# The Antikythera Mechanism > Eighty-two corroded bronze fragments recovered from a Roman-period shipwreck off Antikythera in 1901 are the remains of a geared astronomical calculator… Source: https://mysteriesdept.com/mysteries/antikythera-mechanism Publisher: Mysteries Department Licence: CC BY 4.0 (credit Mysteries Department and link the page) Updated: 2026-10-27T17:47:05+00:00 --- **MYS** 0D3FQ0XA446F·Mystery · object # The Antikythera Mechanism **0** [Follow][Ask a question](https://mysteriesdept.com/questions/key-questions?mystery=antikythera-mechanism) The Antikythera Mechanism ![Main w:en:Antikythera mechanism fragment (fragment A).](https://mysteriesdept.com/media/folio/antikythera-mechanism-lead) Marsyas · CC BY 2.5 Holder National Archaeological Museum, Athens, inventory X 15087⁠[[2]] Found Sponge divers' salvage of the Antikythera wreck, 1900 to 1901; fragments recognised in May 1902⁠[[1]] Fragments 82 (A to G and 1 to 75), as inventoried in 2005⁠[[1]] Gears At least 30 surviving bronze gears⁠[[15]] Made Second or first century BC; eclipse-predictor epoch 205 BC⁠[[12]] Main study Freeth et al. 2006 (Nature), 2008 (Nature), 2021 (Scientific Reports)⁠[[4]] Open data CT volume of Fragment A (Harvard Dataverse) and PTM images (NYU)⁠[[15]] Status Partly explained Questions 0 of 5 answered People [**Alexander Jones** Historian of astronomy; inscriptions and epoch dates](https://mysteriesdept.com/mysteries/antikythera-mechanism/people/FIG0D3FQ2C631E9/alexander-jones)[**Derek de Solla Price** First full study, 1974](https://mysteriesdept.com/mysteries/antikythera-mechanism/people/FIG0D3FQ1WJ048G/derek-de-solla-price)[**Paul Iversen** Epigrapher; the Corinthian calendar argument](https://mysteriesdept.com/mysteries/antikythera-mechanism/people/FIG0D3FQ2M07B4T/paul-iversen)[**Valerios Stais** Credited with recognising the mechanism in 1902](https://mysteriesdept.com/mysteries/antikythera-mechanism/people/FIG0D3FQ1MR6P5F/valerios-stais)[**Tony Freeth** Lead author of the 2006, 2008 and 2021 reconstructions](https://mysteriesdept.com/mysteries/antikythera-mechanism/people/FIG0D3FQ24C6GTP/tony-freeth) Catalog key**MYS** 0D3FQ0XA446F In 1900 sponge divers found a shipwreck off the island of Antikythera, between Crete and the Peloponnese, and in 1900 and 1901 raised bronze and marble statues, glass, pottery and coins for the Greek state. In May 1902 Valerios Stais, a former minister, was credited with noticing that a lump of corroded bronze among the finds carried gear wheels and inscriptions, although the fragments had probably been noticed earlier⁠[[1]]. Four fragments were described in 1903; later recognitions and splits brought the inventory to 82 pieces, lettered A to G for the larger ones and numbered 1 to 75 for the rest, all in the National Archaeological Museum in Athens⁠[[1]]⁠[[2]]. Derek de Solla Price's 1974 monograph established from radiographs that the device was a geared calendrical and astronomical calculator and reconstructed its main train⁠[[3]]. The decisive step came in 2005, when the Antikythera Mechanism Research Project, with X-Tek Systems and Hewlett-Packard, made high-resolution X-ray computed tomography scans and reflectance images of every fragment in the museum⁠[[4]]⁠[[2]]. The 2006 paper in Nature read the gear train and inscriptions in the CT data and showed a pin-and-slot device that modelled the moon's varying speed, the 19-year Metonic cycle, the 223-month Saros eclipse cycle and a lower back dial for eclipse prediction⁠[[4]]. The 2008 paper read the month names of the Metonic dial, which belong to the Corinthian family of calendars, and found a dial for the four-year cycle of the Panhellenic games⁠[[5]]. A 2021 paper proposed a full reconstruction of the lost front display with the five planets⁠[[6]]. The open questions are narrower than they were but real. The front calendar ring, long taken to have 365 divisions for the Egyptian civil year, was argued in 2020 to have 354, a lunar year, from the spacing of surviving holes; two independent 2024 analyses supported a count near 354, and a 2025 reconstruction insisted on 365⁠[[7]]⁠[[8]]⁠[[9]]⁠[[10]]. A 2025 simulation argued that, with the tooth errors measured in the fragments, the gear train would have jammed within months, so either it never ran or the measurements overstate the errors⁠[[11]]. The date of manufacture is bracketed between an eclipse-table epoch of 205 BC and the wreck of about the mid first century BC, and the maker's city is argued between Rhodes, Syracuse and the Corinthian north-west⁠[[12]]⁠[[13]]⁠[[14]]⁠[[5]]. Of the 5 questions on this site, 0 are answered. The most likely answer to “Did the mechanism function as built?”, not yet confirmed: the mechanism ran as designed, with tooth errors smaller than those measured in the corroded fragments. ### Key questionsset by the editors [**Did the mechanism function as built?