Department of Climate and Space Sciences and Engineering in the College of Engineering at the University of Michigan


CLaSP researchers comment on Mars rover Opportunity longevity

Posted: February 20, 2018

CLaSP researchers comment on Mars rover Opportunity longevity 5,000th Martian sunrise as seen by Opportunity. (NASA/JPL-Caltech/Cornell/Arizona State Univ./Texas A&M)
This past Saturday, the Sun rose over Mars rover Opportunity for the 5,000th time.

Opportunity landed on the red planet on January 25, 2004 for a planned mission duration of just 90 sols. A Martian sol is the equivalent of on Earth day plus forty minutes, while a Martian year lasts nearly two Earth years. Solar-powered Opportunity was initially not expected to last through the long, low solar energy Martian winter. But, the golf cart-sized rover has persisted, staying active through all seasons anduncovering new surprises in the rocky soil of our second-closest planetary neighbor (Venus is first).
Opportunity’s current location is on the inside slope of the western rim of Endeavour Crater. The rover has traveled over 28 miles (45 kilometers) from its landing site during its stay on Mars, and sent back over 225,000 images of the planet.
“[We think] the reason why Opportunity has been able to survive for so long at the surface of Mars, is due to the rover solar panels being cleaned seasonally by wind gusts,” says Climate & Space Professor of Atmospheric Sciences Nilton Renno. “This was completely unexpected when the mission was designed.”
Professor Renno, along with Assistant Research Scientist, Germán Martínez and Research Fellow Alvaro de Vicente Retortillo Rubalcaba, are a part of NASA’s Mars Science Laboratory mission
“As part of the MSL team,’ explains Martínez, “Alvaro and I have been leading the correction of the UV fluxes data from the effects of dust deposition on the UV sensor, which is located on the deck of the Curiosity rover. What we have learned is that, surprisingly, such cleaning is more likely to occur when the atmospheric dust content is the largest (that is, when the atmosphere is "the dirtiest"). This is because the strongest surface wind stresses (most efficient dust lifting from the surface) and highest frequency of dust devils across Mars occur at that time. Such behavior is also expected at the Opportunity rover landing site and at the future InSight lander site.”  
During its Mars residency, Opportunity has sent back invaluable scientific information about the Martian surface and evidence of groundwater in the planet’s past. The rover has since roamed to increasingly larger craters to peer deeper into Martian geological history, arriving at Endeavor Crater in 2011.

"Five thousand sols after the start of our 90-sol mission, this amazing rover is still showing us surprises on Mars," said Opportunity Project Manager John Callas, of NASA's Jet Propulsion Laboratory, Pasadena, California. "We've reached lots of milestones, and this [5,000 sunrise] is one more," Callas said, "but more important than the numbers are the exploration and the scientific discoveries."

Read more about Opportunity's adventures and discoveries: