NASA's Rover's Helps Fingerprint Martian Minerals

'Bite mark' in Martian soil made by Curiosity rover
Image credit: NASA/JPL-Caltech/MSSS

Mars rover Curiosity has completed initial experiments showing the mineralogy of Martian soil is similar to weathered basaltic soils of volcanic origin in Hawaii.  The minerals were identified in the first sample of Martian soil ingested recently by the rover. Curiosity used its Chemistry and Mineralogy instrument (CheMin) to obtain the results, which are filling gaps and adding confidence to earlier estimates of the mineralogical makeup of the dust and fine soil widespread on the Red Planet. 

The identification of minerals in rocks and soil is crucial for the mission's goal to assess past environmental conditions. Each mineral records the conditions under which it formed. The chemical composition of a rock provides only ambiguous mineralogical information, as in the textbook example of the minerals diamond and graphite, which have the same chemical composition, but strikingly different structures and properties. 

David Bish, co-investigator with Indiana University in Bloomington, said, "Much of Mars is covered with dust, and we had an incomplete understanding of its mineralogy. So far, the materials Curiosity has analyzed are consistent with our initial ideas of the deposits in Gale Crater recording a transition through time from a wet to dry environment. The ancient rocks, such as the conglomerates, suggest flowing water, while the minerals in the younger soil are consistent with limited interaction with water." 

During the two-year prime mission of the Mars Science Laboratory Project, researchers are using Curiosity's 10 instruments to investigate whether areas in Gale Crater ever offered environmental conditions favorable for microbial life.

NASA Curiosity Rover Update Briefing 18-10-12

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Martian Surprise From #NASA Curiosity Rover

Image credit: NASA/JPL-Caltech/MSSS

'Jake Matijevic', the first Martian rock the Curiosity rover has reached out to touch presents a more varied composition than expected from previous missions. The rock also resembles some unusual rocks from the Earth's interior.

This image shows red dots are where the Chemistry and Camera (ChemCam) instrument zapped it with its laser on Sept. 21, 2012, and Sept. 24, 2012, which were the 45th and 48th sol, or Martian day of operations. The circular black and white images were taken by ChemCam to look for the pits produced by the laser. The purple circles indicate where the Alpha Particle X-ray Spectrometer trained its view.

The results support some surprising recent measurements and provide an example of why identifying rocks' composition is such a major emphasis of the mission. Rock compositions tell stories about unseen environments and planetary processes.  Edward Stolper of the California Institute of Technology said,  "This rock is a close match in chemical composition to an unusual but well-known type of igneous rock found in many volcanic provinces on Earth. With only one Martian rock of this type, it is difficult to know whether the same processes were involved, but it is a reasonable place to start thinking about its origin."

On Earth, rocks with composition like the Jake rock typically come from processes in the planet's mantle beneath the crust, from crystallization of relatively water-rich magma at elevated pressure.

The wealth of information from the two instruments checking chemical elements in the same rock is just a preview. Curiosity also carries analytical laboratories inside the rover to provide other composition information about powder samples from rocks and soil. The mission is progressing toward getting the first soil sample into those analytical instruments during a "sol" or Martian day.

The pyramid shaped rock was named in memory of Jacob Matijevic (1947-2012), the surface operations systems chief engineer for the Mars Science Laboratory Project who played a critical role in the design of the six-wheeled rover. (See The Story of Jake and a Rock on Mars )

Mars Curiosity Rover Prepares to Study Martian Soil for Signs of Life

Curiosity cuts a wheel scuff mark into a wind-formed ripple to give researchers a better opportunity to examine the particle-size distribution of the material forming the ripple. The rover's right Navigation camera took this image of the scuff mark on the mission's 57th Martian day, or sol (Oct. 3, 2012)

(Image Credit: NASA/JPL-Caltech)

NASA's Curiosity rover is in position on Mars to begin to take its first scoop of soil for analysis. The rover's ability to put soil samples into analytical instruments is central to assessing whether its present location on Mars, called Gale Crater, ever offered environmental conditions favorable for microbial life.

Mineral analysis can reveal past environmental conditions. Chemical analysis can check for ingredients necessary for life. The rover's preparatory operations will involve testing its robotic scooping capabilities to collect and process soil samples. Later, it also will use a hammering drill to collect powdered samples from rocks. To begin preparations for a first scoop, the rover used one of its wheels Wednesday to scuff the soil to expose fresh material.

Curiosity will then scoop up some soil, shake it thoroughly inside the sample-processing chambers to scrub the internal surfaces, then discard the sample. Curiosity will scoop and shake a third measure of soil and place it in an observation tray for inspection by cameras mounted on the rover's mast. A portion of the third sample will be delivered to the mineral-identifying chemistry and mineralogy (CheMin) instrument inside the rover. From a fourth scoopful, samples will be delivered to both CheMin and to the sample analysis at Mars (SAM) instrument, which identifies chemical ingredients.

Curiosity's motorized, clamshell-shaped scoop is 1.8 inches (4.5 centimeters) wide, 2.8 inches (7 centimeters) long, and can sample to a depth of about 1.4 inches (3.5 centimeters). It is part of the collection and handling Martian rock analysis (CHIMRA) device on a turret of tools at the end of the rover's arm. CHIMRA also includes a series of chambers and labyrinths for sorting, sieving and portioning samples collected by the scoop or by the arm's percussive drill.