Pythagoras (crater)

Pythagoras
	Pythagoras shadowed with its central peak seen near the terminator boundary
Coordinates	63°30′N 62°48′W / 63.5°N 62.8°W
Diameter	130 km
Depth	5.0 km
Colongitude	60° at sunrise
Formation	Eratosthenian
Eponym	Pythagoras

Lunar Orbiter 4 image
(four light spots are blemishes on original)

Pythagoras is a prominent impact crater located near the northwestern limb of the Moon. T. W. Webb described it as "the deepest walled plain" in this quadrant of the visible Moon.^[2] It lies just to the northwest of the somewhat larger Babbage. The crater has an oval appearance due to the oblique viewing angle. Only the western face of the interior can be viewed from the Earth, the other side being permanently out of sight.^[3]

On the lunar geologic timescale, Pythagoras is a crater of Eratosthenian age.^[1] The well-preserved rim of Pythagoras has a wide terrace system, and a slight rampart around the exterior. Although generally circular, the crater outline has a hexagonal form. The floor is flattened, but with an irregular, hilly surface. There is evidence of landslips around the periphery.^[4]^: 10 In the center is a sharp, mountainous rise with a double peak that ascends 1.5 kilometers above the crater floor. Anorthosite with a very low mafic abundance^[5] and the infrared spectrum of pure crystalline plagioclase has been identified in the central peaks.^[6]

This crater is named after Greek mathematician and philosopher Pythagoras of Samos (c. 570 – c. 495 BC). Its designation was formally adopted by the International Astronomical Union in 1935.^[7] The name was incorporated into lunar nomenclature by Italian astronomer Giovanni Riccioli in 1651.^[8]

Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Pythagoras.

Pythagoras^[4]^: 310	Latitude	Longitude	Diameter
B	66.1° N	73.0° W	17 km
D	64.5° N	72.0° W	30 km
G	67.8° N	75.3° W	16 km
H	67.1° N	73.3° W	18 km
K	67.3° N	75.4° W	12 km
L	67.3° N	77.6° W	12 km
M	67.5° N	81.1° W	10 km
N	66.6° N	78.1° W	14 km
P	65.3° N	75.2° W	10 km
S	67.7° N	64.7° W	8 km
T	62.5° N	51.4° W	6 km
W	63.1° N	48.9° W	4 km

References

1 2 Wilhelms, Don E.; McCauley, John F.; Trask, Newell J. (1987). The geologic history of the Moon. USGS Professional Paper 1348. Washington: U.S. Government Printing Office. doi:10.3133/pp1348. Table 12.2.
↑ Webb, Rev. T. W. (1962). Celestial Objects for Common Telescopes (6th revised ed.). Dover. pp. 130, 154–159. Reprint: ISBN 978-0-486-20917-3
↑ Wood, Chuck (October 9, 2007). "Copernicus on the Limb". Lunar Photo of the Day. Retrieved 2026-05-18.
1 2 Bussey, B.; Spudis, P. (2004). The Clementine Atlas of the Moon. New York: Cambridge University Press. ISBN 978-0-521-81528-4.
↑ Lemelin, Myriam; et al. (May 2015). "Lunar central peak mineralogy and iron content using the Kaguya Multiband Imager: Reassessment of the compositional structure of the lunar crust". JRG Planets. 120 (5): 869–887. doi:10.1002/2014JE004778.
↑ Donaldson Hanna, K. L.; et al. (July 2014). "Global assessment of pure crystalline plagioclase across the Moon and implications for the evolution of the primary crust". Journal of Geophysical Research: Planets. 119 (7): 1516–1545. Bibcode:2014JGRE..119.1516D. doi:10.1002/2013JE004476.
↑ "Pythagoras". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
↑ Whitaker, Ewen A. (1999). Mapping and Naming the Moon. Cambridge University Press. pp. 60, 214. ISBN 978-0-521-62248-6.

Sources

Moore, Patrick (2001). On the Moon. Sterling Publishing Co. ISBN 978-0-304-35469-6.
Price, Fred W. (1988). The Moon Observer's Handbook. Cambridge University Press. ISBN 978-0-521-33500-3.
Rükl, Antonín (1990). Atlas of the Moon. Kalmbach Books. ISBN 978-0-913135-17-4.
Wlasuk, Peter T. (2000). Observing the Moon. Springer. ISBN 978-1-85233-193-1.