** ](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ59Y5GC6/did-the-mechanism-function-as-built)Most likely: the mechanism ran as designed, with tooth errors smaller than those measured in the corroded fragments [**How many divisions did the front calendar ring have?** ](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ5244P7K/how-many-divisions-did-the-front-calendar-ring-have)Most likely: the ring had 354 holes, a lunar year, so the Egyptian calendar ring sat over a lunar-year scale [**When was the mechanism made?** ](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ5HR1FYH/when-was-the-mechanism-made)Most likely: the astronomical scheme was fixed to an epoch of 205 BC and the device was made then or soon after [All 5 questions ](https://mysteriesdept.com/questions/key-questions?mystery=antikythera-mechanism) ## The object The fragments are bronze, heavily corroded to copper salts, with the gears, plates and inscribed surfaces preserved as mineralised shapes inside the mass. Fragment A, the largest, holds the main train with 27 gears; Fragment B the Metonic spiral; Fragment C the front dial with its zodiac and calendar rings; Fragment D a single gear; E, F and G and the small pieces carry further gears and text⁠[[4]]⁠[[1]]. The inscriptions, in a Greek script dated by letter forms to roughly the late third to the mid first century BC, include a front parapegma of star risings and settings, a back-cover "user's guide" describing the dials and the planetary display, and the month names and eclipse glyphs on the back dials⁠[[1]]⁠[[4]]. [![The Antikythera Mechanism fragments (X 15087)](https://mysteriesdept.com/files/4fd1e8747276857406d5700abc2e63db59f81387adfaa8c6892265e83e219d7c.jpg)](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts/ART0D3FQHGJ7DZP/the-antikythera-mechanism-fragments-x-15087) The Antikythera Mechanism fragments (X 15087)Therese Clutario, 1900. CC BY 2.0[Artifact ](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts/ART0D3FQHGJ7DZP/the-antikythera-mechanism-fragments-x-15087) The primary data are the 2005 X-ray CT scans and polynomial texture maps. The PTM images of all known surfaces are published by the Institute for the Study of the Ancient World at NYU under the Open Database Licence⁠[[2]]. A reprocessed CT volume of Fragment A, with missing projections corrected, is on the Harvard Dataverse with the 2018 paper that produced it⁠[[15]]. **Map of the region** [Open the full map](https://mysteriesdept.com/mysteries/antikythera-mechanism/map) [+][−] 1 **Antikythera shipwreck** Shipwreck site Within 1 km 2 **Antikythera** Island A region 3 **National Archaeological Museum, Athens** Museum Within 100 m MappedWithin 1 kmA regionNatural Earth ### Timeline **Timeline** Squeezed where little happened. Each mark is a published claim, by how it stands:AcceptedMost likelyStill possibleDisputedRuled out ## What is known The gearing is understood in its main lines. An input turned a crown wheel that drove the main train; the front dial showed the sun and moon in the zodiac and the moon's phase on a rotating ball; a pin-and-slot coupling on epicyclic gears varied the moon's speed according to Hipparchus's lunar theory, the earliest known mechanical model of an astronomical anomaly⁠[[4]]. The back had two spiral dials: an upper one of 235 months for the Metonic cycle, with a subsidiary games dial and a Callippic dial, and a lower one of 223 months for the Saros cycle, with glyphs predicting lunar and solar eclipses and their times, and a subsidiary exeligmos dial⁠[[4]]⁠[[5]]. The Metonic month names belong to the Corinthian family of calendars, which pointed the 2008 authors toward Corinth's colonies and Iversen's 2017 study toward Epirus⁠[[5]]⁠[[14]]. The back-cover inscription names the planets and their displays, which the 2021 reconstruction used to propose a front display of all five with their synodic cycles, a reconstruction that is mechanically plausible but not attested by surviving gears⁠[[6]]. [![The inscriptions on the fragments (parapegma, back-cover guide, dial legends)](https://mysteriesdept.com/files/v/930e76a78bfe08411404303cae4f7cf4d4baf996252166881487ec4557c51575/w800)](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts/ART0D3FQKYP5TZQ/the-inscriptions-on-the-fragments-parapegma-back-cover-guide) The inscriptions on the fragments (parapegma, back-cover guide, dial