'Greeley Haven' is Winter Workplace for Mars Rover
Researchers plan to keep NASA's Opportunity rover busy through Martian winter at a sun-facing site, "Greeley Haven," where a study of the planet's core has begun.
NASA's Mars  Exploration Rover Opportunity will spend the next several months at a site  informally named "Greeley Haven." The name is a tribute to planetary  geologist Ronald Greeley (1939-2011), who was a member of the science team for  the Mars rovers and many other interplanetary missions.The site is  an outcrop that provides a sun-facing slope to aid in maintaining adequate  solar power during the rover's fifth Martian winter.  It also provides targets of scientific  interest for the rover's robotic arm to examine.Closer to the  equator than its twin rover, Spirit, Opportunity did not need to stay on a  sun-facing slope during previous winters. Now, however, Opportunity's solar  panels carry a thicker coating of dust than in the previous winters. Unless an  unlikely wind cleans the panels in coming weeks, the team will use a strategy  employed for three winters with Spirit: staying on a sun-facing slope. For  several months of shortened daylight before and after the southern Mars winter  solstice on March 30, 2012, the sun will pass relatively low in the northern  sky from the rover's perspective, and Opportunity will work on the north-facing  slope.Plans for  research at Greeley Haven include a radio-science investigation of the interior  of Mars, which began this week; inspections of mineral compositions and  textures on the outcrop; and recording a full-circle, color panorama: the Greeley  Panorama. Greeley taught generations of planetary scientists at Arizona State  University, Tempe, until his death two months ago.The  radio-science investigation studies tiny wobbles in the rotation of Mars to  gain insight about the planet's core. It requires many weeks of radio-tracking  the motion of a point on the surface of Mars to measure changes in the spin  axis of the planet.The winter  worksite sits on the "Cape York" segment of the rim of Endeavour  Crater. Opportunity reached the edge of this 14-mile-wide (22-kilometer-wide)  crater five months ago after three years of driving from smaller Victoria Crater,  which it studied for two years.Opportunity and Spirit completed  their three-month prime missions in April 2004 and continued  for years of bonus, extended missions. Both rovers have made  important discoveries about wet environments on ancient Mars that may have been  favorable for supporting microbial life. Spirit ended  communications in March 2010 as its energy declined after losing the use of two  of its six wheels, which prevented it from being able to gain a sun-facing tilt  for its fourth Martian winter.NASA's Jet  Propulsion Laboratory, a division of the California Institute of Technology in  Pasadena, manages the Mars Exploration Rover Project for the NASA Science  Mission Directorate, Washington.  More  information about Opportunity is online at:http://www.nasa.gov/roversandhttp://marsrovers.jpl.nasa.gov.  You can follow the project on Twitter  athttp://twitter.com/MarsRoversand on Facebook athttp://www.facebook.com/mars.rovers.