In planetary nomenclature, a tholus /ˈθoʊləs/ (pl. tholi /ˈθoʊlaɪ/) is a small domical mountain or hill.[1][2] The word is from the Greek θόλος, tholos (pl. tholoi),[3] which means a circular building with a conical or vaulted roof.[4] The Romans transliterated the word into the Latin tholus, which means cupola or dome.[5] In 1973, the International Astronomical Union (IAU) adopted tholus as one of a number of official descriptor terms for topographic features on Mars and other planets and satellites.[6][7] One justification for using neutral Latin or Greek descriptors was that it allowed features to be named and described before their geology or geomorphology could be determined.[8] For example, many tholi appear to be volcanic in origin, but the term does not imply a specific geologic origin.[9] Currently (March 2015), the IAU recognizes 56 descriptor terms.[1] (See Planetary nomenclature.) Tholi are present on Venus, Mars, asteroid 4 Vesta, dwarf planet Ceres, and on Jupiter's moon Io.
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Map of the Tharsis quadrangle showing major features, several of which are tholi. Tharsis contains many volcanoes, including Olympus Mons, the tallest known volcano in the Solar System.
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2001 Mars Odyssey THEMIS mosaic of Ceraunius Tholus (lower volcano) and Uranius Tholus (upper volcano). Ceraunius Tholus is about as high as Earth's Mount Everest.
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Western part of Jovis Tholus, as seen by THEMIS on Mars Odyssey spacecraft. Jovis Tholus is in the Tharsis quadrangle.
Examples of tholi
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edit- ^ a b "Descriptor Terms (Feature Types)". Gazetteer of Planetary Nomenclature. International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). Archived from the original on 2012-05-25. Retrieved 2013-06-24.
- ^ Hargitai H. (2014). "Tholus, Tholi". In H. Hargitai; Á. Kereszturi (eds.). Encyclopedia of Planetary Landforms. Springer New York. p. 1. doi:10.1007/978-1-4614-9213-9_371-1. ISBN 978-1-4614-9213-9. Archived from the original on 2015-01-01.
- ^ Liddell & Scott (1889). An Intermediate Greek-English Lexicon. New York: Harper & Brothers. p. 368.
- ^ "Tholus". Encyclopædia Britannica.
- ^ Simpson, D.P. (1968). Cassell's New Latin Dictionary; Funk & Wagnalls: New York, p. 604.
- ^ De Vaucouleurs G.; Davies M.; Dollfus A.; Koval I. K.; Masursky H.; Miyamoto S.; et al. (September 1975). "The new Martian nomenclature of the international Astronomical Union" (PDF). Icarus. 26 (1): 85–98. Bibcode:1975Icar...26...85D. doi:10.1016/0019-1035(75)90146-3. Archived from the original (PDF) on August 7, 2014.
- ^ Greeley, R. (1994) Planetary Landscapes, 2nd ed.; Chapman & Hall: New York, pp. 35-36.
- ^ Russell, J.F.; Snyder, C.W.; Kieffer, H.H. (1992). Origin and Use of Martian Nomenclature in Mars, H.H. Kieffer et al., Eds.; University of Arizona Press: Tucson, AZ, p. 1310.
- ^ Russell, J.F.; Snyder, C.W.; Kieffer, H.H. (1992). Origin and Use of Martian Nomenclature in Mars, H.H. Kieffer et al., Eds.; University of Arizona Press: Tucson, AZ, p. 1312.
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