legends)Freeth, T., Higgon, D., Dacanalis, A. et al., 2005. CC BY 4.0[Artifact ](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts/ART0D3FQKYP5TZQ/the-inscriptions-on-the-fragments-parapegma-back-cover-guide) On dating, Carman and Evans showed in 2014 that the eclipse table's starting point is best explained by a full-moon epoch in 205 BC, which puts the astronomical scheme earlier than the 150 to 100 BC range assumed in 2006; Jones's 2020 study confirms the eclipse-sequence dating, reaffirms the calendrical epoch and argues that the design decisions could still have been made by a maker working as late as the shipwreck⁠[[12]]⁠[[13]]. The wreck itself is placed in the first century BC by its cargo⁠[[1]]. ## What has been tested The calendar ring. The front dial's outer ring carried the 12 Egyptian months and could be rotated to compensate for the Egyptian year's drift against the seasons; it was fixed by pins in a ring of holes beneath. The 2006 and later reconstructions assumed 365 holes. In 2020 Budiselic, Thoeni, Dubno and Ramsey measured the 81 surviving holes in the CT data and, from their spacing, estimated a full count near 354, a lunar year⁠[[7]]. In 2024 Woan and Bayley applied Bayesian techniques from gravitational-wave astronomy to the same coordinates and found 354 or 355 holes, with 360 strongly disfavoured and 365 not plausible under their model⁠[[8]]. Dickens and Malin, re-analysing the same data with least squares and criticising the 2020 statistics, found 352.3 plus or minus 1.5 and put the chance of 365 below one in ten thousand⁠[[9]]. Specialists objected that the mechanism already had a lunar calendar on the Metonic dial, which would make a second, cruder one redundant⁠[[16]]. In 2025 Voulgaris, Mouratidis and Vossinakis published a reconstruction of the front dial that keeps 365 holes and argues that any other count would make the Egyptian ring malfunction⁠[[10]]. The dispute turns on the statistics of 81 hole positions in corroded metal and has not been resolved. [![Fragment C (front dial with zodiac and calendar rings)](https://mysteriesdept.com/files/v/d81b1d553c6581f95547d57e8e4bd6d3bc283cab1f5474ed71fc66c12b0908e6/w800)](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts/ART0D3FQJFT7ZJD/fragment-c-front-dial-with-zodiac-and-calendar-rings) Fragment C (front dial with zodiac and calendar rings)Logg Tandy. CC BY 4.0[Artifact ](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts/ART0D3FQJFT7ZJD/fragment-c-front-dial-with-zodiac-and-calendar-rings) Whether it worked. Szigety and Arenas built a computational model of the gear train with triangular teeth and the manufacturing errors measured by Edmunds in 2011, and found that the train jammed in 90 per cent of simulations, typically before the solar pointer completed a third of a turn; they conclude that either the device never functioned or the true errors were smaller than measured, and note that corrosion has deformed the gears the measurements rest on⁠[[11]]⁠[[17]]. The 2018 reprocessing of the Fragment A scan tested and rejected an earlier suggestion that the fragment had moved during scanning⁠[[15]]. ## The readings On function, the consensus is a display calculator for astronomical and calendrical cycles, built to show rather than to compute anything new, and the live disagreements are about the planets on the front, the calendar ring and the mechanical tolerances⁠[[6]]⁠[[8]]⁠[[11]]. On origin, three candidates are argued. Rhodes, because the lunar theory is Hipparchus's and Cicero places a planetary device with Posidonius there⁠[[4]]. Syracuse or another Corinthian colony, because the calendar is Corinthian and Cicero describes Archimedes' planetarium taken from Syracuse⁠[[5]]. Epirus or north-west Greece, because the month names fit that branch of the Corinthian family best⁠[[14]]. On date, the eclipse epoch of 205 BC marks the astronomical scheme; the physical object may be later, with the shipwreck as the lower bound⁠[[12]]⁠[[13]]. ### Published claims **Published claims and their status** | Year | Who | Claimed | Status | Reason | |---|---|---|---|---| | 1959 | Derek de Solla Price⁠[18] | The fragments are the remains of a geared computer that showed the calendar and the movements of the sun and moon. | Accepted | X-ray tomography recovered the gear trains and the astronomical cycles they modelled⁠[4]. | | 1974 | Derek de Solla Price⁠[3] | The main train included a differential gear that subtracted the sun's motion from the moon's to show the lunar phase. | Ruled out | The CT data showed no differential: the gears Price read that way carry the pin-and-slot lunar anomaly device⁠[4]. | | 2006 | Tony Freeth and colleagues⁠[4] | A pin-and-slot coupling modelled the moon's varying speed, and spiral back dials showed the 19-year Metonic and 223-month Saros cycles with eclipse predictions. | Accepted | The reading rests on the CT scans of every fragment and has been confirmed by the full edition of the inscriptions⁠[1]. | | 2008 | Tony Freeth and colleagues⁠[5] | The Metonic dial's month names are Corinthian and a subsidiary dial showed the Panhellenic games, which points to a Corinthian colony such as Syracuse. | Still possible | The Corinthian calendar is accepted, but Iversen finds the month names fit north-west Greece better than Syracuse⁠[14]. | | 2012 | Tony Freeth and Alexander Jones⁠[19] | The back-cover inscription describes a front display of the stars, sun, moon and all five planets, driven by planetary gearing like the lunar device. | Most likely | The planets are named on the cover inscription, but no planetary gear survives, so the gearing is conjecture⁠[6]. | | 2013 | Michael Wright⁠[20] | The planets were shown on the front dial by compound gear trains. | Still possible | No planetary gearing survives, so rival trains for the planets cannot be tested against the parts⁠[6]. | | 2014 | Christián Carman and James Evans⁠[12] | The eclipse predictor starts from a full moon in 205 BC, earlier than the construction date assumed in 2006. | Accepted | Jones's 2020 study confirmed the eclipse-sequence epoch independently⁠[13]. | | 2017 | Paul Iversen⁠[14] | The month names fit the calendar of Epirus or north-west Greece best within the Corinthian family. | Still possible | It rests on comparison with incompletely known calendars and no inscription on the mechanism names a city⁠[1]. | | 2020 | Alexander Jones⁠[13] | The 205 BC epochs follow from calendar practice, so the object itself could have been made as late as the shipwreck. | Most likely | It fits the Hipparchan lunar theory in the gearing and the first-century BC wreck, but no physical evidence dates the making⁠[4]. | | 2020 | Chris Budiselic and colleagues⁠[7] | The spacing of the 81 surviving holes under the calendar ring implies about 354, a lunar year, not 365. | Most likely | Two independent re-analyses of the hole positions agree on a count near 354, though a 2025 reconstruction holds to 365⁠[8]⁠[10]. | | 2021 | Tony Freeth and colleagues⁠[6] | The lost front display can be reconstructed with gearing for all five planets that fits the inscriptions and surviving parts. | Still possible | The cycles come from the inscription, but the planetary gearing itself has no surviving parts to test against⁠[6]. | | 2024 | Graham Woan and Joseph Bayley⁠[8] | A Bayesian fit to the hole positions gives 354 or 355 holes, with 360 strongly disfavoured and 365 not plausible. | Most likely | It agrees with a separate least-squares analysis of the same data, but specialists object that a second lunar calendar would be redundant⁠[9]⁠[16]. | | 2024 | R. J. Dickens and Stuart Malin⁠[9] | Least squares on the hole positions give 352.3 plus or minus 1.5 holes, putting the chance of 365 below one in ten thousand. | Most likely | It agrees with the Bayesian analysis, though all three analyses share one set of 81 holes in corroded metal⁠[8]. | | 2025 | Aristeidis Voulgaris and colleagues⁠[10] | The front dial needs 365 holes for the Egyptian calendar ring to work, and any other count would make it malfunction. | Disputed | Three statistical analyses of the surviving holes disfavour 365, though none models corrosion and fracture fully⁠[8]⁠[9]. | | 2025 | Esteban Szigety and Gustavo Arenas⁠[11] | With the tooth errors measured in the fragments, the gear train would have jammed within a few months of use. | Still possible | The errors were measured on corroded gears and the authors call the result speculative⁠[17]. | ## What would settle it The calendar ring question needs either more of the ring, which would require new finds from the wreck, or an agreed statistical treatment of the 81 holes with the uncertainties of corrosion built in; the three 2024 analyses already share one dataset⁠[[7]]⁠[[9]]. The functioning question needs tooth measurements that account for corrosion, which the reprocessed CT data make possible⁠[[11]]⁠[[15]]. The origin question would be settled by a maker's name or a city in the unread parts of the inscriptions, or by a second mechanism; the inscriptions are now largely read and name neither⁠[[1]]. The wreck has been re-excavated since 2012 and further fragments are possible⁠[[1]]. ## Questions 0 of 5 questions are answered. **Key questions** [All 5](https://mysteriesdept.com/questions/key-questions?mystery=antikythera-mechanism) **0** [Did