Angustus Labyrinthus – False Color


The THEMIS VIS camera contains 5 filters. Data from different filters can be combined in several ways to create a false color image. These false color images can reveal subtle variations in the surface that are not easily identifiable in a single stripe image. Today’s false color image shows part of Angustus Labyrinthus. Angustus Labyrinthus is a unique region near the southern polar cap. In the center of this image, squares formed by intersecting ridges are visible. The feature earned the informal name of the Inca city when it was discovered in the images of Mariner 9 in 1972. Linear ridges are believed to have formed by volcanic and tectonic forces, where magma filled fractures in the subsoil, then erosion revealed the magmatic material.

The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and image coverage must be reduced to accommodate the additional data volume produced by the use of multiple filters. To create a color image, three of the five filter images (each in grayscale) are selected. Each is enhanced in contrast, then converted to an image of red, green, or blue intensity. These three images are then combined to produce a single color image. Since THEMIS color filters do not cover the full range of colors seen by the human eye, a color THEMIS image does not represent the true color. In addition, since each single filter image is enhanced in contrast before being included in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that appears is representative of some color change, however subtle, in the actual scene. Note that the long edges of THEMIS color images usually contain color artifacts that do not represent surface variation.

Orbit number: 85024 Latitude: -81.1964 Longitude: 296.058 Instrument: VIS Captured: 2021-02-13 03:55

Please see THEMIS data citation note for more details on THEMIS image credit.

NASA’s Jet Propulsion Laboratory manages the Mars Odyssey 2001 mission for the NASA Science Mission Directorate, Washington, DC The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS survey is led by Dr. Philip Christensen of Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for Project Odyssey and developed and built the orbiter. Mission operations are carried out jointly by Lockheed Martin and JPL, a division of the California Institute of Technology in Pasadena.


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