The rover used its microscopic imager, Moessbauer spectrometer and alpha particle X-ray spectrometer on the drift material. Then it backed up about 10 centimeters (4 inches), turned, and advanced about the same distance to be in position for thoroughly examining the flaky rock called "Mimi" during sol 42, which will end at 9:18 a.m. Sunday, PST.

Plans call for resuming long daily drives on sol 43 toward the crater nicknamed "Bonneville" on the northeastern horizon.

OPPORTUNITY UPDATE: Rover Says "No" - sol 20, Feb 14, 2004

During Opportunity's 20th sol on Mars, which ended at 8:20 p.m. Friday, PST, the rover told mission controllers "no." Opportunity received commands in the morning to use the microscopic imager at the end of its arm, but the onboard computer judged the requested arm movement to be unacceptable and refused the command.

This was the proper precaution for the rover to take. The arm maneuver had been tested with a simulation at JPL, and engineers subsequently worked on a solution to make the ground testing more accurately predict the rover computer's response to the particular arm-movement conditions involved.

However, with the arm left extended, rather than stowed, after the arm-movement command was refused, the rover also could not make the drive that had been planned for the sol. That drive, to a site selected for soil examination and trenching, was postponed until sol 21, which ends at 9:00 p.m. Saturday, PST.

Observations by the panoramic camera and miniature thermal emission spectrometer were completed successfully on sol 20. The sol's wake-up music was "I Like Dirt," by the Red Hot Chili Peppers, and "Pioneers of Mars," by Karen Linsley and Lloyd Landa.