the mechanism function as built?](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ59Y5GC6/did-the-mechanism-function-as-built) 0 of 1 sub-questions answered·0 Most likely: the mechanism ran as designed, with tooth errors smaller than those measured in the corroded fragments **0** [How many divisions did the front calendar ring have?](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ5244P7K/how-many-divisions-did-the-front-calendar-ring-have) 0 of 0 sub-questions answered·0 Most likely: the ring had 354 holes, a lunar year, so the Egyptian calendar ring sat over a lunar-year scale **0** [When was the mechanism made?](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ5HR1FYH/when-was-the-mechanism-made) 0 of 1 sub-questions answered·0 Most likely: the astronomical scheme was fixed to an epoch of 205 BC and the device was made then or soon after ## Evidence 25 findings [How many divisions did the front calendar ring have?](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ5244P7K/how-many-divisions-did-the-front-calendar-ring-have)9 findings [The ring had 365 holes, one per day of the Egyptian civil year.](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQ6966WEZ/the-ring-had-365-holes-one-per-day-of-the-egyptian-civil)Most likely +[The ring carries Egyptian month names, which belong to a 365-day calendar, and the 2025 front-dial reconstruction holds that 365 holes are required for the Egyptian ring to function.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ6H01NGJ/the-ring-carries-egyptian-month-names-which-belong-to-a-365)Suggestive −[A Bayesian fit to the 81 hole positions finds 365 not plausible and 360 strongly disfavoured.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ6RT3GS3/a-bayesian-fit-to-the-81-hole-positions-finds-365-not)Supported −[A least-squares re-analysis puts the chance of 365 below one in ten thousand.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ70M3MA5/a-least-squares-re-analysis-puts-the-chance-of-365-below-one)Supported [The ring had 354 holes, a lunar year, so the Egyptian calendar ring sat over a lunar-year scale.](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQ78E1S2G/the-ring-had-354-holes-a-lunar-year-so-the-egyptian-calendar)Most likely +[The 2020 measurement and spacing analysis gives about 354.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ7G86FY8/the-2020-measurement-and-spacing-analysis-gives-about-354)Suggestive +[Independent Bayesian analysis gives 354 to 355.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ7R209F5/independent-bayesian-analysis-gives-354-to-355)Supported +[Independent least-squares analysis gives 352.3 plus or minus 1.5, within 350 to 355 at 95 per cent.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ7ZW77VT/independent-least-squares-analysis-gives-352-3-plus-or-minus)Supported −[Specialists object that the Metonic dial already gives a lunar calendar, making a second, cruder one redundant.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ87P7ZBN/specialists-object-that-the-metonic-dial-already-gives-a)Suggestive [The ring had some other count (for example 360 or a count near 352), reflecting a different scheme.](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQ8FG1A2H/the-ring-had-some-other-count-for-example-360-or-a-count)Disputed +[Dickens and Malin's best estimate is 352.3, below 354, though they judge 354 far more likely than 365.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ8QA1VDR/dickens-and-malins-best-estimate-is-352-3-below-354-though)Speculative −[360 is strongly disfavoured by the Bayesian fit.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ8Z40GDG/360-is-strongly-disfavoured-by-the-bayesian-fit)Supported [Did the mechanism function as built?](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ59Y5GC6/did-the-mechanism-function-as-built)5 findings [The mechanism ran as designed, with tooth errors smaller than those measured in the corroded fragments.](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQ9ER4XE4/the-mechanism-ran-as-designed-with-tooth-errors-smaller-than)Most likely +[The gearing is coherent and complete enough to be reconstructed as a working train, and the inscriptions describe it as showing the heavens.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ9PJ7JQG/the-gearing-is-coherent-and-complete-enough-to-be)Supported +[The simulation's authors note that corrosion has deformed the gears their error measurements rest on, so the measured errors may overstate the originals.