The InSight Lander arrived on Mars in 2018 to study the planet’s interior. Its mission ended prematurely in December 2022 after its solar panels were covered in the planet’s ubiquitous dust. NASA’s Mars Reconnaissance Orbiter captured an image of InSight recently and will continue to do so as the Martian dust slowly and inexorably reclaims the lander.
NASA and the DLR sent the InSight lander to Mars to study the planet’s interior. Though the lander’s mole instrument wasn’t able to complete its work, the mission is still considered a success. It detected more than 1,000 Marsquakes, which helped scientists understand Mars’ crust, mantle, and core. It also measured the frequency of meteoroid impacts and uncovered some information on the planet’s thermal evolution.
While the mission was pronounced finished in December 2022, mission personnel continued listening for signals from InSight in case the wind cleared dust from its panels. That effort will also soon end.
Now, the 358-kilogram (789 lb) spacecraft sits in its final resting place in Elysium Planitia. Barring some hyper-futuristic, impossible-to-foresee archaeological rescue expedition, the lander will never move. It’s stranded there, waiting to be imaged repeatedly by the Mars Reconnaissance Orbiter (MRO) and its HiRISE camera.
However, perhaps unexpectedly, InSight still has more to offer. Researchers say that by monitoring the way dust collects on the lander and moves around it, they can learn about Mars’ ubiquitous dust. That will help researchers better understand the planet and prepare more thoroughly for future missions.
“It feels a little bittersweet to look at InSight now.”
Ingrid Daubar, InSight Science Team Member, Brown University
“Even though we’re no longer hearing from InSight, it’s still teaching us about Mars,” said science team member Ingrid Daubar of Brown University in Providence, Rhode Island. “By monitoring how much dust collects on the surface — and how much gets vacuumed away by wind and dust devils — we learn more about the wind, dust cycle, and other processes that shape the planet.”
Martian dust is full of iron oxides, which give the planet its red appearance. It’s very fine and can be lifted high into the atmosphere during Mars’ global dust storms. It affects the planet’s weather and climate.
It’s a hazard for landers and rovers. InSight isn’t the only mission to succumb to it. Spirit and Opportunity also struggled with Martian dust before being defeated by it. Landers and rovers need to be protected from it. It can cover solar panels, rendering them ineffective. It can foul unprotected moving parts, contaminate science instruments, and cause problems with electronics and thermal control.
Martian dust is slightly magnetic due to its iron content, making it quite different from Earth dust. Scientists are concerned that its electrostatic properties might make it stick to surfaces and be difficult to remove. It could cling to some components in unanticipated ways.
There are unanswered questions about Mars’ dust. For instance, scientists don’t know exactly how it all formed or when. Are we seeing only ancient dust? Or is some of it newly created? Scientists aren’t certain how it becomes electrically charged during storms, whether it’s toxic and to what degree, or how exactly it’s transported around the planet during storms.
While monitoring InSight from space likely won’t answer all these questions, it can still teach scientists some things. One of the things they can observe is dust devil tracks. Back when the lander was still active, scientists matched MRO images of dust tracks near the lander with its wind data. They found that the whirling wind patterns that produce the dust devils subside in the winter and pick up again in the summer.
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InSight is also helping scientists understand how quickly surface craters can be obscured by dust. When the lander touched down in 2018, its retrorockets left marks on the surface akin to craters. By knowing exactly when they were created and watching from orbit as they’re obscured by dust, researchers can learn how quickly impact craters can be erased.
The people behind missions like InSight put a lot of time and energy into them. They’re not only career-defining; each mission advances our collective understanding of nature, including other planets in our Solar System. InSight ended because of dust, not because we had learned all we could from it. So even though watching it from orbit and learning what they can is somewhat satisfying, it no doubt reminds the mission personnel of what went left undiscovered.
“It feels a little bittersweet to look at InSight now. It was a successful mission that produced lots of great science. Of course, it would have been nice if it kept going forever, but we knew that wouldn’t happen,” Daubar said.