Clavius (crater)

Clavius
	LROC image NASA photo.; (South up)
Coordinates	58°24′S 14°24′W / 58.4°S 14.4°W
Diameter	231 km (144 mi)
Depth	4.76 km (2.96 mi)
Colongitude	15° at sunrise
Eponym	Christoph Klau

Clavius is one of the largest crater formations on the Moon and the second largest crater on the visible near side (very close in size to Deslandres). T. W. Webb described it as "one of the grandest cavities in the Moon, though ill-placed for observation." It is "tolerably circular" and "encompassed by a wall damaged by successive explosions".^[2] It dates to the Nectarian period of the lunar geologic timescale.^[3]^[4] This crater is located in the rugged southern highlands of the Moon, to the south of the prominent ray crater Tycho. It is named for the Jesuit astronomer Christopher Clavius.

Description

Clavius' location toward the southern limb of the Moon causes it to appear oblong due to foreshortening. Its great size makes it visible to the unaided eye as a prominent notch in the terminator about one to two days after the Moon reaches first quarter.

It has a low outer wall in comparison to its size and is heavily worn and pock-marked by craterlets. The rim does not significantly overlook the surrounding terrain making it a "walled depression". The inner surface of the rim is hilly, notched and varies in width with the steepest portion to the south. The rim has been observed to have a somewhat polygonal outline overall.

Crater floor

The floor of Clavius forms a convex plain that is marked by some interesting crater impacts. The most notable of these is a curving chain of craters that begins with Rutherfurd in the south then arcs across the floor in a counterclockwise direction forming a sequence of ever diminishing diameters. From largest to smallest, these craters are designated Clavius D, C, N, J, and JA. This sequence of diminishing craters has proved a useful tool for amateur astronomers who want to test the resolution of their small telescopes.

The crater floor retains a remnant of a central massif, which lies between Clavius C and N. The spectra of the central peak fits an anorthositic gabbro mineralogy, which originated from a depth of 24.5 to 42.4 km.^[5] The relative smoothness of the floor and the low size of the central peaks may indicate that the crater surface was formed some time after the original impact.

Presence of water

In October 2020, NASA confirmed the existence of molecular water near Clavius, at concentrations of up to 412 parts per million.^[6] The water could be trapped into tiny beadlike structures in the soil that form out of the high heat created by micrometeorite impacts.^[7] The water might also be sheltered between lunar soil grains. Another possibility is from very small asteroid strikes, such as a rubble pile from a much more massive "parent" asteroid collision. Pulled apart in its descent to the lunar surface similar to Comet Shoemaker–Levy 9, and hitting the surface in a modest dispersal area with a small mass at low, oblique impact angle and bouncing could allow some water to remain in the lithic matrix. The carbonaceous chondrite class is often water-rich, and the CI sub group are as much as 22% water.

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 Clavius.

Clavius	Latitude	Longitude	Diameter
C	57.7° S	14.2° W	21 km
D	58.8° S	12.4° W	28 km
E	51.5° S	12.6° W	16 km
F	55.4° S	21.9° W	7 km
G	52.0° S	13.9° W	17 km
H	51.9° S	15.8° W	34 km
J	58.1° S	18.1° W	12 km
K	60.4° S	19.8° W	20 km
L	58.7° S	21.2° W	24 km
M	54.8° S	11.9° W	44 km
N	57.5° S	16.5° W	13 km
O	56.8° S	16.4° W	4 km
P	57.0° S	7.7° W	10 km
R	53.1° S	15.4° W	7 km
T	60.4° S	14.9° W	9 km
W	55.8° S	16.0° W	6 km
X	60.0° S	17.6° W	7 km
Y	57.8° S	16.0° W	7 km

In popular culture

Clavius Base, the site of an American lunar administrative facility in the movie 2001: A Space Odyssey^{[citation needed]}
Time-travel facility located under Clavius in the 2015 Madeira Desouza novel entitled Baja Clavius: Moon Men Deep Inside^[8]
The location of the fictional Tranquility Base Hotel & Casino in the Arctic Monkeys song "Four Out of Five"^{[citation needed]}

