In 2003, the Opportunity rover was sent to Mars for a 90-day mission in hopes of finding evidence of water, alluding to the possibility of life on the red planet. It landed on the opposite side of the planet from its twin rover Spirit, equipped with the tools to explore rocks and soil and to take photos of the alien landscape. Both robots far outlived their planned missions—Spirit’s life ended in 2010 when it got stuck in a patch of sand, angled so that its batteries couldn’t recharge, and the robot lost communication with Earth. Opportunity went on to break the record for the longest distance driven by any off-Earth wheeled vehicle, crawling a record-breaking 28 miles.

One of NASA’s longest and possibly most successful feats of interplanetary exploration, Opportunity’s journey brought to Earth lessons about the possibility of habitable landscapes and life elsewhere, of engineering perseverance, and of intrepid innovations. There’s no way to refresh your tool set once you’re on another planet, so Opportunity’s team back on Earth had to innovate to keep Opportunity climbing and learning for many years. Clever repurposing made new discoveries possible—when Opportunity lost use of its right front wheel, engineers found workarounds. The rover travelled backwards for some months before the wheel finally returned to a driveable state. NASA’s Jet Propulsion Laboratory housed multiple Mars-like sandpits that scientists used to test ways they could drive the rover across a real sandpit. Once Opportunity began to age, each pit, crater, and hill became a treacherous obstacle.

Across its marathon-length traverse, the rover uncovered hematite, a mineral that forms in water, shown in the false-color images NASA released to the public. And in the Endeavor crater, Opportunity detected suggestions of a water system similar to the drinkable water of Earth’s ponds and lakes. The discoveries made by Opportunity and the dedicated team of scientists behind it demonstrate the similarities between Mars’ landscape and Earth’s, pointing towards the possibility of life on Mars.

In 2018, a storm was brewing on the edge of Mars’ brutal winter season. The storm engulfed the entire planet in thick dust, effectively suffocating Opportunity’s battery recharging technology. Opportunity went into a kind of hibernation, but without any energy to spark its onboard heating, the rover’s internal hardware was at risk of simply splitting in the cold. By June, Opportunity ceased communications with NASA. In dust storms like these, as long as the rover can keep its parts intact, it wakes up when the sky clears to continue its mission.

But even with the dust settling and sky clearing, NASA’s attempts to contact Opportunity were met with complete silence. The dedicated team kept reaching out, but after almost a year of stillness from the lost robot, NASA declared the robot, and its mission, officially dead.

When Opportunity died, many turned to Twitter to publicly mourn and grieve. #ThanksOppy began trending almost immediately after the announcement of Opportunity’s death. Young artists shared comics and drawings and paintings of the beloved rover. There was a tangible sense of sorrow as this long standing connection to the cosmos was severed. These rovers seem vibrantly alive—consistently collecting and communicating data from a place humans never experienced before. Opportunity provided a line of sight, extending our common consciousness onto another planet; in a way, the rover’s death felt like a threat to the opportunity to explore space itself.

NASA engineer Scott Maxwell—Twitter user @marsroverdriver—has said he viewed the rover as a constant, capable joy in his life. For more than a decade of life on Earth, Opportunity was still steadily rumbling along on Mars, and with it, the lives of hundreds of scientists. When Opportunity officially died, Maxwell tweeted: “I drove Spirit and Opportunity for nine years. My cat died. My dad died. I got divorced. And I met the woman I would marry, now the mother of my son. Through all the ups and downs, Opportunity was there.” Opportunity has weaved its way into the identity of many people touched by its existence.

For professors like Samuel Kounaves of the Tufts Chemistry Department, the loss of a rover means something different. In 2003, Kounaves’ proposal to NASA for a robot with chemistry capabilities to “taste” the Martian soil was accepted. Within four years, the Mars Phoenix Lander was launched, and the lives of Kounaves and his students became tightly bound with the life of Phoenix. “It was exciting for all of us,” Kounaves told me as we sat in his office. His walls are plastered with posters about the planets and cosmic chemistry, along with printed photos of smiling students in his lab. The office reflected joyfully on a time of shared learning, of students being part of something a whole planet away from this campus.

