Author: Lisa Grossman / Source: Science News
Opportunity has finally run out of, well, opportunities.
After weeks of trying to revive the veteran Mars rover in the wake of a blinding dust storm, NASA has given up on ever hearing from it again.After one last failed attempt to reach Opportunity February 12, NASA officials announced the end on February 13. “I was there with the team as these commands went out into the deep sky,” Thomas Zurbuchen, the associate administrator of NASA’s Science Mission Directorate, said in a news conference at the Jet Propulsion Laboratory in Pasadena, Calif. “I learned this morning that we had not heard back, and our beloved Opportunity remains silent. It is therefore that I am standing here with a sense of deep appreciation and gratitude that I declare the Opportunity mission as complete, and with it the Mars Exploration Rover mission as complete.”
Opportunity landed on Mars in January 2004 for a mission that was supposed to last 90 Martian days. Its twin rover, Spirit, had landed three weeks earlier on the other side of the planet.
Spirit succumbed to a stuck wheel in 2010 (SN: 2/27/10, p. 7). But Opportunity kept going. Over 15 years, the rover found abundant evidence that water once flowed and pooled on the Red Planet’s surface. It also shattered records for planetary exploration and shaped Mars missions for years to come.
But on June 10, 2018 — 5,111 Martian days into its 90-day mission — Opportunity went silent, caught in a massive planetwide dust storm (SN Online: 6/13/18). At first, the rover team hoped Opportunity could ride out the storm and wake up when the skies cleared. But it didn’t.
A few final, Hail Mary attempts to reach Opportunity also failed. The rover’s internal clock may have stopped keeping accurate time, which could mean Opportunity was burning through its battery instead of going into a deep sleep mode at night, says mission engineer Bill Nelson of JPL.
On February 2, the rover team started sending the rover frequent commands to reset its clock. The team also directed the rover to use a backup radio channel to send messages to overhead Mars orbiters, rather than try to talk to Earth directly.
Neither strategy worked. With Martian autumn beginning on March 23, plunging the solar-powered rover into colder and darker days, NASA officially called it quits on February 13.
“Everything is only going to go downhill from here,” says Opportunity deputy project scientist Abigail Fraeman of JPL. “If we hadn’t heard from it when it was windy and there was sun on the solar panels, the odds of hearing from it when it’s dark and not windy are pretty low.”
The rover team is nostalgic and wistful, Fraeman says.
“It’s like you fall in love with a car you’ve been driving since high school,” she says. “It’s sad to have to let go of that machine.”
While mourning Opportunity’s demise, the team is also celebrating its accomplishments. What was expected to be a quick survey of a small area “turned out to be this overland expedition across another planet, with mountains and valleys and vistas and storms and sand dunes, adventure after adventure stretching on for years,” says mission principal investigator Steve Squyres of Cornell University. “Nobody expected that.”
And the adventure has changed Mars science. “Before [Spirit and Opportunity] landed, the Mars mantra was ‘follow the water,’” Fraeman says. “We’ve moved so far beyond that in terms of the kinds of questions we ask about Mars. That wouldn’t be possible without the information from these guys.”
On a mission
In the beginning, though, the rover’s main goal was to find evidence of water on Mars, which it did almost as soon as it opened its eyes. This is one of the first views it saw after landing January 25, 2004, in a small depression named Eagle crater near the Martian equator.
Snapped January 28, the image shows exposed layered bedrock, which the team determined was probably sediments laid down by water. The rocks in Opportunity’s landing site had probably been formed in a long-lived salty sea (SN: 3/27/04, p. 195).
The area around Opportunity’s landing site held another watery secret in the form of these small hematite spheres. They’re so tiny that dozens can crowd into a spot just 3 centimeters across.
The rover team called them “blueberries” because their positions in the sediment reminded some scientists of blueberries in a muffin. On Earth, similar orbs form when minerals dissolved in a stream of groundwater solidify again in a different form (SN: 6/19/04, p. 388).
Opportunity’s instant success led the rover team to call it “Little Miss Perfect.” The rover’s landing was even an interplanetary hole in one, settling smack in the middle of Eagle crater.
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