[Wilhelms_et_al_1987-1] 1 2 Wilhelms, Don E.; McCauley, John F.; Trask, Newell J. (1987). The geologic history of the Moon. USGS Professional Paper 1348. Washington: U.S. Government Printing Office. doi:10.3133/pp1348. Table 12.2.

[Webb_1962-2] Webb, Rev. T. W. (1962). Celestial Objects for Common Telescopes (6th revised ed.). Dover. pp. 130, 154–159. Reprint: ISBN 978-0-486-20917-3

[Wood_2007-3] Wood, Chuck (October 9, 2007). "Copernicus on the Limb". Lunar Photo of the Day. Retrieved 2026-05-18.

[Bussey_Spudis_2004-4] 1 2 Bussey, B.; Spudis, P. (2004). The Clementine Atlas of the Moon. New York: Cambridge University Press. ISBN 978-0-521-81528-4.

[Lemelin_et_al_2015-5] Lemelin, Myriam; et al. (May 2015). "Lunar central peak mineralogy and iron content using the Kaguya Multiband Imager: Reassessment of the compositional structure of the lunar crust". JRG Planets. 120 (5): 869–887. doi:10.1002/2014JE004778.

[Donaldson_Hanna_et_al_2014-6] Donaldson Hanna, K. L.; et al. (July 2014). "Global assessment of pure crystalline plagioclase across the Moon and implications for the evolution of the primary crust". Journal of Geophysical Research: Planets. 119 (7): 1516–1545. Bibcode:2014JGRE..119.1516D. doi:10.1002/2013JE004476.

[GPN-7] "Pythagoras". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.

[Whitaker_1999-8] Whitaker, Ewen A. (1999). Mapping and Naming the Moon. Cambridge University Press. pp. 60, 214. ISBN 978-0-521-62248-6.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

Moon
Outline
Physical properties	Internal structure Topography Atmosphere Gravity field Hill sphere Magnetic field Sodium tail Moonlight Earthlight
Orbit	Orbital elements Distance Perigee and apogee Libration Nodes Nodal period Precession Syzygy New moon Full moon Eclipses Lunar eclipse Total penumbral lunar eclipse Tetrad Solar eclipse Solar eclipses on the Moon Eclipse cycle Supermoon Tide Tidal force Tidal locking Tidal acceleration Tidal range Kordylewski clouds Lunar station
Surface and features	Selenography Terminator Limb Hemispheres Near side Far side Poles North pole South pole Face Maria List Mountains Peak of eternal light Valleys Volcanic features Domes Calderas Lava tubes Craters List A–B C–F G–K L–N O–Q R–S T–Z Ray systems Permanently shadowed craters South Pole–Aitken basin Regolith swirls Rilles Wrinkle ridges Rocks Lunar basalt 70017 Changesite-(Y) Water Space weathering Micrometeorite Sputtering Quakes Transient lunar phenomenon Selenographic coordinate system
Science	Observation Libration Lunar theory Origin Giant-impact hypothesis Theia Lunar magma ocean Geology Timescale Late Heavy Bombardment Lunar meteorites KREEP Volcanism Experiments Lunar laser ranging ALSEP Lunar sample displays Apollo 11 Apollo 17 Lunar seismology
Exploration	Missions Apollo program Artemis program Explorers Probes Landing Colonization Moonbase Tourism Lunar habitation Lunar resources
Time-telling and navigation	Lunar calendar Lunisolar calendar Month Lunar month Nodal period Fortnight Sennight Lunar station Lunar distance
Phases and names	New Full Names Crescent Super and micro Blood Blue Dark Wet Tetrad
Daily phenomena	Moonrise Meridian passage Moonset
Related	Lunar deities Lunar effect Earth phase Moon illusion Pareidolia Man in the Moon Moon rabbit Craters named after people Artificial objects on the Moon Memorials on the Moon Moon in science fiction list Apollo era futuristic exploration Hollow Moon Moon landing conspiracy theories Moon Treaty "Moon is made of green cheese" Natural satellite Double planet Lilith (hypothetical second moon) Splitting of the Moon
Category