Kounaves refers to the Phoenix Lander with affection—“our Phoenix,” he calls it as he discusses the processual death of a robot on Mars. He recounts the story of Phoenix’s last days, as the robot repeatedly tried and failed to reboot, narrating its efforts along the way. When robots communicate like this, it’s easy to anthropomorphize their seemingly valiant efforts. There’s a sense of painful strain against the aging process, with the rovers alone on another planet, narrating their own demise.

But even for people who aren’t so closely connected to spacecraft, humanizing these rovers can be easy. Opportunity’s two camera “eyes” and puppy-like body are immediately reminiscent of movie characters like Pixar’s WALL-E. The dedicated and charming animated rover is extremely close in design to Opportunity, making the comparison almost effortless. Other movies, like Miyazaki’s Castle in the Sky, position the rover as sole protector of a lost landscape. And Opportunity inevitably recalls Star Wars characters like R2-D2, whose charming shape and endearing beeps make the rover out to be more of a companion than a cold robot.  

Susan Napier, Tufts professor of cinema and Japanese culture, points to otherness and the uncanny valley to explain the attraction many feel for Opportunity. The uncanny valley is the uncomfortable space between stylized and realistic. The term is often used in the context of humanoid robots: when their appearance nears but doesn’t reach realism, these robots appear uncanny and eerie. Rather than falling into the uncanny valley like other peculiar, metallic bots, the Opportunity rover’s squat body and tiny head makes it seem endearing and sweet. Opportunity doesn’t feel like a distant, android other; instead, it appears just close enough to pop culture icons to be cute. And when things are cute, people care about them.

Besides Opportunity’s cuteness factor, science writers and news media also humanize elements of spacecraft, often sensationalizing stories to attract the general reader. Opportunity’s poignant last words—“my battery is low and it’s getting dark”—aren’t really the same as the coded signal data that the rover sent before it lost contact. The phrase originated when a Twitter thread by science writer Jacob Margolis went viral. In reality, Opportunity’s transmission was no different than the strings of information sent from any other rovers, but this anthropomorphization of its transmission served to elevate human empathy and brought people to care intensely about the death of a faraway robot.

Scientists themselves sometimes utilize this empathy to help publish their findings—the aforementioned hematite minerals that Opportunity found were nicknamed “blueberries” after NASA assigned them a blue hue on the images released to the public. NASA often manipulates the colors in photos from Mars, and the blue hematite “berries” played a role in promoting the discovery. And Kounaves accidentally publicized his team’s Phoenix Lander findings by stating, at a 2008 conference, that you could grow asparagus on Mars. He was referring to the acidity of Mars’ alkaline-heavy soil, which is comparable to the typical environment for growing asparagus. Mars is not nearly at the watery gardening level required to actually grow any vegetables, but the press took this soundbite and ran with it, just as the public did with Margolis’ poetic translation of Opportunity’s last words.    

This easy humanization of space exploration helps us to forget the great costs of the projects it supports. Marisa Cohn, an anthropologist from Copenhagen, points out in her research that technological infrastructures, like the conglomeration of analytical tools and teams of experts that make a Mars rover, do not approach death as a natural byproduct of time’s passing. Rather, the death of a rover is seen as the end of a careful negotiation of workarounds that reflect our own concepts of aging. “Repairs are made in an effort to decay ‘gracefully’ rather than break catastrophically,” resulting in lifetimes spent on upholding a robot in decay.

In the face of space missions like Opportunity’s, which lasted 14 years and cost a massive $400 million, Kounaves hopes for space exploration missions that are cheaper and more inclusive. “I just wish more students could have that experience,” he says, referring to the flurry of exciting planetary research completed by his students while working on the Phoenix Lander. Inclusivity is a problem in any STEM field, but the inherent expenses associated with space exploration makes involvement in a cosmic project typically limited to a select few. NASA’s Scout program, an initiative for smaller, lower-cost spacecrafts, is what allowed Phoenix to launch and a generation of students to participate in a field otherwise dominated by White men and senior professionals. Space exploration is exciting—the learning experience of working with rovers like Opportunity is an opportunity that more young, ambitious students should have access to.

Opportunity’s death signals more than the loss of a rover. Opportunity extended our line of sight across the cosmos, and even though the rover really was just a robot, the messages it sent from Mars were infused with meaning and sentimentality as its discoveries spread through the public sphere here on Earth. Its journey and life remind us of the very human capability for compassion toward others, and demonstrates that even machines and objects have histories deeply intertwined with culture and collective consciousness.