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQ9YC6ZTF/the-simulations-authors-note-that-corrosion-has-deformed-the)Suggestive [The mechanism as made would have jammed or lost engagement within a few months of operation.](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQA6652VN/the-mechanism-as-made-would-have-jammed-or-lost-engagement)Still possible +[With Edmunds's measured errors the simulated train jammed in 90 per cent of runs, typically before the solar pointer completed a third of a turn.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQAE03H2D/with-edmundss-measured-errors-the-simulated-train-jammed-in)Suggestive −[The authors themselves describe the result as speculative and dependent on the measured errors.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQANT5GJA/the-authors-themselves-describe-the-result-as-speculative)Suggestive [The mechanism was a display or teaching piece turned occasionally by hand, so intermittent sticking did not…](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQAXM5HFH/the-mechanism-was-a-display-or-teaching-piece-turned)Still possible +[The device is a display calculator with extensive explanatory inscriptions.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQB5E0K6R/the-device-is-a-display-calculator-with-extensive)Suggestive [When was the mechanism made?](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ5HR1FYH/when-was-the-mechanism-made)4 findings [The astronomical scheme was fixed to an epoch of 205 BC and the device was made then or soon after.](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQBN24PMC/the-astronomical-scheme-was-fixed-to-an-epoch-of-205-bc-and)Most likely +[The Saros dial's eclipse sequence is best explained by a starting full moon in 205 BC.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQBWW0TF7/the-saros-dials-eclipse-sequence-is-best-explained-by-a)Supported +[Letter forms are dated to roughly the late third to mid first century BC, which admits but does not require 205 BC.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQC4P6B1P/letter-forms-are-dated-to-roughly-the-late-third-to-mid)Suggestive [The scheme uses a 205 BC epoch but the object was made later, in the second or first century BC, up to the…](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQCCG615X/the-scheme-uses-a-205-bc-epoch-but-the-object-was-made-later)Most likely +[Jones argues the design decisions behind both epochs could have been made as late as the shipwreck.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQCMA2CA4/jones-argues-the-design-decisions-behind-both-epochs-could)Supported +[The pin-and-slot device models Hipparchus's lunar anomaly, which places the design in or after his lifetime.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQCW404CT/the-pin-and-slot-device-models-hipparchuss-lunar-anomaly)Suggestive [Where, and by whom, was the mechanism made?](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ5SJ2E5J/where-and-by-whom-was-the-mechanism-made)5 findings [Made on Rhodes, in the tradition of Hipparchus and Posidonius.](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQDBR0316/made-on-rhodes-in-the-tradition-of-hipparchus-and-posidonius)Most likely +[The lunar anomaly device embodies Hipparchus's theory and Cicero places a planetary device with Posidonius on Rhodes.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQDKJ6G16/the-lunar-anomaly-device-embodies-hipparchuss-theory-and)Suggestive −[The month names are Corinthian, not Rhodian.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQDVC5A15/the-month-names-are-corinthian-not-rhodian)Supported [Made in Syracuse or another Corinthian colony, in the tradition of Archimedes.](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQE366N29/made-in-syracuse-or-another-corinthian-colony-in-the)Most likely +[The Metonic dial's month names belong to the Corinthian family and the 2008 authors suggested Corinth's colonies.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQEB02NXW/the-metonic-dials-month-names-belong-to-the-corinthian)Suggestive −[Iversen's comparison finds the names fit north-west Greece better than Syracuse.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQEJT2E1D/iversens-comparison-finds-the-names-fit-north-west-greece)Suggestive [Made for, or in, Epirus or north-west Greece, where the calendar fits best.](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQETM3Z0A/made-for-or-in-epirus-or-north-west-greece-where-the)Most likely +[Iversen's 2017 study argues the month names match the Epirote branch of the Corinthian family.