Mars Nomenclature Geography 441541 F19 Dr Christine M

Mars: Nomenclature Geography 441/541 F/19 Dr. Christine M. Rodrigue

Mars: Nomenclature • Mars Naming Conventions – The International Astronomical Union (IAU) governs planetary nomenclature • New features identified, tentatively named, and the IAU peerreviews the name for all planets • Working Group for Planetary System Nomenclature • Once approved, names go into the Gazetteer of Planetary Nomenclature • This is housed at the USGS Astrogeology Research Program: http: //planetarynames. wr. usgs. gov/

Mars: Nomenclature • Mars Naming Conventions – Mars Features: Conventions for Naming Features Albedo Features: Names from classical mythology originally assigned by Schiaparelli and Antoniadi Large craters (craters > ~60 km): Dead scientists who contributed to the study of Mars; writers and others who added to the lore of Mars Small craters (craters < ~60 km): Villages and towns on Earth having populations < 100, 000 Large valles: Name for "Mars" or "star" in various languages Small valles: Classical or modern names of rivers Other features: From a nearby named albedo feature on Schiaparelli or Antoniadi maps Deimos: Authors who wrote about Martian satellites Phobos: Scientists involved with the study of the Martian satellites, and characters and places from Jonathan Swift's Gulliver's Travels

Mars: Nomenclature • Mars: A Whole New Vocabulary! – Why? !? _ Familiar geographical and geological terms are generally too misleading to use in an environment we can’t visit and understand in its own context _ Calling something a “valley” implies the kind of fluvial and glacial erosion responsible for valleys here _ Analogies may not apply, at least not yet _ To avoid that temptation to analogies, the IAU has created a formal vocabulary to use in extraterrestrial contexts _ We have to understand Mars (or any other extraterrestrial object) in its own terms and context Sorry!

Mars: Nomenclature • Mars Features – Vastitas (vastitates) : An extensive, vast plain

Mars: Nomenclature • Mars Features – Planum (plana) : A plateau or high plain • Meridiani Planum seen from Opportunity’s Pancam

Mars: Nomenclature • Mars Features – Planitia (planitiæ) : A low-lying plain or lowland • Elysium Planitia (MEX)

Mars: Nomenclature • Mars Features – Terra (terræ) : An extensive land mass • Arabia Terra (Viking)

Mars: Nomenclature • Mars Features – Chaos: an area of broken or blocky terrain • Aram Chaos (MEX)

Mars: Nomenclature • Mars Features – Cavus (cavi): a hollow or irregular, steep sided depression, often in clusters • Sysiphi Cavi (South Polar Layered Terrain, MGS)

Mars: Nomenclature • Mars Features – Chasma (chasmata): a deep, elongated, steep-sided depression • Ganges Chasma (eastern end of Valles Marineris system)

Mars: Nomenclature • Mars Features – Vallis (valles): a valley or canyon • Ma’adim Vallis (Viking image) • (and Gusev Crater, where Spirit landed)

Mars: Nomenclature • Mars Features – Fossa (fossæ): a long, narrow depression • Claritas Fossæ, in Solis Planum, taken by HRSC on Mars Express

Mars: Nomenclature • Mars Features – Labes: landslide • Valles Marineris (THEMIS)

Mars: Nomenclature • Mars Features – Labyrinthus (labyrinthi): complex of intersecting valleys or ridges • Noctis Labyrinthus map (west of Valles Marineris, east of Pavonis Mons, MRO)

Mars: Nomenclature • Mars Features – Sulcus (sulci): parallel or sub-parallel furrows and ridges • Amazonis Sulci, east of Elysium, Mars Express (MGS)

Mars: Nomenclature • Mars Features – Dorsum (dorsa): a ridge • Dorsum Gordii, Medusa Fossæ area west of Tharsis, THEMIS IR image to left

Mars: Nomenclature • Mars Features – Crater: a circular depression or impact feature _ Crater with ice in Vastitas Borealis, MEX _ Hellas, MOLA _ Phobos, Stickney Crater (Viking)

Mars: Nomenclature • Mars Features – Catena (catenæ): a line or chain of craters or subsidence pits • Coprates Catenæ: impacts or subsidence pitting (MEX)?

Mars: Nomenclature • Mars Features – Mensa (mensæ): mesa or flat-topped prominence with steep sides • Ausonia Mensa in southwest Hesperia Planum (MEX)

Mars: Nomenclature • Mars Features – Lingula (lingulæ): extension of plateau having rounded lobate boundaries • Australe Lingulæ (MEX)

Mars: Nomenclature • Mars Features – Rupes: scarp • Cerberus Rupes, MGS

Mars: Nomenclature • Mars Features – Scopulus (scopuli): a lobate or irregular scarp • Not sure where I got this one or where it is – I suspect Jezero Crater

Mars: Nomenclature • Mars Features – Colles: small hills or knobs • Ariadnes Colles in Cimmeria, MGS, possibly eroded remnants of deposits on crater floor

Mars: Nomenclature • Mars Features – Tholus, tholi: small conical mountain or hill • Uranius Tholus, Tharsis, Viking

Mars: Nomenclature • Mars Features – Mons (montes): large mountain (as in really large, on Mars) • Olympus Mons (Viking)

Mars: Nomenclature • Mars Features – Patera (pateræ): an irregular crater or volcano with scalloped edges _ Alba Patera (now Alba Mons, with patera reserved for craters on top) _ Apollinaris Patera (MGS)

Mars: Nomenclature • Mars Features – Polygonal terrain • South Polar Region, MGS, Hi. RISE

Mars: Nomenclature • Mars Features – Undæ: dunes • Sand Hills of Nili Patera, Syrtis Major, MGS