Mount Sharp or Aeolis Mons?

What should the towering peak inside Gale crater be called? Two names are being used — one is derived from longstanding classical mythology, while the other honors a beloved planetary geologist.

Oblique view of Gale crater on Mars
NASA / JPL / ESA / DLR / FU Berlin / MSSS
In a few weeks, after NASA's Curiosity rover — a.k.a. Mars Science Laboratory — has spent some time scratching and sniffing around its immediate environs, the rover will make tracks (so to speak) for its main objective: a towering peak that rises 3 miles (5 km) from the floor of Gale crater.

The huge massif was unknown to astronomers prior to spacecraft reconnaissance of Mars. In fact, early in the planning stages for Curiosity's journey, mission scientists referred to it simply as "The Mound." That seemed somewhat undignified for such an imposing and (for the rover) all-important feature, so they undertook an effort to name the mountain.

But the unintended result was two names: Aeolis Mons and Mount Sharp. Here's how this confusing outcome came about.

Back in 1973 the International Astronomical Union assigned the task of naming solar-system objects to a new committee, the Working Group for Planetary System Nomenclature (WGPSN). For nearly four decades WGSPN has seamlessly coordinated naming rights for dozens of solar-system bodies. Its members decided, for example, to name mountains on Mercury using the words for "hot" in various languages and craters on the moons of Uranus after characters in Shakespeare's plays.

In the case of Mars, large craters can be named after deceased scientists (along with writers and others) who have contributed to Martian knowledge and lore. But large mountains can not — and therein lies the crux of the issue regarding the object of Curiosity's forthcoming attention inside Gale crater.

Tall peak inside Gale crater
Inside Gale crater lies an enigmatic stack of sediments some 3 miles (5 km) high — taller than the crater's north rim, as this topographic map shows. But there's confusion among scientists as to what it should be called. A yellow cross shows the landing site for NASA's Curiosity rover inside the elliptical target zone. Click on the image for a larger view.
NASA / MOLA team
You've probably heard "Mount Sharp" used a lot these past two weeks. It's the moniker favored by the mission scientists themselves. Many of them had close ties to Robert P. Sharp (1911–2004), a consummate field geologist and a key figure in formative years of planetary exploration. Sharp taught geology at Caltech from 1948 until well past retirement, influencing and guiding many current planetary scientists along the way.


"We received a request from the MSL team to name the mountain in Gale and a large crater adjacent to Gale," explains Brad Smith, who chairs the WGSPN's Mars Task Group. "They had suggested Sharp as a name for both." But mountain men were off limits according to IAU rules, and there's already a lunar crater named Sharp. "I suggested instead that the crater could be named Robert Sharp," Smith says, which was approved. About 95 miles (152 km), it lies just to Gale's west-northwest — Curiosity flew right over the crater as it dropped through the Martian sky last week.

The big mound does have a name that passes IAU muster: Aeolis Mons. Mons is Latin for mountain, and Aeolis is associated with a region of Mars identified by telescopic observers as far back as the 1870s. In Greek mythology, Aeolis was a floating island where winds were kept in a cave inside a mountain. The name has been formally associated with this region of Mars since 1958, when it was recognized as such by the International Astronomical Union.

According to the IAU's naming conventions, mountains of this large size must likewise carry mythological names. So in May, the Mars task group assigned it the name Aeolis Mons. It's part of a family of features in this region, such as Aeolis Planum (a plateau), Aeolis Dorsum (a ridge), and so forth. The flat expanse of crater floor that Curiosity landed on is named Aeolis Palus.

"I think it's an anachronistic system, and that the IAU should open up to special purposes," counters John Grotzinger, MSL's project scientist and a Caltech geologist who knew Sharp as well as anyone. "The people who spend so much time studying it should have a say in the matter." Grotzinger insists that he and his team will use Aeolis Mons once they publish the mission's results, but he sees no harm in using "Mount Sharp" when describing it informally to the news media and the public.

(Science writer Daniel Fischer has alerted me to at least one journal article, published last month, in which the MSL science team hasn't held to that pledge and chose to use "Mount Sharp" throughout.)

