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| The drive by NASA's Mars rover Curiosity during the mission's 43rd Martian day, or sol, (Sept. 19, 2012) ended with this rock about 8 feet (2.5 meters) in front of the rover [PHOTO: NASA/JPL-Caltech] |
Pasadena, California: NASA's Mars rover Curiosity has driven up to a football-size
rock that will be the first for the rover's arm to examine.
Curiosity is about 8
feet (2.5 meters) from the rock. It lies about halfway from Curiosity's landing
site, Bradbury Landing, to a location called Glenelg. In coming days, the team
plans to touch the rock with a spectrometer to determine its elemental composition
and use an arm-mounted camera to take close-up photographs.
Both the arm-mounted
Alpha Particle X-Ray Spectrometer and the mast-mounted, laser-zapping Chemistry
and Camera Instrument will be used for identifying elements in the rock. This
will allow cross-checking of the two instruments.
The rock has been
named "Jake Matijevic." Jacob Matijevic (mah-TEE-uh-vik) was the
surface operations systems chief engineer for Mars Science Laboratory (MSL) and
the project's Curiosity rover. He passed away Aug. 20, at age 64. Matijevic
also was a leading engineer for all of the previous NASA Mars rovers:
Sojourner, Spirit and Opportunity.
Curiosity now has
driven six days in a row. Daily distances range from 72 feet to 121 feet (22
meters to 37 meters).
"This robot was
built to rove, and the team is really getting a good rhythm of driving day
after day when that's the priority," said MSL Project Manager Richard Cook
of NASA's Jet Propulsion Laboratory in Pasadena, Calif.
The team plans to
choose a rock in the Glenelg area for the rover's first use of its capability
to analyze powder drilled from interiors of rocks. Three types of terrain
intersect in the Glenelg area -- one lighter- toned and another more cratered
than the terrain Curiosity currently is crossing. The light-toned area is of
special interest because it retains daytime heat long into the night,
suggesting an unusual composition.
"As we're
getting closer to the light-toned area, we see thin, dark bands of unknown
origin," said Mars Science Laboratory Project Scientist John Grotzinger of
the California Institute of Technology, Pasadena. "The smaller-scale
diversity is becoming more evident as we get closer, providing more potential
targets for investigation."
Researchers are using
Curiosity's Mast Camera (Mastcam) to find potential targets on the ground.
Recent new images from the rover's camera reveal dark streaks on rocks in the
Glenelg area that have increased researchers' interest in the area. In addition
to taking ground images, the camera also has been busy looking upward.
On two recent days,
Curiosity pointed the Mastcam at the sun and recorded images of Mars' two
moons, Phobos and Deimos, passing in front of the sun from the rover's point of
view. Results of these transit observations are part of a long-term study of
changes in the moons' orbits. NASA's twin Mars Exploration Rovers, Spirit and
Opportunity, which arrived at Mars in 2004, also have observed solar transits
by Mars' moons. Opportunity is doing so again this week.
"Phobos is in an
orbit very slowly getting closer to Mars, and Deimos is in an orbit very slowly
getting farther from Mars," said Curiosity's science team co-investigator
Mark Lemmon of Texas A&M University. "These observations help us
reduce uncertainty in calculations of the changes."
In Curiosity's
observations of Phobos this week, the time when the edge of the moon began
overlapping the disc of the sun was predictable to within a few seconds.
Uncertainty in timing is because Mars' interior structure isn't fully
understood.
Phobos causes small
changes to the shape of Mars in the same way Earth's moon raises tides. The
changes to Mars' shape depend on the Martian interior which, in turn, cause
Phobos' orbit to decay. Timing the orbital change more precisely provides
information about Mars' interior structure.
During Curiosity's
two-year prime mission, researchers will use the rover's 10 science instruments
to assess whether the selected field site inside Gale Crater ever has offered
environmental conditions favorable for microbial life.