References

^ Williams, Kevin K.; Zuber, Maria T. (January 1998). "Measurement and Analysis of Lunar Basin Depths from Clementine Altimetry". Icarus. 131 (1): 107–122. Bibcode:1998Icar..131..107W. doi:10.1006/icar.1997.5856.
^ Webb, Rev. T. W. (1962). Celestial Objects for Common Telescopes (6th revised ed.). Dover. pp. 132–133, 154–159. Reprint: ISBN 978-0-486-20917-3
^ Byrne, Charles J. (2015). The Moon's Largest Craters and Basins: Images and Topographic Maps from LRO, GRAIL, and Kaguya. Physics and Astronomy. Springer. pp. 8–9. ISBN 978-3-319-22032-1.
^ 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. See Table 9-4.
^ Cahill, J. T. S.; et al. (September 2009). "Compositional variations of the lunar crust: Results from radiative transfer modeling of central peak spectra". Journal of Geophysical Research. 114 (E9) E09001. Bibcode:2009JGRE..114.9001C. doi:10.1029/2008JE003282.
^ "NASA's SOFIA Discovers Water on Sunlit Surface of Moon". NASA. October 26, 2020. Retrieved October 27, 2020.
^ The water could be trapped into tiny beadlike structures in the soil that form out of the high heat created by micrometeorite impacts.
^ "ANNOUNCEMENT/GIVEAWAY: Baja Clavius, by Madeira Desouza – Queer Sci Fi". 7 June 2019.

Sources

Wood, Chuck (2007-08-06). "Smooth Stuff". Lunar Photo of the Day. Retrieved 2007-08-06.
Andersson, L. E.; Whitaker, E. A. (1982). NASA Catalogue of Lunar Nomenclature. NASA RP-1097.
Blue, Jennifer (July 25, 2007). "Gazetteer of Planetary Nomenclature". USGS. Retrieved 2007-08-05.
Bussey, B.; Spudis, P. (2004). The Clementine Atlas of the Moon. New York: Cambridge University Press. ISBN 978-0-521-81528-4.
Cocks, Elijah E.; Cocks, Josiah C. (1995). Who's Who on the Moon: A Biographical Dictionary of Lunar Nomenclature. Tudor Publishers. ISBN 978-0-936389-27-1.
McDowell, Jonathan (July 15, 2007). "Lunar Nomenclature". Jonathan's Space Report. Archived from the original on 2012-02-08. Retrieved 2007-10-24.
Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B. (1971). "Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU". Space Science Reviews. 12 (2): 136–186. Bibcode:1971SSRv...12..136M. doi:10.1007/BF00171763. S2CID 122125855.
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.
Whitaker, Ewen A. (1999). Mapping and Naming the Moon. Cambridge University Press. ISBN 978-0-521-62248-6.
Wlasuk, Peter T. (2000). Observing the Moon. Springer. ISBN 978-1-85233-193-1.

External links

Video by Seán Doran of sunset on Clavius, based on LRO data (see album for more)

[Williams_Zuber_1998-1] Williams, Kevin K.; Zuber, Maria T. (January 1998). "Measurement and Analysis of Lunar Basin Depths from Clementine Altimetry". Icarus. 131 (1): 107–122. Bibcode:1998Icar..131..107W. doi:10.1006/icar.1997.5856.

[Webb_1962-2] Webb, Rev. T. W. (1962). Celestial Objects for Common Telescopes (6th revised ed.). Dover. pp. 132–133, 154–159. Reprint: ISBN 978-0-486-20917-3

[Byrne_2015-3] Byrne, Charles J. (2015). The Moon's Largest Craters and Basins: Images and Topographic Maps from LRO, GRAIL, and Kaguya. Physics and Astronomy. Springer. pp. 8–9. ISBN 978-3-319-22032-1.

[Wilhelms_et_al_1987-4] 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. See Table 9-4.

[Cahill_et_al_2009-5] Cahill, J. T. S.; et al. (September 2009). "Compositional variations of the lunar crust: Results from radiative transfer modeling of central peak spectra". Journal of Geophysical Research. 114 (E9) E09001. Bibcode:2009JGRE..114.9001C. doi:10.1029/2008JE003282.

[6] "NASA's SOFIA Discovers Water on Sunlit Surface of Moon". NASA. October 26, 2020. Retrieved October 27, 2020.

[7] The water could be trapped into tiny beadlike structures in the soil that form out of the high heat created by micrometeorite impacts.

[8] "ANNOUNCEMENT/GIVEAWAY: Baja Clavius, by Madeira Desouza – Queer Sci Fi". 7 June 2019.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

v t e 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 Black 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