Press Release

Rocks Tell Stories in Reports of NASA’s Spirit Rover’s First 90 Martian Days

By SpaceRef Editor
August 5, 2004
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Rocks Tell Stories in Reports of NASA’s Spirit Rover’s First 90 Martian Days
08.05.04.spirit.jpg

Scientific findings from the NASA rover Spirit’s first three months on
Mars will be published Friday, marking the start of a flood of
peer-reviewed discoveries in scientific journals from the continuing
two-rover adventure.

Researchers using Spirit’s toolkit of geological instruments from
early January into April read the record from rocks and soils in the
rover’s landing area and found a history of volcanic blanketing,
impact cratering, wind effects and possible past episodes of scant
underground liquid water. Evidence for the water comes from mineral
alteration in the veins, inclusions and coatings of some rocks. Eleven
reports with 120 collaborating authors from around the world lay out
details in the Aug. 6 issue of the journal Science.

  • The Spirit Rover’s Athena Science Investigation at Gusev Crater, Mars (abstract), Science
  • Pancam Multispectral Imaging Results from the Spirit Rover at Gusev Crater (abstract), Science
  • Spirit at Gusev Crater: Plates (abstract), Science
  • Initial Results from the Mini-TES Experiment in Gusev Crater from the Spirit Rover (abstract), Science
  • Surficial Deposits at Gusev Crater Along Spirit Rover Traverses (abstract), Science
  • Wind-Related Processes Detected by the Spirit Rover at Gusev Crater, Mars (abstract), Science
  • Localization and Physical Properties Experiments Conducted by Spirit at Gusev Crater (abstract), Science
  • Textures of the Soils and Rocks at Gusev Crater from Spirit’s Microscopic Imager (abstract), Science
  • Magnetic Properties Experiments on the Mars Exploration Rover Spirit at Gusev Crater (abstract), Science
  • Chemistry of Rocks and Soils in Gusev Crater from the Alpha Particle X-ray Spectrometer (abstract), Science
  • Mineralogy at Gusev Crater from the Mössbauer Spectrometer on the Spirit Rover (abstract), Science
  • Basaltic Rocks Analyzed by the Spirit Rover in Gusev Crater (abstract), Science
  • “This is the first batch,” said Dr. Steve Squyres of Cornell
    University, Ithaca, N.Y., principal investigator for the science
    payload on both Mars Exploration Rovers. “You’ll be seeing a lot more
    publications in months ahead and, no doubt, for many years to come
    based on information from Spirit and Opportunity. These machines just
    keep going and going, so the science just keeps coming and coming.”
    Dr. Jim Garvin, NASA’s Chief Scientist for Mars added, “This is the
    basis for beginning the remarkable scientific legacy of the rovers
    that will not only rewrite our textbooks about Mars, but also pave the
    way for human exploration.”

    The rovers completed three-month primary missions in April, then began
    bonus exploration in extended science missions. “Spirit and
    Opportunity have really done yeoman’s work, still operating after more
    than twice as long as their original assignments. We don’t know how
    much longer they’ll keep working, but while they do we promise to keep
    them busy,” said Jim Erickson, project manager at NASA’s Jet
    Propulsion Laboratory, Pasadena, Calif.

    Both rovers were equipped and targeted to collect evidence about past
    environmental history, especially any history of liquid water, since
    life as we know it depends on water. Spirit is exploring inside Gusev
    Crater, an ancient Connecticut-sized impact basin that was selected as
    a landing site because it may have once held a giant lake fed by flows
    of water though a large valley that empties into the crater.

    The new reports state that, in its first three months, Spirit found no
    evidence of lake-related (lacustrine) deposits. “Any lacustrine
    sediments that may exist at this location within Gusev apparently have
    been buried by lavas that have undergone subsequent impact
    disruption,” says the leadoff paper by Squyres and 49 other rover
    science team members. Spirit has subsequently driven to a different
    location — nearby hills over 3 kilometers (2 miles) away — to
    continue exploring.

    Dr. John Grant of the National Air and Space Museum, Washington, and
    co-authors report that the rocks on the plain that Spirit explored
    during its primary mission increased about fivefold in maximum size as
    the rover got closer to an old 210-meter (690-foot-wide) impact
    crater. The impact that excavated the crater brought volcanic rocks to
    the surface from as deep as 10 meters (33 feet). Several papers give
    evidence that rocks in the area are a volcanic type called basalt and
    bear the mineral olivine. These include reports by Cornell’s Dr. Jim
    Bell with collaborators using Spirit’s panoramic camera and by Dr.
    Dick Morris of NASA Johnson Space Center, Houston, with collaborators
    using the Moessbauer spectrometer. Dr. Hap McSween of the University
    of Tennessee, Knoxville, and co-authors state, “These basalts extend
    the known range of rock compositions comprising the martian crust.”

    Dr. Ken Herkenhoff of Flagstaff, Ariz., offices of the U.S. Geological
    Survey and other scientists using Spirit’s microscopic imager offer
    findings that rocks cut into by the rover’s rock abrasion tool have
    coatings and bright veins apparently from mineral alteration after the
    rocks formed. Dr. Ralf Gellert of Max-Planck-Insitut-fur-Chemie in
    Mainz, Germany, and other users of Spirit’s alpha-particle X-ray
    spectrometer report that bromine in the veins suggests the alteration
    resulted from exposure to water. Dr. Phil Christensen of Arizona State
    University, Tempe, and collaborators using Spirit’s miniature thermal
    emission spectrometer say the rock’s coatings are consistent with
    exposure to moisture while buried. Dr. Ray Arvidson of Washington
    University, St. Louis, and co-authors describe cohesive texture in
    soils and rock coatings, which they suggest could result from brief
    moist periods in the past.

    Magnet experiments indicate almost all sampled dust particles in Mars’
    atmosphere contain magnetic minerals, according to a paper by Dr.
    Preben Bertelsen of the Niels Bohr Institute, Copenhagen, Denmark, and
    others. Dr. Ron Greeley of Arizona State University and co-authors
    found that winds from the northwest grooved some rock surfaces and
    shaped sand ripples in the past. They report that the way rock dust
    accumulates during grinding by Spirit’s rock abrasion tool shows that
    wind still comes from the same direction.

    JPL, a division of the California Institute of Technology in Pasadena,
    manages the Mars Exploration Rover project for NASA’s Science Mission
    Directorate, Washington. Images and additional information about the
    project are available from JPL at http://marsrovers.jpl.nasa.gov and
    from Cornell University, Ithaca, N.Y., at http://athena.cornell.edu .

    SpaceRef staff editor.