Cichus (crater)

Cichus
	LRO image
Coordinates	33°17′S 21°11′W / 33.29°S 21.18°W
Diameter	39.18 km (24.35 mi)
Depth	2.8 km (1.7 mi)
Colongitude	21° at sunrise
Formation	Eratosthenian
Eponym	Cecco d'Ascoli

Cichus is a lunar impact crater that lies in the southwestern part of the Moon,^[3] at the eastern edge of Palus Epidemiarum.^[4] Just to the northeast and nearly contacting the rim is the lava-flooded crater remnant Weiss.^[5]

This formation dates to the Eratosthenian period on the lunar geologic time scale.^[2] The rim is only slightly worn, although the crater Cichus C lies across the southwestern rim. Sections of the inner wall are terraced, and the western side is somewhat wider than in the east. Several small ridges lie across the interior floor. A ray from the bright crater Tycho to the southeast passes tangentially just to the northeast of the rim.^[6]^[7]^: 111

This formation is named after Italian astronomer Francesco Degli Stabili (Cecco d'Ascoli) (1257-1327).^[1] His name was included in the lunar nomenclature of Italian astronomer Giovanni B. Riccioli in 1651, but he assigned it to the crater now named Capuanus.^[8] Its modern designation was formally adopted by the International Astronomical Union in 1935.^[1]

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 Cichus.^[9]

Cichus^[7]^: 295	Latitude	Longitude	Diameter
A	34.8° S	21.4° W	21 km
B	33.2° S	19.3° W	14 km
C	33.5° S	21.8° W	11 km
F	35.7° S	22.4° W	8 km
G	35.5° S	23.5° W	23 km
H	32.8° S	22.4° W	7 km
J	32.0° S	21.3° W	13 km
K	36.6° S	19.9° W	6 km
N	30.5° S	21.7° W	8 km

References

1 2 3 "Cichus". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program. Retrieved 2017-09-08.
1 2 Zhao, Zixu; et al. (June 2023). "Chronology, composition, and mineralogy of mare basalts in the junction of Oceanus Procellarum, Mare Imbrium, Mare Insularum, and Mare Vaporum". Icarus. 397. id. 115531. Bibcode:2023Icar..39715531Z. doi:10.1016/j.icarus.2023.115531.
↑ Webb, Rev. T. W. (1962). Celestial Objects for Common Telescopes (6th revised ed.). Dover. pp. 132, 154–159. Reprint: ISBN 978-0-486-20917-3
↑ Moore, Patrick (2001). On the Moon. Sterling Publishing Co. p. 198. ISBN 978-0-304-35469-6.
↑ "LAC 111" (PDF). Gazeteer of Planetary Nomenclature. Retrieved 2026-07-07.
↑ Grego, Peter (2005). The Moon and How to Observe It. Astronomers' Observing Guides Series. London: Springer-Verlag. p. 180. ISBN 1-85233-748-6.
1 2 Bussey, B.; Spudis, P. (2004). The Clementine Atlas of the Moon. New York: Cambridge University Press. ISBN 978-0-521-81528-4.
↑ Whitaker, Ewen A. (1999). Mapping and Naming the Moon. Cambridge University Press. pp. 60, 211. ISBN 978-0-521-62248-6.
↑ Grego, P. (2015). "Satellite Crater". In Hargitai, H.; Kereszturi, Á. (eds.). Encyclopedia of Planetary Landforms. New York, NY: Springer. doi:10.1007/978-1-4614-3134-3_328.

Sources

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.

[GPN-1] 1 2 3 "Cichus". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program. Retrieved 2017-09-08.

[Zhao_et_al_2023-2] 1 2 Zhao, Zixu; et al. (June 2023). "Chronology, composition, and mineralogy of mare basalts in the junction of Oceanus Procellarum, Mare Imbrium, Mare Insularum, and Mare Vaporum". Icarus. 397. id. 115531. Bibcode:2023Icar..39715531Z. doi:10.1016/j.icarus.2023.115531.

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

[Moore_2001-4] Moore, Patrick (2001). On the Moon. Sterling Publishing Co. p. 198. ISBN 978-0-304-35469-6.

[LAC-111-5] "LAC 111" (PDF). Gazeteer of Planetary Nomenclature. Retrieved 2026-07-07.

[Grego_2005-6] Grego, Peter (2005). The Moon and How to Observe It. Astronomers' Observing Guides Series. London: Springer-Verlag. p. 180. ISBN 1-85233-748-6.

[Bussey_Spudis_2004-7] 1 2 Bussey, B.; Spudis, P. (2004). The Clementine Atlas of the Moon. New York: Cambridge University Press. ISBN 978-0-521-81528-4.

[Whitaker_1999-8] Whitaker, Ewen A. (1999). Mapping and Naming the Moon. Cambridge University Press. pp. 60, 211. ISBN 978-0-521-62248-6.

[Grego_2015-9] Grego, P. (2015). "Satellite Crater". In Hargitai, H.; Kereszturi, Á. (eds.). Encyclopedia of Planetary Landforms. New York, NY: Springer. doi:10.1007/978-1-4614-3134-3_328.

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