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQF2E67MH/iversens-2017-study-argues-the-month-names-match-the-epirote)Suggestive [Did the front dial display the five planets, and how?](https://mysteriesdept.com/mysteries/antikythera-mechanism/questions/QST0D3FQ61C2VH1/did-the-front-dial-display-the-five-planets-and-how)2 findings [The front displayed all five planets with their synodic cycles, as reconstructed in 2021.](https://mysteriesdept.com/mysteries/antikythera-mechanism/answers/ANS0D3FQFJ200V8/the-front-displayed-all-five-planets-with-their-synodic)Most likely +[The back-cover inscription names the planets and the reconstruction fits the described cycles with plausible gear counts.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQFSW3J3H/the-back-cover-inscription-names-the-planets-and-the)Suggestive −[No planetary gears survive, so the reconstruction rests on inscriptions and inference.](https://mysteriesdept.com/mysteries/antikythera-mechanism/evidence/EVD0D3FQG1P60CW/no-planetary-gears-survive-so-the-reconstruction-rests-on)Supported ## Artifacts The films, photos, papers and objects this mystery rests on, each with its own key and its distance from the original. **Artifacts** [See all 16](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts) Photo1 step from object [The Antikythera Mechanism fragments (X 15087)](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts/ART0D3FQHGJ7DZP/the-antikythera-mechanism-fragments-x-15087) Therese Clutario · CC BY 2.0 Photo1 step from object [Fragment C (front dial with zodiac and calendar rings)](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts/ART0D3FQJFT7ZJD/fragment-c-front-dial-with-zodiac-and-calendar-rings) Logg Tandy · CC BY 4.0 Transcription2 steps from object [The inscriptions on the fragments (parapegma, back-cover guide, dial legends)](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts/ART0D3FQKYP5TZQ/the-inscriptions-on-the-fragments-parapegma-back-cover-guide) Alexander Jones, Mike Edmunds, Tony Freeth, Yanis Bitsakis and others (Inscriptions of the Antikythera Mechanism) · free to read (NYU Faculty Digital Archive) Scan1 step from object [Gamma-ray and X-ray radiographs of the fragments (Karakalos and Price)](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts/ART0D3FQMP43B4W/gamma-ray-and-x-ray-radiographs-of-the-fragments-karakalos) Charalambos Karakalos; published by Derek de Solla Price · publisher [See all 16 artifacts](https://mysteriesdept.com/mysteries/antikythera-mechanism/artifacts) ## See also [ **Nebra Sky Disc** A bronze disc inlaid with gold sun, moon and stars, dug up by looters in 1999. ](https://mysteriesdept.com/mysteries/nebra-sky-disc) [ **Amber Room** An amber-panelled room from the Catherine Palace, last seen at Königsberg in 1945. ](https://mysteriesdept.com/mysteries/amber-room) [ **Gallo-Roman dodecahedra** About 130 hollow bronze dodecahedra from Roman provinces, 2nd to 4th century AD. ](https://mysteriesdept.com/mysteries/roman-dodecahedra) [ **Phaistos Disc** A clay disc stamped with 241 signs in spirals, found at Phaistos, Crete, in 1908. ](https://mysteriesdept.com/mysteries/phaistos-disc) ## References 1. 1.[Jones, A. 2016. The Inscriptions of the Antikythera Mechanism. 2. Historical Background and General Observations. Almagest.](https://mysteriesdept.com/sources/SRC0D3FPXZJ76EP/the-inscriptions-of-the-antikythera-mechanism-2-historical)[doi](https://doi.org/10.1484/J.ALMAGEST.5.110733)cited 9 times here**SRC** 0D3FPXZJ76EP 1. 2.[Antikythera Mechanism Research Project 2019. Antikythera Mechanism PTMs (collection, Texts and Artifacts of Ancient Astronomy). NYU Faculty Digital Archive, Institute for the Study of the Ancient World.](https://mysteriesdept.com/sources/SRC0D3FPXFY6C4S/antikythera-mechanism-ptms-collection-texts-and-artifacts-of)cited 8 times here**SRC** 0D3FPXFY6C4S 1. 3.[Price, D. 1974. Gears from the Greeks: The Antikythera Mechanism, a Calendar Computer from ca. 80 B.C.. Transactions of the American Philosophical Society.](https://mysteriesdept.com/sources/SRC0D3FPXQR0MBB/gears-from-the-greeks-the-antikythera-mechanism-a-calendar)[doi](https://doi.org/10.70249/9780871693006)cited 5 times here**SRC** 0D3FPXQR0MBB 1. 4.[Freeth, T., Bitsakis, Y., Moussas, X. et al. 2006. Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism. Nature.](https://mysteriesdept.com/sources/SRC0D8MQY5J38KW/decoding-the-ancient-greek-astronomical-calculator-known-as)[doi](https://doi.org/10.1038/nature05357)cited 11 times here**SRC** 0D8MQY5J38KW 1. 5.[Freeth, T., Jones, A., Steele, J. et al. 2008. Calendars with Olympiad display and eclipse prediction on the Antikythera Mechanism. Nature.](https://mysteriesdept.com/sources/SRC0D3FPWRG12B3/calendars-with-olympiad-display-and-eclipse-prediction-on)[doi](https://doi.org/10.1038/nature07130)cited 6 times here**SRC** 0D3FPWRG12B3 1. 