NASA's public-affairs folks initially made a modest attempt to note that "Mount Sharp" is an informal name, though Aeolis Mons appears nowhere in the 61-page guide to Curiosity's landing that they assembled for reporters. During the week of press briefings after the landing, I heard the project's key scientists use "Mount Sharp" dozens of times — which isn't surprising, since they're the ones who suggested it in the first place.

This isn't the first time that mission personnel have trumped tradition. In February 2004, just weeks after it thumped onto the floor of Gusev crater, the rover Spirit spied a clutch of distant mounds that NASA officials decided to name, individually and collectively, for the seven astronauts killed aboard the Space Shuttle Columbia one year earlier. Today, they're universally called the Columbia Hills, even in scientific literature, because, as Smith points out, "The IAU never received a request from the scientific community to provide a formal name for them."

Robert Sharp crater
This topographic map shows the proximity of the recently named crater Robert Sharp to Gale crater.
NASA / MOLA team
I must admit that my allegiance is torn in the Gale case. Sky & Telescope has always made a point of adhering very closely to IAU conventions, and so have I. On the other hand, I took classes from Bob Sharp during my undergrad days at Caltech. If I hadn't, I probably wouldn't be typing these words now.

So we put the question to our e-newsletter subscribers. We set up a poll, asking readers to choose which name they liked best after reading the rationale for both names. The response, from more than 2,700 of you, gave tradition the edge: 57% voted for Aeolis Mons, compared to 43% for Mount Sharp. While our poll wasn't scientifically rigorous, it suggests there's ample room for both points of view. Some of the comments were fascinating; here's a sampling:

  • Bill Wright: "What's the IAU's hangup with naming a Martian mountain after an ancient Greek myth? How Euro-centric can it get? Greek mythology is not Earth mythology."
  • Jim Hamm: "I kind of like the Latin names, but rather than Aeolis Mons, how about calling it Curiositas Mons?"
  • Guilio Pecora: "For any modern translator, Mons is the name of a nice, little Belgian city, whereas Mount Sharp is a name that can be understood fairly easily at any latitude on Earth."
  • Anthony Barriero: "If you want to change the convention, join the International Astronomical Union and start a petition."
  • Andrea Mazzoleni: "The use of the Latin doesn't disturb me. It is a 'dead' language neutral even to me in Italy."

I'm guessing that future articles about Curiosity's exploits — both here and in Sky & Telescope itself — will use wording to describe The Mound something like: "… Aeolis Mons, but known widely as Mount Sharp …" Maybe I should start compiling lots of generic synonyms so I don't have to use either one.

What's your take? Let me know your thoughts in the comments below.

By the way, Gale crater is named for Walter F. Gale (1865–1945), an Australian banker by day but a dedicated amateur astronomer by night who built his own telescopes and discovered a number of comets.

24 thoughts on “Mount Sharp or Aeolis Mons?

  1. Dieter Kreuer

    Aeolis Mons has an official name given to it by those who have the authority. I find it counterproductive and confusing that JPL is calling it by another name now.
    If I should discover an asteroid, I may make a proposal for a name, but it will be named by the IAU as well, that’s the plain and simple rule. I understand the team’s motivation to honour Mr. Sharp by giving his name to a significant landmark, and this has been achieved by naming a crater. They might as well have called Curiosity the "Robert Sharp Memorial Base" or something like that (wasn’t it the habit to change names of probes ones they have reached their destination?), but they should accept the official name of Mons Aeolis now and use it *especially* when talking to the press to avoid public confusion.

  2. Justin SJustin

    In my opinion, NASA can call it anything they want to call it. The naming commitee should accept common usage and stick to naming otherwise unnamed objects and features. Let’s get real folks.

  3. Chris Jones

    I strongly agree with Dieter Kreuer’s well-written comment (and, by extension, disagree with Justin’s). I also find JPL’s reasoning specious, and calling the convention "outdated" is weak justification at best. It’s as if I say the name "Jet Propulsion Laboratory" is outdated, which it inarguably is, and, noticing that there is a planetary scientist named Chris Jones who works there, declare "Chris Jones Planetary Laboratory" is a much more appropriate name and I unilaterally declare that to be the name, and I will henceforth refer to it by that name. What do the Chris Jones Planetary Laboratory scientists think of that? By their own example, they must be fine with it.

