23 September 2021 (UTC)

Hi! I have made the changes because both NASA and ESA (European Space Agency) establish that Olympus Mons "is the largest volcano in the solar system", at least discovered so far. I think they are two sources reliable enough, or at least particularly better than theoretical estimates from still fairly unknown places.

"[...] the planet is known to host numerous massive and imposing volcanic structures, including the famous Olympus Mons – the largest volcano ever discovered in the Solar System."

"The largest of the volcanoes in the Tharsis Montes region, as well as all known volcanoes in the solar system, is Olympus Mons."

Also, I think the previous version spent too much on size comparisons, to be honest. User:Venezia Friulano (talk) 03:30, 23 September 2021 (UTC)

We don't include duff info just because a semi-popular source says something; WP:RS doesn't work that way round William M. Connolley (talk) 15:31, 24 September 2021 (UTC)

Also, I don't think the extensive comparisons belong in the lede but should probably be introduced in some separate subsection William M. Connolley (talk) 15:36, 24 September 2021 (UTC)

There are many reliable sources that claim that Olympus Mons is the largest volcano in the Solar System. I don't see any problem:

User:Venezia Friulano (talk) 18:47, 25 September 2021 (UTC)

What you're missing is the ambiguity in the word "largest"; it isn't useful to anyone to replicate that ambiguity William M. Connolley (talk) 21:27, 25 September 2021 (UTC)

I don't see it as ambiguous particularly considering that many reliable sources use that term, and there is scientific consensus that Olympus Mons is the largest volcano in the solar system.

By largest, in mega structures such as mountains or volcanoes, it is always understood by volume. Mauna Loa is officially the largest volcano in the world (not counting the hypothetical volcano Tamu Massif) because it has the most volume of all. Volume is the measure and the reference in scientific terms for calculating the size of a geological structure. User:Venezia Friulano (talk) 12:16, 26 September 2021 (UTC)

It is telling that you are using articles and not scientific sources. That Olympus Mons is the "largest" volcano in the solar system is a popular misconception, not the scientific consensus. In scientific publications, Olympus Mons is referred to as the tallest mountain on Mars and as one of the largest, but it is not referred to as the largest volcano on Mars, let alone in the greater solar system. Here are some examples:

https://doi.org/10.1016/j.epsl.2012.12.020

https://doi.org/10.1038/309432a0

https://doi.org/10.1016/j.icarus.2017.11.003

It is very easy to verify that in terms of area, Olympus Mons is not close to being the largest volcano in the solar system. That is already a degree of ambiguity that needs to be addressed. Volume estimates are much harder to come by for a variety of reasons, but Alba Mons appears to be more voluminous than Olympus.

As much as we might wish otherwise, misconceptions about science have existed for centuries and will continue to exist long into the future. Even scientists are not always immune from repeating popular misconceptions. In these cases, it is not sufficient to trust short articles aimed at inspiring the public. It is necessary to find publications from scientists working closely and directly with the relevant material. In this case it is very clear that these publications contradict what is expressed in those popular articles. Destrucules (talk) 19:07, 3 October 2021 (UTC)

Well, if there are conflicting sources, equally(?) reliable, we'll need to reflect exactly that in the article. --Zac67 (talk) 19:22, 3 October 2021 (UTC)

Destrucules, I understand what you mean in your last paragraph, but those "popular" articles are actually articles that are the result of calculations made by NASA, ESA and astronomical studies in Universities. Your first source calls it "Tallest shield volcano on Mars", your second source is from 1984, too old to take into account in such a matter... and the third source mentions it as "tallest volcano in the Solar System". Your sources dont contradict anything of the previous sources. In addition, your sources are only abstracts, they dont differ in practice at all in format.

Probably the most legitimate sources of scientific information on this particular matter textually affirm that it is the largest and tallest volcano in the Solar System. Using other sources where they say another smaller adjective doesnt expressly contradict anything. User:Venezia Friulano (talk) 10:28, 5 October 2021 (UTC)

In addition, there are also scientific sources where the same thing is stated literally: User:Venezia Friulano (talk) 10:42, 5 October 2021 (UTC)

References

Distance of horizon

The article currently says "Similarly, an observer near the summit would be unaware of standing on a very high mountain, as the slope of the volcano would extend far beyond the horizon, a mere 3 kilometers away." 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)