On Jan. 4, 2004, NASA’s Spirit rover touched down on Mars. As noted by Business Insider, it wasn’t long before Spirit was joined by its twin, Opportunity.
Both rovers were expected to last just 90 days in the punishing and dusty Martian landscape. Remarkably, Spirit continued operations until 2010, and the Opportunity rover remained online and active until June 2018, when a massive dust storm swept the craft into darkness. While NASA teams still hold out hope for the rover’s rebirth, its epic 15-year mission may finally be over.
Back in action or down for the count, it’s worth examining some of the most significant findings from Opportunity’s extraordinary years of Mars exploration.
From their first moments on Mars, both rovers were busy. According to a Space Flight Insider editorial, one key discovery by Opportunity (and its twin) was the presence of Earth-like clouds; the rovers took photographs and sent them back home as proof. Opportunity also discovered the first meteorite on another planet, a basketball-sized piece of iron and nickel, and helped create a detailed temperature profile of Mars that showed evidence of rising warm air “thermals.”
And just a few months after landing, the Opportunity rover discovered “blueberries” — tiny, round, iron-rich spheres scattered across the ground. While no perfect analogues for these objects exist on Earth, according to planetary scientist Briony Horgan of Purdue University (as quoted in a recent Space.com piece), “The fact that they’re there tells us a lot of liquid water moved through these rocks over time.”
Water, Water Everywhere
Opportunity’s biggest contribution to Martian science — and human imagination — was evidence for the existence of neutral-pH water that could have supported ancient microbial life. As noted by NASA, Opportunity discovered water-friendly mineral hematite along with evidence that the ancient water was highly acidic.
In 2011, NASA reported that they found gypsum-veined rocks. The likely cause? Flowing water that ran through rock fractures to deposit the mineral. And in 2013, Opportunity discovered the most compelling signs of Mars’ watery past: clay minerals formed in neutral-pH water. As noted by NASA, “This environment at Endeavor Crater once had the friendliest conditions for ancient microbial life.” Not bad for a spacecraft that wasn’t supposed to last more than three months.
Silence and the Storm
On June 10, 2018, Opportunity went silent as a massive dust storm swept over Mars’ Perseverance Valley. Despite six months of silence, “Oppy’s” team still holds out some hope as the dust dies down and winds pick up on the Red Planet, potentially clearing Opportunity’s solar panels and bringing it back to life. According to Opportunity Deputy Principal Investigator Ray Arvidson in a recent Space.com article, the team “will continue to actively try and communicate with Opportunity at least through January,” and is preparing a proposal that will refocus the rover’s efforts if it does come back online.
Even if this is the end for Opportunity, Mars exploration continues. NASA reported that Curiosity is still operating after five years of service, and the Space Agency landed the newest Mars craft, InSight, on Nov. 26, 2018.
The next step for space exploration? Sending astronauts to establish off-world settlements. Both the moon and Mars are potential candidates — the moon offers compelling arguments for distance, “good science” and commercialization. It’s the safer, simpler choice, but somehow lacks the allure of Mars — Pathfinder, Spirit, Opportunity, Curiosity and now InSight have sparked the twin flames of human imagination and ingenuity.
Perhaps Mars won’t offer the first glimpse of extraterrestrial life; perhaps its secrets don’t run so deep. But it’s a mystery that can’t be ignored, a frontier that drives innovation and speaks to boundless opportunity.