Goals: Mission Results

Goal 3: Characterize the Geology of Mars

As on Earth, rocks and minerals on Mars contain clues to the past. Scientific investigations by Spirit and Opportunity tell a story of a sulfate-rich planet that was once wetter and prone to violent explosions from meteorite impacts and volcanoes. At various times, winds blew sand across the surface and water flowed on the surface and soaked the ground. Some of the conditions necessary to sustain life as we know it were present. Whether life ever existed on Mars remains an open question.

20-20 Vision In this panorama, one of many acquired by the Spirit rover since arriving at Mars in 2004, are slopes and summits of the "Columbia Hills," ripples and rover tracks in the sand, black rocks hardened from lava, the floor and distant rim of Gusev Crater, suspended dust in the atmosphere, and other features of Martian geology seen from the top of "Husband Hill." Credit: NASA/JPL-Caltech/Cornell Full Image

Both rovers measured the type and abundance of iron-bearing minerals, some of which are associated with water-driven processes. In this way, Opportunity found the mineral jarosite and Spirit found the mineral goethite. The rovers measured chemical elements, some of which are needed for life, in rocks and soils. They ground holes in weathered rocks, looked beneath the weathered surfaces, and acquired magnified views of textures and soil grains.

Rocks Altered by Water The Spirit rover used a suite of scientific instruments to determine that this rock target, called "Clovis," contained goethite, a mineral that only forms in the presence of water. Spirit also found elevated levels of sulfur, bromine, and chlorine deposited by evaporating water. Credit: NASA/JPL-Caltech/Cornell/Max Planck Institute Full Image

Measuring infrared radiation (heat) associated with specific minerals, the rovers identified and mapped minerals in rocks and soils. Key among these was hematite, an iron-bearing mineral often associated with water originally mapped by the Odyssey spacecraft. After being sent to the same area to get a closer look, Opportunity did indeed find hematite in rock outcrops as well as in high concentrations in the rounded, blueberry-size concretions.

Iron-Bearing Minerals Nodular nuggets at the end of short, stalklike features were one of the more unusual features of a softball-size rock nicknamed "Pot of Gold" by rover scientists. Spirit's scientific instruments determined that the rock contained hematite, a mineral often formed in the presence of water. Credit: NASA/JPL-Caltech/Cornell/USGS Full Image

Each day, the rovers sent images to Earth that include spectacular panoramas of an alien landscape as well as information about color variations (measured by camera filters) in rocks, soils, and sunlight. Like polarized sunglasses that minimize glare yet enhance features in the landscape, these color images have helped scientists map the composition of landforms, geologic structures, rock shapes, and textures. Scientists and students will spend many years analyzing all the data collected by the rovers and investigating the ways in which Mars is similar to yet different from Earth.

Mars Through A Lens, Colorfully Like trail markers for hikers, a series of holes rimmed by red Martian dust marks Opportunity's journey of exploration into the interior of Endurance Crater in this false-color image. The rover's panoramic camera has 13 different color filters. By enhancing the wavelengths seen in different images, scientists can better highlight changing features in the rocks. Credit: NASA/JPL-Caltech/Cornell Full Image