Patera/ˈpætərə/PAT-ər-ə[1] (plural: paterae/ˈpætəri/PAT-ə-ree)[1] is an irregular crater, or a complex crater with scalloped edges on a celestial body. Paterae can have any origin (volcanic, impact or other), although the majority of them were created by volcanism.[2][3][4] The term comes from Latin, where it refers to a shallow bowl used in antique cultures.[5][6]
This term is used in planetary nomenclature: it is a part of the international names of such features. In such names, it is capitalized and stands after the proper given name (e.g., Pillan Patera). Besides that, it can be used as a description term and applied even to unnamed features.[7][8]
According to some authors, actual usage of the term "patera" had deviated from its definition,[4] and it became not only nomenclatural, but to some extent geological, being used to indicate volcanic origin of the feature.[11][21][4] After Venusian Cleopatra Patera turned out to be an impact crater (instead of a volcanic one, as previously suggested), it was renamed into crater Cleopatra.[22][23][4]
Usually volcanic crater gets a proper name if the volcano itself is low and inconspicuous. Otherwise the volcanic mountain is named, and the crater remains unnamed.[11][4] In some cases, names of Martian volcanic craters with the term "patera" were previously applied to the whole volcano, and it was reflected in values of their sizes given in IAU nomenclatural database. But in 2007, these names were tied to the craters themselves, and the corresponding volcanic mountains obtained names with the terms "Mons" or "Tholus".[24][25][26] An example of such mountains is Alba Mons, which obtained its name 34 years after its crater Alba Patera.[27]
The geological term "highland patera" (a kind of low Martian volcanoes with radially channeled flanks), unlike the nomenclatural term "patera", refers to the whole volcano.[24][25]
Names of paterae
The term "patera" (together with 12 other nomenclatural terms) was introduced into planetary nomenclature in 1973, on XV General Assembly of the International Astronomical Union, when 9 Martian paterae, imaged by Mariner 9 in 1972-1973, were named.[28][29][30]
As of August 2016, 249 paterae or their assemblages are named: 144 on Io, 73 on Venus, 20 on Mars, 6 on Ganymede, 5 on Triton and 1 on Titan.[30] They are named differently on different celestial bodies:[31]
on Titan – after deities of happiness, peace and harmony of various peoples. But actually the only named patera of Titan is named after Norwegian island Sotra, inherited from cancelled name of associated bright spot Sotra Facula;[32]
on Triton – with water-associated names, excluding Greek and Roman.
^ abcTanaka K. L.; Scott D. H.; Greeley R. (1992). "Global stratigraphy". In H. H. Kieffer; B. M. Jakosky; C. W. Snyder; M. S. Matthews (eds.). Mars. University of Arizona Press. pp. 367. ISBN9780816512577.
^ abcdefgHead J. W.; Crumpler L. S.; Aubele J. C.; Guest J. E.; Saunders R. S. (August 1992). "Venus volcanism: Classification of volcanic features and structures, associations, and global distribution from Magellan data". Journal of Geophysical Research. 97 (E8): 13153–13197. Bibcode:1992JGR....9713153H. doi:10.1029/92JE01273. ISSN0148-0227. It is probable that the term "patera" has evolved in usage from that as originally defined and has come to mean any feature similar to Alba Patera on Mars (a broad low shield volcano with an irregular-shaped summit caldera and throughgoing graben).
^"Descriptor Terms (Feature Types)". Gazetteer of Planetary Nomenclature. International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). Archived from the original on 2013-12-10. Retrieved 2014-08-24.
^Бурба Г. А. (1986). К. П. Флоренский; Ю. И. Ефремов (eds.). Номенклатура деталей рельефа спутников Сатурна [Nomenclature of surface features of satellites of Saturn] (in Russian). Москва: Наука. pp. 24–25.
^McKinnon W. B.; Kirk R. L. (1998). "Triton". In P. Weissman; L.-A. McFadden; T. Johnson (eds.). Encyclopedia of the Solar System. Academic Press. p. 418. ISBN9780080573137.
^ abStrobell M. E.; Masursky H. (1990). "Planetary nomenclature". In R. Greeley; R. M. Batson (eds.). Planetary Mapping. Cambridge University Press. pp. 99, 113. ISBN9780521033732.
^"Cleopatra". Gazetteer of Planetary Nomenclature. International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). 2006-10-01. Archived from the original on 2014-05-09. Retrieved 2014-08-24.
^"Alba Mons". Gazetteer of Planetary Nomenclature. International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). 2007-09-19. Archived from the original on 2014-08-08. Retrieved 2014-08-24.
^Бурба Г. А. (1981). К. П. Флоренский; Ю. И. Ефремов (eds.). Номенклатура деталей рельефа Марса [Nomenclature of surface features of Mars] (in Russian). Москва: Наука. pp. 24, 26.
^ ab"Patera, paterae — Nomenclature Search Results". Gazetteer of Planetary Nomenclature. International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). Archived from the original on 2014-08-07. Retrieved 2014-08-24.
^"Sotra Facula". Gazetteer of Planetary Nomenclature. International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). 2012-12-19. Archived from the original on 2012-07-23. Retrieved 2014-08-24.