After more than four years of scientific discovery on the Red Planet, NASA’s InSight lander appears to have finally run out of power. NASA officially retired the mission on Wednesday after scientists were unable to make contact with InSight on two consecutive attempts.
The agency’s mission controllers, based out of the Jet Propulsion Laboratory (JPL) in Southern California, will continue to listen for signals from the lander, but they are not hopeful to hear back. InSight last made contact with researchers on December 15.
The lander’s power had been fading over the last several months as Martian dust coated its solar panels, preventing its batteries from recharging. The lander took its final selfie in April and, on December 19, the NASA Twitter account for InSight tweeted one last image of the lander’s view on Mars.
My power’s really low, so this may be the last image I can send. Don’t worry about me though: my time here has been both productive and serene. If I can keep talking to my mission team, I will – but I’ll be signing off here soon. Thanks for staying with me. pic.twitter.com/wkYKww15kQ— NASA InSight (@NASAInSight) December 19, 2022
“We’ve thought of InSight as our friend and colleague on Mars for the past four years, so it’s hard to say goodbye,” says Bruce Banerdt, the mission’s principal investigator, in a statement. “But it has earned its richly deserved retirement.”
Indeed, InSight—which stands for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport—has worked hard since it landed on Mars on November 26, 2018. InSight was equipped with many high-tech instruments that helped it study the Red Planet’s weather and seismic activity, as well as the Martian layers of crust, mantle and core.
With its sensitive seismometer—the last instrument to retain power as the lander’s batteries began to die—InSight recorded an impressive 1,319 marsquakes. Data from these marsquakes allowed researchers to glean more about the planet’s interior makeup. With InSight’s help, they learned that Mars’s crust was thinner than expected and spans a depth of up to 12 to 23 miles, per NASA. They determined the planet’s mantle stretches 969 miles below the surface and that its core has a radius of 1,137 miles.
“It took scientists hundreds of years to measure Earth’s core; after the Apollo missions, it took them 40 years to measure the Moon’s core,” he said in the statement. “InSight took just two years to measure Mars’s core.”
The mission also showed scientists that it’s possible for CubeSats—small, briefcase-sized satellites—to survive in deep space. Two CubeSats called “WALL-E” and “EVE” accompanied InSight to the Red Planet and quickly sent back information to researchers.
Even InSight’s challenges helped provide valuable lessons for scientists back home. The lander carried a self-hammering spike called “the mole,” which engineers had designed to dig 16 feet into the planet to measure its interior heat. However, the unexpectedly clumpy soil near the Mars lander prevented the spike from getting enough traction to penetrate the surface very deeply.
In the end, thanks to some crafty engineering from scientists back on Earth, InSight managed to poke its 16-inch probe just below the surface and was still able to gather information about Martian soil. But the unexpected issues with the spike—and the creative approaches to problem-solving they inspired—will undoubtedly inform future robotic or human missions that hope to dig on Mars.
So, while the hardworking scientists who contributed to the InSight mission say goodbye to the beloved lander, they’re also celebrating its many accomplishments.
“InSight has more than lived up to its name,” says Laurie Leshin, JPL director, in a statement. “Yes, it’s sad to say goodbye, but InSight’s legacy will live on, informing and inspiring.”