6.[Freeth, T., Higgon, D., Dacanalis, A. et al. 2021. A Model of the Cosmos in the ancient Greek Antikythera Mechanism. Scientific Reports.](https://mysteriesdept.com/sources/SRC0D8MQYDC4S7K/a-model-of-the-cosmos-in-the-ancient-greek-antikythera)[doi](https://doi.org/10.1038/s41598-021-84310-w)cited 7 times here**SRC** 0D8MQYDC4S7K 1. 7.[Budiselic, C., Thoeni, A., Dubno, M. et al. 2020. The Antikythera Mechanism: Evidence of a Lunar Calendar. Horological Journal (British Horological Institute).](https://mysteriesdept.com/sources/SRC0D3FPYYT2M16/the-antikythera-mechanism-evidence-of-a-lunar-calendar)cited 7 times here**SRC** 0D3FPYYT2M16 1. 8.[Woan, G., Bayley, J. 2024. An improved calendar ring hole-count for the Antikythera mechanism: A fresh analysis. Horological Journal.](https://mysteriesdept.com/sources/SRC0D3FPZ6M1YM8/an-improved-calendar-ring-hole-count-for-the-antikythera)cited 5 times here**SRC** 0D3FPZ6M1YM8 1. 9.[Dickens, R., Malin, S. 2024. How Many Days in an Egyptian Year? Evidence from the Antikythera Mechanism. Horological Journal, April 2024, 140–145.](https://mysteriesdept.com/sources/SRC0D3FPZEE2K1W/how-many-days-in-an-egyptian-year-evidence-from-the)cited 5 times here**SRC** 0D3FPZEE2K1W 1. 10.[Voulgaris, A., Mouratidis, C., Vossinakis, A. 2025. Reconstructing the Antikythera Mechanism's Central Front Dial Parts: Division and Placement of the Zodiac Dial Ring. Journal of Astronomical History and Heritage.](https://mysteriesdept.com/sources/SRC0D3FPZP80P76/reconstructing-the-antikythera-mechanisms-central-front-dial)[doi](https://doi.org/10.3724/sp.j.140-2807.2025.01.15)cited 3 times here**SRC** 0D3FPZP80P76 1. 11.[Szigety, E., Arenas, G. 2025. The Impact of Triangular-Toothed Gears on the Functionality of the Antikythera Mechanism. arXiv.](https://mysteriesdept.com/sources/SRC0D3FPZY24AA3/the-impact-of-triangular-toothed-gears-on-the-functionality)[doi](https://doi.org/10.2139/ssrn.5202300)cited 7 times here**SRC** 0D3FPZY24AA3 1. 12.[Carman, C., Evans, J. 2014. On the epoch of the Antikythera mechanism and its eclipse predictor. Archive for History of Exact Sciences.](https://mysteriesdept.com/sources/SRC0D3FPYF66JCC/on-the-epoch-of-the-antikythera-mechanism-and-its-eclipse)[doi](https://doi.org/10.1007/s00407-014-0145-5)cited 6 times here**SRC** 0D3FPYF66JCC 1. 13.[Jones, A. 2020. The Epoch Dates of the Antikythera Mechanism (With an Appendix on its Authenticity). ISAW Papers 17.](https://mysteriesdept.com/sources/SRC0D3FPY7C1DJK/the-epoch-dates-of-the-antikythera-mechanism-with-an)cited 5 times here**SRC** 0D3FPY7C1DJK 1. 14.[Iversen, P. 2017. The Calendar on the Antikythera Mechanism and the Corinthian Family of Calendars. Hesperia.](https://mysteriesdept.com/sources/SRC0D3FPYQ07QNB/the-calendar-on-the-antikythera-mechanism-and-the-corinthian)cited 6 times here**SRC** 0D3FPYQ07QNB 1. 15.[Pakzad, A., Iacoviello, F., Ramsey, A. et al. 2018. Improved X-ray computed tomography reconstruction of the largest fragment of the Antikythera Mechanism, an ancient Greek astronomical calculator. PLoS ONE.](https://mysteriesdept.com/sources/SRC0D3FPX84498P/improved-x-ray-computed-tomography-reconstruction-of-the)[doi](https://doi.org/10.1371/journal.pone.0207430)cited 3 times here**SRC** 0D3FPX84498P 1. 16.[Whiddington, R. 2024. A New Study Shakes Up Our Understanding of the World's First Analog Computer. Artnet News.](https://mysteriesdept.com/sources/SRC0D3FQ05W0F1F/a-new-study-shakes-up-our-understanding-of-the-worlds-first)cited 2 times here**SRC** 0D3FQ05W0F1F 1. 17.[Whiddington, R. 2025. Did the Antikythera Mechanism Actually Work? A New Study Says It May Have Jammed. Artnet News.](https://mysteriesdept.com/sources/SRC0D3FQ0DP4TCA/did-the-antikythera-mechanism-actually-work-a-new-study-says)cited 2 times here**SRC** 0D3FQ0DP4TCA 1. 18.[Price, D. 1959. An Ancient Greek Computer. Scientific American.](https://mysteriesdept.com/sources/SRC0D3FQ15425V9/an-ancient-greek-computer)[doi](https://doi.org/10.1038/scientificamerican0659-60)cited 1 time here**SRC** 0D3FQ15425V9 1. 19.[Freeth, T., Jones, A. 2012. The Cosmos in the Antikythera Mechanism. ISAW Papers 4.](https://mysteriesdept.com/sources/SRC0D3FQ1CY6NK6/the-cosmos-in-the-antikythera-mechanism)cited 1 time here**SRC** 0D3FQ1CY6NK6 1. 20.[Wright, M. 2013. The Antikythera Mechanism: Compound Gear-Trains for Planetary Indications. Almagest.](https://mysteriesdept.com/sources/SRC0D3FQ1MR1G8F/the-antikythera-mechanism-compound-gear-trains-for-planetary)[doi](https://doi.org/10.1484/J.ALMAGEST.1.103717)cited 1 time here**SRC** 0D3FQ1MR1G8F Last edited 27 Oct 2026