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New USGS Map of Mars is Most Detailed One Yet

Enhanced color image of a hill in the Candor Colles region of Candor Chasma, Mars. Image is 1 km (0.62 miles) across.

The U.S. Geological Survey released its highest-resolution geologic map of Mars today, and it is the most detailed representation of the Red Planet to date.

As Detailed as if a Field Geologist Surveyed the Red Planet

This new map provides geologic and structural information on layered sedimentary rocks at a scale comparable to what a field geologist would see on Earth, including a precise illustration of a portion of the “Grand Canyon of Mars,” or Valles Marineris. The map provides new targets for continued scientific investigation of past potentially habitable environments on Mars.

The new geologic and structural map uses the highest-resolution, orbiter-based images currently available for Mars – data from the High Resolution Imaging Science Experiment (HiRISE) camera on board the Mars Reconnaissance Orbiter – to illuminate past geological processes in a portion of Valles Marineris. The area analyzed, called western Candor Chasma, is one of the largest canyons in the Valles Marineris canyon system. The resulting map provides the most detailed information of the geology of Mars at a human scale over a broad area of terrain, and is available for download online.

“One can see this map as a preview of the kind of geology humans will conduct when we eventually land on Mars,” said Laszlo Kestay, USGS Astrogeology Science Center Director. “This also demonstrates how the very high resolution topographic and image data we can obtain from Mars’ orbit enables scientific studies on par with rovers and other spacecraft that land on Mars.”

Map Answers Questions on How the Grand Canyon of Mars Formed

The Mariner 9 spacecraft first observed sedimentary rock formations in the canyons of Valles Marineris in 1971, and this new map addresses the outstanding question about the rocks’ environment of formation, or depositional conditions. Previous scientific hypotheses regarding depositional conditions in Candor Chasma include sediment accumulation in lakebeds, volcanic eruptions under glaciers within the canyons and accumulation of wind-blown sand and dust. The HiRISE images show for the first time detailed structures within these rocks that reveal their origin.

“This new map shows that at the time these sediments were deposited, a part of west Candor Chasma, specifically Candor Colles, contained numerous shallow, spring-fed lakes,” said USGS scientist and map author, Dr. Chris Okubo. “These lakes helped to trap wind-blown sand and dust, which accumulated over time and formed the extensive sedimentary deposits we see today.”

These depositional conditions are similar to playa lakes in the American west, such as in Death Valley, California.

Perspective view of the map area looking toward the northeast, with the Candor Colles (low hills) in the foreground.

Perspective view of the map area looking toward the northeast, with the Candor Colles (low hills) in the foreground.

Mars Has Earthquakes Too

The USGS mapping effort further reveals that these wet sediments experienced seismic shaking, called “marsquakes,” which were related to movement along several large faults in the area. The shaking caused the sediments to liquefy and formed features called injectite megapipes, which are now a series of low hills throughout the map area. These low hills are called the Candor Colles, after which the new geologic map is named.

A Place Ripe for Exploring

“This map of the Candor Colles region will open up a new view of soft-sediment deformation in sedimentary deposits on Mars – a place that is ripe for exploring,” said Dr. Marjorie Chan, geology professor at the University of Utah. “Injectite pipes are observed in analogous sedimentary systems on Earth, such as the Jurassic Entrada Sandstone and Carmel Formation, but on Mars they might be an order of magnitude larger than most terrestrial examples. These Mars megapipe features could have been preferential pathways for ancient ground waters.”

A New Standard in Mapping

A unique feature of this map is that its resolution, or scale, is sufficiently detailed that USGS cartographic standards used in terrestrial, Earth-based geologic and structural maps were used – a first for a map of another planet. The geologic map symbols and mapping techniques traditionally used for mapping Mars and other planets were not adequate to capture the unprecedented level of detail in these scientific observations. This map establishes a new standard for future, high-resolution geologic maps of other planets, and allows creation of geologic maps of Mars that are comparable in scale and detail to maps created using traditional geologic field methods on Earth. 

Sample of the map showing the structure and geology of the Candor Colles landforms.

Mars Studies Over Time

The Martian surface has been the subject of scientific observation since the 1600s, first by Earth-based telescopes, and later by fly-by missions and orbiting spacecraft. The Mariner 9 and Viking Orbiter missions produced the first planet-wide views of Mars’ surface, enabling publication of the first global geologic maps (in 1978 and 1986-87, respectively) of a planetary surface other than Earth and its moon. Extremely high-resolution images and data obtained by a new generation of sophisticated scientific instruments, such as those from the HiRISE camera, are allowing more complex, large-scale (zoomed-in) mapping of the Martian surface. 

The production of planetary cartographic products has been a focal point of research at the USGS Astrogeology Science Center since its inception in the early 1960s. USGS began producing planetary maps in support of the Apollo Moon landings, and continues to help establish a framework for integrating and comparing past and future studies of extraterrestrial surfaces. In many cases, these planetary geologic maps show that, despite the many differences between bodies in our Solar System, there are many notable similarities that link the evolution and fate of our planetary system together.

The project was funded by the NASA Planetary Geology and Geophysics Program.

The USGS Astrogeology Science Center 

Thumbnail of the map sheet showing the geologic and structural map, descriptions of geologic units and symbols, stereonets and supplemental maps.

The mission of the USGS Astrogeology Science Center is to serve the Nation, the international planetary science community, and the general public’s pursuit of new knowledge of our Solar System. The Team’s vision is to be a national resource for the integration of planetary geosciences, cartography, and remote sensing. As explorers and surveyors, with a unique heritage of proven expertise and international leadership, USGS astrogeologists enable the ongoing successful investigation of the Solar System for humankind. For more information, visit


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