  4. Todd

    Getting pretty tired of a bunch of pompous prats bestowing on themselves the rights to decide what something someone else discovers should be named.
    If they want to name something, then they can bloody well discover something besides a way to get their bureaucratic selves on a panel. Hell, why should everyone else have to dance to their tunes, use a dead language only used by scientists and clergy?
    Since when did the celestial bodies become their property and their exclusive right to name? And no, I don’t care about when they were told to by some other pompous group who decided they needed another pompous group to name things.


    Just the kinda self satisfied pomposity I mean too. Maybe he should try PAYING for all this stuff himself then.

  5. Mike W. Herberich

    Abolishing Latin names (in astronomy alone, let alone elsewhere!) would amount to losing 90% of all names, I estimate. Uhm … by the way: every SECOND word in English is either directly Latin or immediately derived from it: in my own comments first two lines I count 7 of them. In the last sentence, 6! So, who’s gonna replace all these words by ones of English or German or other origin? When? How? Then: a committee having the right of naming should be (and has been, I guess) put in power by democratic rule, like anything else in the democratic West. And: for millions of places and things people involved with it tend to find their own, sometimes shorter names. How do you want to counter that? Prohibit it? By what law? A democratic one? Any questions?

  6. Dieter Kreuer

    The IAU is not just any "bunch of pompous prats" but (please check Wikipedia) "the internationally recognized authority for assigning designations to celestial bodies […] and any surface features on them" with 70 member states, among them the USA, of course, and most countries active in astronomical research. What would be the alternative? Anybody calling anything as they like? Even if you assign the right of naming to the discoverer, this may result in stupid names ("Lady-Gaga-Crater"), double-assignments, or political issues ("Mount Stalin"). The best solution is to have an international body deciding on the final names according to widely accepted rules (and accepting proposals that match the rules). If the rules (such as strict use of Latin, the particular classes of names for certain objects) are the best imaginable ones is certainly open to discussion, but this brings us back to the suggestion to start a petition. The IAU is a democratically organized body, and democracy has widely been accepted as the best way to handle differing interests, or hasn’t it?

  7. Jim Horn

    The above comments ignore the fact that the lander team has been dealing with this landing site and then un-named mountain for years, finally naming it in March of this year while proposing that name to the IAU. The latter decided otherwise in May, after JPL had used the proposed name in many documents. As such, JPL’s comments are understandable and reasonable.

    Of course, the IAU is the recognized authority so their decision stands. Then again, I recall a large solar system object that they recognized as a planet for decades but then changed their mind…

    Similarly, when the USSR got the first image of the far side of the moon, it named several craters that the IAU accepted later. So there’s plenty of precedent for acceptance of names given by others. The lack of that in this case is a shame and could have been expected to cause the problems that it has.

  8. Jim Horn

    Technically, the peak is "Aeolis Mons, also called Mount Sharp". My name is James but I’m also called Jim. A simple distinction. I live near Portland, also called Stumptown. Many examples come to mind.

  9. Mike W. Herberich

    Here’s another one: "… Her name was Magil and she called herself Lil but everyone knew her as Nancy. …". Sincerely, me, myself and I.

  10. Tim Cole

    The IAU has jurisdiction over names for a good reason. "Mount Sharp" is reasonable name, but what about other great names in planetary sciences? I think we should stick to Aeolis Mons.
    Having said that, other posters have pointed out we can use "call names" for informal purposes. It works for show dogs!

  11. Barry Scholles

    Ever since my alma mater the University of Akron decided to change the name of an outdoor athletic area on campus from Jackson Field to Infocision Stadium I have been averse to giving new names to things where there once was a person’s name attached to it. I vote in favor of Mt. Sharp in memory of a real person who contributed something, apparently a lot, to human geological knowledge not some meaningless Greek name.

