They tell you to open the door when opportunity knocks, but if the Opportunity rover is knocking on your door, you’re a long way from home — unless your home is on Mars, that is. The Opportunity rover went offline, possibly for the last time, earlier this year when it was exposed to a massive dust storm.
Even if we don’t hear from Opportunity again until we land humans on the red planet, we’re still thankful for all this tenacious little rover has taught us over the years. Let’s take a closer look at the journey of Opportunity.
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Launch Day — July 7, 2003
In July of 2003, Opportunity began its journey alongside Spirit, its sister rover. They arrived in orbit around the red planet at the beginning of 2004. Spirit made landfall on Jan. 4 of that year, and Opportunity began its journey on Jan. 25, three weeks later. Spirit’s launch patch featured Marvin the Martian, while Opportunity’s patch featured Daffy Duck, dressed as Duck Dodgers.
Both of these rovers were designed for a 90-day mission, but that was just the beginning of their journeys.
Liquid Water on Mars
One of the biggest things we’ve been looking for on Mars is water, or evidence that liquid water might have existed at some point there. That was one of the first things Opportunity found near its landing site. There was evidence in the sedimentary rock that liquid water had once existed on the surface of our nearest celestial neighbor. This was hailed as the scientific discovery of the year and is one of the most exciting finds of recent decades.
The rover discovered a number of hard spheres on the surface near where it had landed. Its geologist’s toolbox allowed Opportunity to identify the spheres as hematite. It’s a mineral you’re probably familiar with — nearly every tourist attraction sells Earthbound hematite milled into rings for a couple of dollars.
What made this discovery so exciting is that, at least on Earth, hematite is almost always found in the presence of water. By that logic, water would have had to exist on the surface of the planet at some point in order for the hematite to form. Later, it also discovered the presence of a mineral called jarosite. This mineral only forms in areas where there is acidic water — it is converted from hematite when the mineral is exposed to both heat and sulfuric acid. While humans probably don’t want to drink acidic water, it is an environment where microbes can thrive. It indicates there may have been, at one point in its history, life on Mars.
Opportunity was able to find evidence that water used to exist on the surface of Mars because its landing crater exposed the lower surfaces of the planet. Rather than drilling through thick surface layers, it was decided that Opportunity was going to hop its way across the Martian landscape, traveling from crater to crater, using the meteor strikes that had happened in the past to explore the planet’s history.
From its landing point on the Meridiani Planum, it moved through the Eagle Crater, the Endurance Crater, the Victoria Crater and the Endeavor crater, spending up to 1,000 days traveling the distance between each one. The trip between the Victoria and Endeavor craters was only 21 kilometers, but it took more than 1,000 days to complete.
Trapped in Purgatory
It hasn’t all been sunshine and Martian roses for Opportunity on the surface of Mars. On April 26, 2005, while traveling between the Endurance and Victoria craters, Opportunity got stuck in a sand dune. This dune, dubbed Purgatory Dune, nearly ended the rover’s mission. It took 38 days for the rover to free itself.
It did finally manage to free all six of its wheels from the sand and continue on its way.
Not Much Distance
Opportunity has been traveling for more than a decade now, but it hasn’t made it as far as you might think. On March 24, 2015, NASA celebrated Opportunity’s Marathon status. The rover had traveled 42.195 kilometers — roughly the same distance as a standard marathon.
It doesn’t sound like a huge distance, but for a 15-year-old rover on the surface of an alien planet, it is an amazing achievement.
Saying Goodbye to Spirit
In April of 2010, Opportunity’s sister rover got stuck in another sand dune, similar to the Purgatory dune that trapped Opportunity for more than a month. Scientists at NASA were hopeful they would be able to free the trapped rover the same way they did with Opportunity in 2005. They even started the Free Spirit campaign to allow the rover’s fans to keep up with its trials.
Unfortunately, in spite of the best efforts by Spirit and the team back on Earth, the rover was unable to extricate itself from the sand trap, and went offline permanently on May 25, 2010. Thankfully, Opportunity wouldn’t be alone on the red planet for long. Curiosity landed just over two years later on Aug. 6, 2012.
The End for Opportunity?
Sandstorms have always been a problem on Mars, especially for the Opportunity and Spirit rovers, which relied primarily on solar panels for their power. In June of 2018, a massive sandstorm wrapped more than half the planet, and Opportunity was in its path. The plan was simple — put the rover into sleep mode until the storm passed, and then reactivate it. This would save the rover’s reserve power and allow it to weather the storm.
The storm lasted an astonishing four months, and when it finally dissipated, NASA scientists tried to contact the rover. As of the time of this writing, they have received no response. While they are hesitant to bring the mission to an official end, it isn’t looking good for the robot that has been exploring the surface of Mars for more than a decade, exceeding its original 90-day mission many times over.
Traveling to Mars
In spite of the problems the rovers have faced on the surface of Mars, people are still obsessed with the idea of living on the red planet’s surface. We’re still quite a few years away from sending any astronauts to Mars, but even if the Opportunity rover has finally failed as the result of the massive planet-spanning sandstorm, it proves that human engineering and ingenuity can survive for decades even on the harsh Martian surface. That bodes well for the possibility of future colonization.
We aren’t ready to give up on Opportunity just yet. The little rover might wake up from its long nap and continue to explore the surface of Mars, but even if we have to say goodbye to this rover, we’re thankful for all the things it’s taught us over the years. Without Opportunity, we might not have found signs of water or life on Mars, and that is worth everything — especially if we’re continuing to work toward becoming an interstellar species. Mars could prove to be our second home, and we hope that once we finally reach the red planet, we take the time to find Spirit and Opportunity. They deserve a thank you for all they have contributed to science during their lifetimes.
Featured Image Credit: NASA/ JPL