Selfie by NASA's rover Opportunity on Mars in 2011, showing dust covering the solar panels.

NASA’s Opportunity rover took this self-portrait in January 2014; a thick layer of dust is covering its solar panels.Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.

After exploring for 15 years across 45 kilometres of the Meridiani Planum region of Mars, NASA’s Opportunity rover is officially dead.

The elderly space robot has not been heard from since 10 June 2018, when a massive dust storm blocked the Sun’s rays from reaching Opportunity’s solar panels. Mission controllers at the Jet Propulsion Laboratory (JPL) in Pasadena, California, have tried to contact it hundreds of times since then, using different methods.

On the evening of 12 February, they sent a final set of commands to Opportunity, asking it to respond. There was no answer.

“I declare the Opportunity mission as complete,” said Thomas Zurbuchen, NASA’s associate administrator for science, at a press briefing on 13 February.

There is little hope that the rover will revive. Some at NASA had thought that winds might blow away the dust that had accumulated on Opportunity’s solar panels, allowing them to work again — but the windy season at Meridiani has come and gone. “We needed a historic dust storm to finish this historic mission,” said deputy project scientist Abigail Fraeman of JPL.

The rover will now experience the deep freeze of a Martian winter, with temperatures too cold for Opportunity to survive without electrical help from its solar panels.

Emotions ran high at mission control on the evening of the final contact attempt. “There was silence. There were tears. There were hugs,” tweeted Tanya Harrison, a Mars scientist at Arizona State University in Tempe.

Lasting legacy

Launched in July 2003, Opportunity landed in Meridiani Planum in January 2004 to carry out a 90-day mission of exploration. It ultimately discovered the most ancient habitable environment on Mars. “That was one of the mission’s most significant discoveries, and it came 11 years into our 90-day mission,” said Steve Squyres, the mission’s principal investigator and a planetary scientist at Cornell University in Ithaca, New York.

Opportunity now rests overlooking an area called, fittingly, Perseverance Valley.

Stereo view of the 'Spirit of St. Louis' crater on Mars by the Opportunity rover in 2015.

Opportunity captured this stereo view of Mars’s Spirit of St Louis Crater in March 2015.Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.

The rover’s twin, Spirit, became mired in sand in Gusev Crater, on the other side of the planet, in 2009. NASA declared Spirit’s mission over in 2011. NASA’s Curiosity rover, which landed in 2012 and is nuclear-powered, continues to explore Mars, in Gale Crater. Three more rovers — one each from NASA, the European Space Agency and the China National Space Administration — are expected to launch in 2020, the next time that Earth and Mars will be favourably aligned for spacecraft launches.

Meanwhile, NASA’s newest Mars lander is just getting to work, near the equator and not too far from Curiosity. The stationary InSight probe arrived in November and deployed its French-built seismometer in December, then its German-built heat probe on 12 February. It will listen for seismic activity within the planet, and measure heat flows in the ground, to help scientists better understand the Martian interior.