Winds of Mars: Aeolian Activity and Landforms
modern martian placenames are derived from placenames applied
by the early observers of Mars, most notably Schiaparelli, Antoniadi,
and Lowell. They mapped albedo features, real and imagined,
and gave them fanciful names. Many of these classical terms
(marked by "*") were retained even after spacecraft
observations revealed their true nature, usually with the addition
of a geographical-type designator. Selection of geographical
names for all extraterrestrial bodies is the province of the
International Astronomical Union (IAU). Two valuable sources
for information on martian nomenclature are Blunck (1977) and
Masursky et al. (1986).
(ay-OH-lee-an) - Pertaining to the wind, from
the Latin Aeolius, the God of Wind. Also spelled eolian (ee-OH-lee-an),
although I prefer the former, which conforms with both Aeolius
and the Aeolian Islands in the Mediterranean.
Albedo (al-BE-doh) - The ratio of radiation reflected from a
surface to that impinging on the surface. In digital image processing,
256 gray levels, ranging from pure black (0) to pure white (255),
are used to measure the albedo of a surface. From the Latin
albus, meaning white.
Planitia* (ar-CAY-dee-a plan-EE-sha) - A classical
martian placename first used by Schiaparelli in 1882. Arcadia
Planitia is located northwest of Tharsis at approximately 50°,
155°. Arkadia is a district in ancient Greece.
Planitia* (AR-jire plan-EE-sha) - A
classical martian placename first used by Schiaparelli
in 1877. Argyre
Planitia is an 800-km-diameter impact basin located at -50°,
45°. The root word is the Greek argyros meaning silver.
Argyre was a mythical island of silver located near present-day
(BAR-can) - An isolated, crescent-shaped sand
dune. The horns of the crescent point downwind, the direction
of migration. From a Turkish word for sand hill, although detailed
etymology is unclear.
Planitia* (CRIS-see plan-EE-sha) - The martian
plain upon which VL-1 landed. Chryse is the classical name applied
by Schiaparelli in 1877 to an area of high albedo. Chryse was
a mythological gold-rich island in the Thailand area, often
mentioned along with Argyre.
devil - An atmospheric vortex caused by differential
surface heating. Air near the ground is heated by the surface
and rises through cooler air aloft. Dust devils pick up fine
particles from the surface and thus are made visible. Dust devils
on Earth are typically on the order of meters across and are
capable of causing minor damage. Martian dust devils are larger.
(erg) - A very large sand mass; a sand sea.
From a Hamitic word areg or ergh for such a sand sea in the
Planitia* (HEL-las plan-EE-sha) - A classical
martian placename first used by Schiaparelli in 1877. Hellas
Planitia is a 2000-km-diameter impact basin located at -40°,
290°. Hellas is an ancient name for Greece and is also a
district in ancient Greece.
Planum* (hes-PE-ree-a PLAY-num) - Another classical
martian placename used by Schiaparelli in 1877, from the Greek
Hesperia, meaning Western Land, the ancient Greek name for Italy.
- The edge of a planet from the observer’s vantage point.
From the Latin limbus, meaning edge or border.
- Extremely large, composite, barchan sand dune.
pl. montes - A standard IAU feature name, taken from the Latin
mons meaning mountain.
Palus* (OX-ee-a) - A martian placename that
has been retained only as a quadrangle name. Lowell, in 1894,
imagined that a canal he named Oxus (from the Oxus River in
Uzbekistan, now called the Amu-Darya) passed through this area
(15°, 15°), emptying into Oxianus Lacus (Lake of Aral),
with an oasis at Oxia Palus. Antoniadi, in 1903, used the term
Oxia for a region immediately to the north.
Mons (o-LIM-pus) - A term derived from a classical
martian placename, Nix Olympica (snows of Olympus). Mt. Olympus
in northern Greece was the home of the gods in Greek mythology.
Olympus Mons is thought to be the largest volcano in the solar
system, although some features of greater areal extent and possible
volcanic origin occur on Venus. Olympus is visible from Earth
under optimum visibility conditions when summit clouds substantially
increase the local reflectivity, making Olympus one of the very
few classical albedo markings of Mars that turned out to match
a real geologic feature.
(PAL-us) - Swamp. A classical name for certain
regions on the Moon and Mars, akin to “seas.”
(plan-EE-sha) - An IAU geographical feature
name meaning “low plain.”
(PLAY-num) - An IAU geographical feature name
meaning “high plain” or “plateau.”
- Particulate material resulting from rock disintegration, with
no connotation as to composition. Sand ranges in diameter from
62.5 micrometers (very fine) to 2 millimeters (very coarse).
Martian winds will move 160-micrometer particles more readily
than any other size.
Planum* (SOH-liss) - A martian plateau located
at 125°, 90°. It retains the name from Solis Lacus (Lake
of the Sun), a classical albedo feature from the map of Schiaparelli
Planum* - A martian plateau located at -15°,
105°, southeast of Tharsis, from a placename applied in
1958 by the IAU to a portion of Thaumasia. Syria is in close
proximity to Solis Lacus and Phoencis Lacus (named for the Sun
bird); the name was applied to an area near “Sun”-related
names because it was used by Homer in the Odyssey to describe
an island where the Sun turns about.
Major Planitia* (SEER-tiss) - A martian plain
located at 10°, 290°, that retains a classical name
that was applied by Schiaparelli in 1877. Syrtis is one of the
most prominent low albedo features on Mars and is easily seen
with a small telescope. The name is derived from the Gulf of
Sidra off the Libyan coast, whose shape it superficially resembles.
(THAR-siss) - An elevated region on Mars containing
the Tharsis Montes, four extremely large volcanos: Olympus,
Ascraeus, Pavonis, and Arsia. Tharsis is a classical martian
placename used by Schiaparelli in 1877. It is a name thought
to be derived from the Biblical Spanish port of Tartessus, which
was destroyed in 500 B.C.
(thou-MAY-zha) - A classical martian albedo feature named by
Schiaparelli in 1879 after Thaumas, god of clouds. It is only
used today for the Thaumasia Fossae, fossae meaning long narrow
Planitia* - A martian plain located at 40°,
260°. The classical term was applied by Schiaparelli in
1882, using a term for “no where,” an ideal state,
coined by Sir Thomas More in 1516.