Talk:Olympus Mons

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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)

Contents 1 First ascent 2 Atmosphere of Mars and Olympus 3 Exosquad 4 Geographical coordinate link doesn't work 5 Tallest in Solar System? 6 In Fiction 7 Questioning the results 8 Verfication tag 9 How far can you see from Olympus Mons?

[edit] 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)

• 29 May 2053 — Trilobite (Talk) 06:53, 28 Feb 2005 (UTC)
• 9 July 2078 — same day Wikipedia reaches 5 million articles :) Worldtraveller 12:46, 3 Mar 2005 (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)
• 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)
• 19 October 2067 bob rulz 11:54, Jun 21, 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)

May 22, 2087 is my guess! The QBasicJedi 08:12, 22 June 2006 (UTC)

[edit] 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)

[edit] 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.

[edit] 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)

[edit] 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?

[edit] 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)

[edit] 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)

[edit] 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)

[edit] 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