  12. Ed-MarshallEd Marshall

    When I saw the poll, I decide to check it out because I didn’t even realize there was an official name. I think Aeolis is a wonderous name and seems fitting that a rover named Curiosity is heading up there. Also, I think it’s wonderful to celebrate people like Robert Sharp and to acknowledge their contributions to so many people that represents the soul of Curiosity herself. JPL has always given unofficial names to the places it has visited, and I always just figured that was part of the game. So maybe this is a size issue, but Endeavour Crater is on the same scale, and that didn’t seem to be a problem. I’m okay with the unofficial names, because just wait until Curiosity starts moving! Hills, valleys, and canyons will all pick up names. It’s just another branch of NASA-ese that we’ve all gotten use to and most of us learn to speak. I just lost my wife last year to cancer, and you can bet that I’ve been spying out some hill, canyon, or crater to call "Melanie".

  13. David Zacker

    The "conservative", strictly Latin "Curiosus Mons" vs. the "liberal", non-traditional "Mount Sharp". In this election year, you could put it to a vote!

  14. Mark Olson

    The IAU (like many other scientific bodies in charge of naming) could be the type specimen for "a foolish consistency". When they focus on their job of facilitating communication, they’re golden. When they get hung up on making pretty patterns, they need to be slapped down.

    A great example is when IUPAC’s naming committee decided to *rename* a number of transuranic elements that had been named by their discoverers and whose names had been being used in the literature for years. The scientific community quite rightly ignored them and, ultimately, they backed down.

  15. Richard Carroll

    From THROUGH THE LOOKING GLASS by Lewis Carroll, Chapter 8.

    The name of the song is called "HADDOCKS’ EYES."’

    ‘Oh, that’s the name of the song, is it?’ Alice said, trying to feel interested.

    ‘No, you don’t understand,’ the Knight said, looking a little vexed. ‘That’s what the name is CALLED. The name really IS "THE AGED AGED MAN."’

    ‘Then I ought to have said "That’s what the SONG is called"?’ Alice corrected herself.

    ‘No, you oughtn’t: that’s quite another thing! The SONG is called "WAYS AND MEANS": but that’s only what it’s CALLED, you know!’

    ‘Well, what IS the song, then?’ said Alice, who was by this time completely bewildered.

    ‘I was coming to that,’ the Knight said. ‘The song really IS "A-SITTING ON A GATE": and the tune’s my own invention.’

  16. Jim

    This really is a silly argument. I can understand that convention would dictate a Latin name, but modern researchers who are doing the hard graft want to name the peak after a distinguished former colleague…we have an impasse..

    How about Acutus Mons. Acutus is Latin for keen, acute, pointed, cutting, spiky and finally SHARP, thus it can be seen as in honour of Bob Sharp, but it is also in keeping with the latinised naming convention??

    I suppose one could also question whether this is truly as mountain as it is the central peak of an impact crater, mountains are either formed by crustal plate movements (fold) or by volcanism, this is neither so there is an argument for breaking with convention and simply calling is SHARP

  17. Alison

    I don’t much care what they call the mountain. I do hope though, if there isn’t one already, that they’ll find a Martian crater to name "Bradbury".

  18. Mike W. Herberich

    I find this an excellent suggestion, Alison; I’m an ardent fan of his and thus support your hope! He deserves more than merely one crater, I think. Ray rules! (By the way, he died just lately … was it the 4th of July?)

  19. Mike W. Herberich

    Our prayers were answered, Alison: I just learned they named Curiosity’s landing site "Bradbury landing". That is very appropriate, I think. Having read not only Bradbury’s "Marsian Chronicles" but rather most of what he wrote and being a fan for the subtlety of his stories, their "non-sci-fi-ness", if you will, their psychological grounds and implications rather than a pure technicalized kind of Sci-Fi, I believe it is well deserved to have his name up there somewhere. Somewhere near one of the main topics of his tales and fantasies.

  20. Eugene Dees

    All this naming and renaming just makes it easier to change names when it becomes politrically expedient. Let’s call the three craters "Larry", "Curly" and "Moe" or, like back when there was a similar debate about what name to choose for an Apollo Command Module … and one of the astronauts expressed his exasperiation by suggesting the name "George".
