Rock Fractures on Mars Reveal Paths of Ancient
Groundwater
Local planetary geologist Chris
Okubo is on a mission to understand the past roles of groundwater and
faulting on Mars by studying similar locations on Earth. Okubo
works in the Astrogeology Research Program for the U.S. Geological
Survey (USGS) in Flagstaff.
�The presence of liquid water on Mars, whether past or present, is a
key clue to whether Mars ever harbored life,� Okubo said, explaining
his work with NASA�s Mars Reconnaissance Orbiter (MRO), a spacecraft
currently orbiting the red planet. �My research interests are
split equally between understanding deformation on Earth and then
applying this knowledge to other planets.�
Recently, Okubo and colleagues from NASA�s Jet Propulsion Laboratory in
California as well as from Nevada, Utah, and Italy used high-resolution
images from a powerful telescopic camera aboard the MRO to analyze
layered rocks in areas around Mars� equatorial region.
�We were looking at rock fractures called �deformation bands�. We
saw hundreds of small fractures that appear to have directed water
through ancient Martian sandstone that now can be seen on the
surface. This is very exciting, because what we�re seeing is the
visible effect on the color and texture of rock made by extensive
groundwater flow billions of years ago.�
Okubo and his colleagues made their findings in part based on fieldwork
in the Colorado Plateau in Utah and Arizona, which has similar
weathered sandstone that exposes ancient deformation bands. The
rock formations of the Colorado Plateau are generally valued by
planetary geologists as accessible study sites for comparison to Mars.
Deformation bands commonly form in sandstone as dense clusters of
small-scale faults within deformed rocks. For comparison to the
newly-observed Mars features, Okubo and his colleagues studied the
deformation bands of the Navajo and Wingate Sandstones.
�Since we have an emerging understanding of how groundwater flows along
deformation bands on Earth, this discovery of deformation bands on Mars
is an important link to building our understanding of how ancient
groundwater behaved on that planet,� Okubo explained.
The researchers used images from the High Resolution Imaging Science
Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter.
This camera reveals smaller details on the surface than any previous
camera to orbit Mars. Chris Okubo�s principal work with the MRO
mission is to provide commands to the camera for specific times,
locations and exposures and to participate in analysis of the images.
The mission of the USGS Astrogeology Research Program is to establish
and maintain geologic, scientific and technical expertise in planetary
science and remote sensing in order to study and map extraterrestrial
bodies, plan and conduct planetary exploration missions, and develop
new technologies in data processing and analysis, archiving, and
distribution.
The USGS provides
science for a changing world. For more information, visit www.usgs.gov.
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