From divining rod in upturned hands to a satellite in the sky, the technology of locating water has greatly changed. The increased technological sophistication that enables satellites to be used as a water research tool has various payoffs, in outer space and on Earth. Arizona scientists are involved in both kinds of projects. See story at left about a project discovering evidence of water on Mars. For a story about using GRACE satellites to study Earth’s water resources, including the resources of the Colorado River Basin, see Special Projects, page 9. Above photo is of the GRACE satellites --- also called Orbiting Twins --- that is sending back data measuring global water storage. Photo: NASA GRACE Mission, University of Texas Center for Space Research.

Evidence of Water Found on Mars
UA has role in space mission

On Earth we say water is life. On Mars evidence of water shows the potential for life. Scientists therefore have taken special note of recent satellite images showing that water may have existed on Mars for a long enough period of time to create an environment supportive of the evolution of microbial life.

The images are the work of the highest-resolution camera ever to orbit Mars, having 30 centimeters per pixel and capable of showing small features, approximately three feet across. Known as the High Resolution Imaging Science Experiment or HiRISE, the camera is on board NASA’s Mars Reconnaissance Orbiter. University of Arizona planetary science professor Alfred McEwen is the HiRISE principal investigator.

Attracting special attention is the area on Mars known as Candor Chasma, a canyon of craggy terrain, with swirls and slashes of ridges and crevices. The terrain is not unlike areas found along Arizona’s Colorado Plateau.

UA geologist Chris Okubo sees the area’s geological patterns with their deep fractures as evidence that liquid, possibly water or gas, once flowed on ancient Mars and penetrated underground. The contrast of light-colored features crossing dark bands seems to show the chemical alteration of rock caused by the flow of fluids. The fluids would have had to been present for a long period of time for this geochemical processes to take place. Erosion over millions of years then exposed the mineralization that occurred along the underground faults and fissures and that now show in the HiRISE images.

Protected from radiation and atmospheric hazards, the underground rock could have provided a sheltered environment for microbes to develop.

Scientists are also using another satellite tool for studying the surface of Mars for evidence of water. Okubo describes CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) as “sort of a companion instrument to HiRISE.” CRISM is a spectrometer that splits visible and near-infrared light of its images into hundreds of “colors” that identify minerals, especially those likely formed in the presence of water. It can focus on relatively small surface areas of Mars, not much larger than a football field on Earth.

Okubo says CRISM is used to determine the chemical composition of the ground surface. “Using both those data sources we can look at areas where there are some sort of alterations, alterations most likely due to water flow, and try to work out what was the chemistry of the fluids.”

The HiRISE Operations Center at the UA Lunar and Planetary Laboratory is responsible for the majority of the ground data system work for the HiRISE instrument. Observation planning, uplink, downlink, data processing, and instrument monitoring are all performed at HiROC.