“Opportunity on Mars – 8 years and counting!”

Nasa’s Mars Exploration Rover Opportunity landed in Eagle Crater on Mars on Jan. 25, 2004, Universal Time, three weeks after its rover twin, Spirit, had landed halfway around the planet.  Opportunity completed its three-month prime mission in April that year, everything else has been bonus, extended missions. 

Spirit is no longer with us.  But Opportunity carries on. [Image credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.]

This mosaic of images taken in mid-January 2012 shows the windswept vista northward (left) to northeastward (right) from the location where NASA’s Mars Exploration Rover Opportunity is spending its fifth Martian winter, an outcrop informally named “Greeley Haven.”

Opportunity’s Panoramic Camera (Pancam) took the component images as part of full-circle view being assembled from Greeley Haven.

The view includes sand ripples and other wind-sculpted features in the foreground and mid-field. The northern edge of the the “Cape York” segment of the rim of Endeavour Crater forms an arc across the upper half of the scene.

Opportunity is to work through its 5th Martian winter at ‘Greeley Haven’ at Endeavour Crater,  where it arrived in August last year after “a three-year trek that totaled about 13 miles (21 kilometers) across a Martian plain pocked with smaller craters.”  [Image Credit: NASA/JPL-Caltech/UA]

 NASA’s Mars Exploration Rover Opportunity will spend its fifth Martian winter working at a location informally named “Greeley Haven.” This site is an outcrop near the northern tip of the “Cape York” segment of the western rim of Endeavour Crater. It provides a north-facing slope of 15 degrees or more to aid electric output from Opportunity’s solar array. It also presents geological targets of interest for investigating during months of limited mobility while the rover stays on the slope.

This image, covering an area about 2,000 feet (about 600 meters) wide, indicates the location of Greeley Haven on Cape York. The base image of the map is a portion of an image taken by the High Resolution Imaging Science Experiment (HiRISE) instrument on NASA’s Mars Reconnaissance Orbiter, on July 23, 2010. Other image products from this observation are available at http://hirise.lpl.arizona.edu/ESP_018701_1775 .

 As the JPL/Nasa press release on the start of Opportunity’s 9th year of Mars work notes

All six of Opportunity’s wheels are still useful for driving, but the rover will stay on an outcrop called “Greeley Haven” until mid-2012 to take advantage of the outcrop’s favorable slope and targets of scientific interest during the Martian winter. After the winter, or earlier if wind cleans dust off the solar panels, researchers plan to drive Opportunity in search of clay minerals that a Mars orbiter’s observations indicate lie on Endeavour’s rim.

“The top priority at Greeley Haven is the radio-science campaign to provide information about Mars’ interior,” said JPL’s Diana Blaney, deputy project scientist for the mission. This study uses weeks of tracking radio signals from the stationary rover to measure wobble in the planet’s rotation. The amount of wobble is an indicator of whether the core of the planet is molten, similar to the way spinning an egg can be used to determine whether it is raw or hard-boiled.

Other research at Greeley Haven includes long-term data gathering to investigate mineral ingredients of the outcrop with spectrometers on Opportunity’s arm, and repeated observations to monitor wind-caused changes at various scales.

The Moessbauer spectrometer, which identifies iron-containing minerals, uses radiation from cobalt-57 in the instrument to elicit a response from molecules in the rock. The half-life of cobalt-57 is only about nine months, so this source has diminished greatly. A measurement that could have been made in less than an hour during the rover’s first year now requires weeks of holding the spectrometer on the target.

Observations for the campaign to monitor wind-caused changes range in scale from dunes in the distance to individual grains seen with the rover’s microscopic imager. “Wind is the most active process on Mars today,” Blaney said. “It is harder to watch for changes when the rover is driving every day. We are taking advantage of staying at one place for a while.”

And here’s John Callas, Mars Exploration Rovers Project Manager, on the durable Opportunity.  Via JPL News.

Nasa’s Mars Science Laboratory (MSL), with its massive 900kg rover, Curiosity, is on its way.  ETA August 2012.