Washington — The Exploration Rover Opportunity is settling down on a sunny slope for the Martian winter at a place the rover’s watchers have christened Greeley Haven. The sun exposure on the site will help maintain the rover’s solar power during the craft’s fifth winter on the surface of the Red Planet, according to a news release from the Jet Propulsion Laboratory (JPL), where scientists monitor every move of the craft.
Ronald Greeley, a planetary geologist, taught generations of planetary scientists at Arizona State University. He died in 2011, and his JPL associates remembered him and his contributions to their field as they named the sheltered spot where Opportunity will spend the winter. Mars will reach its southern winter solstice on March 30, and daylight hours will be short a few months before and after that date.
In keeping with its almost eight-year history on the Martian surface, the craft will continue to pursue some science at this location.
Plans for research at Greeley Haven include a radio-science investigation of the interior of Mars, which began the first week of January. Opportunity will also inspect the rock outcropping that forms its haven, examining its mineral composition and texture. And as many of us might do while visiting a new place, Opportunity will record a full-circle color panorama of its site, the Greeley Panorama.
The winter worksite is on what JPL calls the Cape York segment of the rim of Endeavour Crater. Opportunity reached the edge of this 22-kilometer-wide crater five months ago after three years of driving from smaller Victoria Crater, which it studied for two years.
Opportunity and its sister craft Spirit completed their three-month primary missions in April 2004, but the sturdy craft, built and designed by NASA engineers, were ready for more exploration. Both rovers made important discoveries about wet environments on Mars in earlier times, environments that may have been favorable for microbial life. Spirit ended communications in March 2010 when its energy declined because the craft was not able to extricate itself from sand and maneuver into a sun-facing position. The craft was crippled because two of its six wheels were knocked out of action during years of roaming the rough terrain of the planet’s surface.
Meantime, NASA has another mission headed to Mars, carrying the most advanced rover ever to land on another planet. The car-sized rover Curiosity began monitoring space radiation after it began the eight-month trip from Earth to Mars in late November. Monitoring the intensity of space radiation pummeling the craft on the journey will help identify the levels of protection human astronauts will need when they make the trip to Mars in the future.
Curiosity carries an instrument called the Radiation Assessment Detector (RAD) that monitors high-energy atomic and subatomic particles from the sun, distant supernovas and other sources. The device also will monitor radiation on the surface of Mars after Curiosity is lowered to the planet surface in August. These first measurements mark the start of the science to be conducted on a mission that will use 10 instruments to assess whether the Martian surface site has been favorable for microbial life at some point in the planet’s history.
The Southwest Research Institute in San Antonio, Texas, together with Kiel University in Kiel, Germany, built RAD with funding from NASA and Germany’s national aerospace research center.