Released August 12, 2004On Earth, landforms like rivers and mountains
are given names. The names identify a specfic location and also tell the
type of landform; for example: Mount Everest, the Amazon River, the
Pacific Ocean. Landforms on other planets and large moons of our solar
system are also given names that denote the type of feature and the
individual location. It is much easier to discuss the largest volcano in
our solar system by using its name (Olympus Mons) rather than its map
coordinates (Mars, 32N latitude, 135W longitude).
There are strict rules and conventions for assigning landform names to
solar system bodies. The International Astronomical Union (IAU) is in
charge of approving or disapproving submitted names. The online directory
of all (non-Earth) planetary names is located at http://planetarynames.wr.usgs.gov/.
The directory contains information on feature descriptors (Mons =
mountain) and categories of names for feature types (valleys on Mars are
named for the word "mars" in different languages). The list of descriptor
terms can be found at http://planetarynames.wr.usgs.gov/append5.html.
Mythologies of different cultures are often used in selecting names; names
on Mars are primarily from Greek/Roman mythology, while names on Callisto
(a large moon of Jupiter) are from Norse mythology.
As new data is collected for a planetary body, old names may undergo
change. Location names like Olympus are retained, although the lat/long
location may be shifted. The usual change is in the descriptor type.
Better images may show that a different descriptor gives more accurate
information about the landform type; for example, what previously looked
like a featureless plain (planitia) in higher resolution is shown to be a
huge set of lava flows (fluctus). The THEMIS images shown here will
illustrate how some Mars names may need to be updated, while others are
still very accurate descriptors of the landforms.
Tartarus Montes
- Mons/Montes: mountains
- Tartarus: In Greek myth, the lowest part of Hades. Zeus
imprisoned the Titans in Tartarus.
The small hills and ridges in this VIS image are the montes of the
Tartarus region of Mars.
Nomenclature Fact of the Day: Planetary nomenclature is
international in scope; names are chosen from countries and cultures
from all over the world, and they are evaluated by international groups
of experts before they are approved by the IAU.
Image information: VIS instrument. Latitude 15.4, Longitude 172.7 East
(187.3 West). 19 meter/pixel resolution.
Note: this THEMIS visual image has not been radiometrically nor
geometrically calibrated for this preliminary release. An empirical
correction has been performed to remove instrumental effects. A linear
shift has been applied in the cross-track and down-track direction to
approximate spacecraft and planetary motion. Fully calibrated and
geometrically projected images will be released through the Planetary
Data System in accordance with Project policies at a later time.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission
for NASA's Office of Space Science, Washington, D.C. The Thermal Emission
Imaging System (THEMIS) was developed by Arizona State University, Tempe,
in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS
investigation is led by Dr. Philip Christensen at Arizona State
University. Lockheed Martin Astronautics, Denver, is the prime contractor
for the Odyssey project, and developed and built the orbiter. Mission
operations are conducted jointly from Lockheed Martin and from JPL, a
division of the California Institute of Technology in Pasadena.