NASA’s Opportunity rover has just crossed another amazing threshold – passing the 5,000-sol mark on Mars. That is a phenomenal achievement, considering that the plucky little machine was designed for a hopeful lifetime of at least 90 sols (a sol is a Martian day, just slightly longer than an Earth day). To put it another way, Opportunity landed way back in January 2004, and the mission would be considered a great success if it lasted for several months in the harsh Martian climate. But now here it is 2018, and it is still going!
“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.
A Martian year is almost twice as long as on Earth, lasting for 687 Earth days, as compared to 365 days on Earth. But even taking that into account, the rover has now lasted just slightly over 14 Earth years. Not bad for a robotic rover with a nominal lifetime of about 40-45 Earth days (90 Mars sols).
During this time, the rover has traveled 28 miles (45 kilometers) and sent back 225,000 images so far.
“We’ve reached lots of milestones, and this is one more,” Callas said, “but more important than the numbers are the exploration and the scientific discoveries.”
Opportunity also took a celebratory “selfie” mosaic of images on sol 1,500 to capture the moment.
Opportunity’s twin rover, Spirit, which landed the same month and year, was last heard from in early 2010, after becoming stuck in Martian sand the year before, and unable to free itself, running out of power (both rovers are powered by solar panels).
Opportunity has found abundant evidence for a previously more habitable Mars over the years, including ancient playa lakes of salty water and groundwater. Currently, the rover is still exploring an old channel in the rim of Endeavour crater called Perseverance Valley, which scientists think was carved by water a few billion years ago. Mission scientists have seen some interesting features within this valley, such as “rock stripes” similar to those on Earth which result from repeated cycles of the freezing and thawing of wet soil. The stripes have a distinctive appearance, although not quite as pronounced as on Earth, where soil and gravel particles appear to be “organized” into narrow rows, parallel to the slope and alternating between rows with more gravel and other rows with less.
“Perseverance Valley is a special place, like having a new mission again after all these years,” said Opportunity Deputy Principal Investigator Ray Arvidson of Washington University in St. Louis. “We already knew it was unlike any place any Mars rover has seen before, even if we don’t yet know how it formed, and now we’re seeing surfaces that look like stone stripes. It’s mysterious. It’s exciting. I think the set of observations we’ll get will enable us to understand it.”
The Curiosity rover, meanwhile, is still busy exploring Vera Rubin Ridge near the base of Mount Sharp, where it has found interesting crystal formations which may provide more clues about the ancient lake environment which once existed in Gale crater. The rover had also recently found seasonal clues about methane in the Martian atmosphere and studied other odd stick-like formations which could also be crystals or something else.
NASA’s next Mars lander, InSight, is scheduled to launch this spring, with the launch window opening on May 5. InSight is a lander, not a rover, and will focus on probing the deep interior of the planet, including listening for marsquakes, to help scientists understand how Mars formed and evolved. It will arrive at Mars on November 26, 2018.
No one knows how much longer Opportunity will continue its travels, but what an incredible journey it already has been so far.