Whoa! Opportunity Discovers Matchless Purplish Rocks at Spectacular Mars Overlook

NASA’s long-lived Opportunity rover has discovered a matchless patch of purplish, blocky rocks at a spectacular mountaintop overlook that are unlike anything encountered before during her amazing 11-year science expedition across the alien terrain of the Red Planet.

Opportunity found the intriguing colored rocks—“different from any ever measured before”—last month while driving to an overlook near the summit of Cape Tribulation to survey “Marathon Valley,” her long-term science destination.

Check out the majestic view from the overlook showing the blocky colored rocks in our photo mosaic shown above, from navcam camera raw images taken on Sol 3948 (March 3, 2015) and assembled by Ken Kremer and Marco Di Lorenzo.

The valley was selected for intensive investigation because it holds a motherlode of Martian mineral treasures altered by ancient flowing water, based on orbital observations from NASA’s robotic invasion fleet.

“It’s named Marathon Valley because the rover will have traveled one marathon’s distance to reach it,” Prof. Ray Arvidson, the rover Deputy Principal Investigator of Washington University, told AmericaSpace.

At the Sol 3948 location, Opportunity was less than 140 yards (128 meters) from surpassing the official Olympic marathon-race distance of 26.219 miles (42.195 kilometers).

The golf-cart-sized rover’s route is zigzaging as the rover team changes the path ahead toward Marathon Valley. So NASA says there is uncertainty about where exactly it will pass the milestone marathon distance.

Multiple types of phyllosilicates clay minerals were detected at “Marathon Valley” from orbital observations gathered by NASA’s Mars Reconnaissance Orbiter (MRO).

The rover reached the Martian mountain peak in January 2015, after an arduous drive of more than 1.5 years.

Barely two months ago, on Jan. 6, 2015, Opportunity accomplished the incredible feat of climbing atop the mountain summit at Cape Tribulation, located along the western rim of Endeavour crater. The peak stands about 440 feet (135 meters) above the local plains around the crater.

Vast Endeavour crater spans some 22 kilometers (14 miles) in diameter.

The six-wheeled robot was heading down slope when scientists noticed the otherworldly rocks in imagery transmitted back to the team on Earth.

“We drove to the edge of a plateau to look down in the valley, and we found these big, dark-gray blocks along the ridgeline,” said Opportunity Project Scientist Matt Golombek of NASA’s Jet Propulsion Laboratory, Pasadena, Calif, in a statement.

So the team decided to take a break from the trek ahead to “Marathon Valley” and altered course to move in for an extended closer look.

“We checked one and found its composition is different from any ever measured before on Mars. So, whoa! Let’s study these more before moving on.”

Scientists directed Opportunity to place the Alpha Particle X-ray Spectrometer instrument, located on the end of Opportunity’s robotic arm, onto a target called “Jean-Baptiste Charbonneau.”

The spectroscopic measurements indicted “relatively high concentrations of aluminum and silicon, and an overall composition not observed before by either Opportunity or its twin rover, Spirit.”

The team had planned to grind into another “blue” target at the site with the Rock Abrasion Tool (RAT) called “Sergeant Charles Floyd.” But scientists deemed it would be too hard and therefore cause excessive wear and tear on the RAT, which must be preserved in good condition for as long as possible.

The target-naming theme in this area derives from the Lewis and Clark expedition.

“Although the rocks are gray, the visible-light spectrum of the Charbonneau type has more purple than most Mars rocks, and the spectrum of the Floyd type has more blue. Of the two types, the bluer rocks tend to lie higher on the ridge,” said NASA.

So on Sol 3955 (March 10, 2015) they simply bumped the rover to another nearby softer rock target named “Sgt. Nathaniel Pryor.”

The RAT grinding operation is now planned for the sols ahead.

Although Opportunity’s mission was only planned to last for 90 Sols, she is now 134 months into her three-month mission. That translates to 44 times beyond the prelaunch design expectation way back in 2003.

As of Sol 3956 (March 11, 2015), Opportunity’s total odometry is over 26.15 miles (42.09 kilometers) since touchdown, on Jan. 24, 2004, at Meridiani Planum.

As of today, March 16, 2015, Opportunity has snapped over 201,544 amazing images on the first overland expedition across the Red Planet.

Despite all these accomplishments, the White House seeks to “Kill Opportunity.” Under the newly-rolled-out NASA budget proposal for Fiscal Year 2016, Opportunity would “cease operations” with funding being “zeroed out” as detailed in my recent AmericaSpace story.

The cost to operate Opportunity was just $14 million during 2014.

Meanwhile younger sister rover Curiosity is taking “bites” from the base of another Martian mountain on the opposite side of the Red Planet. Read all about her new drilling campaign here.

Stay tuned here for continuing developments from Earth’s invasion fleet at Mars.

Ken Kremer

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