by The hard dust of the Red Planet has claimed another spacecraft.
NASA announced Wednesday (December 21) that InSight Landingdesigned to understand its geological life history Mars, completed his mission to the Red Planet. The spacecraft relied on solar power, and after four years on Mars, its sunlight-collecting panels have created too much dust to generate enough power to operate the lander. For months, the InSight team had been waiting for the landing to go silent. Now, the bot has missed two calls home. Scientists last heard from the robot on December 15. NASA will continue to listen, but doesn’t expect to hear anything more from the craft.
“We were actually able to do a lot more than what we claimed and promised to do,” Bruce Banerdt, planetary scientist at NASA’s Jet Propulsion Laboratory (JPL) in California and principal investigator of the InSight mission, told Space. com earlier this year. “I feel that, looking back, this was an extremely successful mission.”
Related: NASA’s Mars InSight lander takes dusty ‘final selfie’ as power fades
InSight was launched in May 2018 and landed six months later. for four years, the $814 million robot quietly listened to the rumblings of the Red Planet.
Unlike its rover siblings Curiosity and Persistence, which focus on assessing the Red Planet’s habitability over time, InSight was designed to look deep into the planet, measuring the layers from the surface to the molten core. The mission was also intended to monitor current geologic activity by feeling for tremors.
And InSight found success on both fronts, even when things didn’t go exactly according to plan.
“Mars itself was amazing: It was more difficult in some ways and it was more imminent in some ways,” Banerdt said. “The parts that were difficult, we were able to extract the information we were looking for by getting smarter about the analysis and so on. we were not expecting that”.
I can’t dig
Mars was particularly challenging when it came to the InSight instrument nicknamed “the mole,” officially known as the Heat Flow and Physical Properties Package. The device was meant to be hoisted 16 feet (5 meters) high and measure how much heat is rising from Mars’ deep core. But no matter what scientists tried, the Mole didn’t could catch the ground at InSight’s landing site, leaving it stuck near the surface.
The difficulty suggests that the terrain beneath InSight is different than in locations previously explored by NASA rovers, according to Sue Smrekar, a planetary scientist at JPL and deputy principal investigator for InSight.
“Based on our understanding of what we saw elsewhere, yes, it should have worked,” Smrekar told Space.com earlier this year. He said he believes the mole would have worked at one of those sites, and that a modified version could work even where InSight landed.
Even without digging properly, the mole continued to gather limited data—but nothing like what scientists had hoped. “It’s not the heat flow that we were really looking for, the big prize, and that was, for me personally, extremely disappointing,” Smrekar said.
The InSight team gave up trying to get the mole digging properly in January 2021, after dealing with problems for nearly two years. “We knew from the beginning that this was a bit of a difficult experiment,” Banerdt said.
Shaking up science
But where the Red Planet’s molehill patch hindered InSight, another area of Mars was surprisingly generous: Cerberus Fossae. The region, which is pockmarked by faults and is about 1,000 miles (1,600 kilometers) away from InSight, has created much more than markers the lander has detected from any other area.
“As far as we understand, there is this one hyperactive region, and it defies the prediction of how cold Mars is, how inactive Mars is,” Smrekar said. “It allows us to see Mars as a non-uniform and old and dead planet.”
InSight also gave scientists a better view of the interior of Mars than any previous mission, with remarkable results. “A lot of things are different than we imagined,” Smrekar said. “Based on the data we had available, we had to make a lot of assumptions about the interior. Now we have this hard data, which gives us a much clearer picture of what’s going on inside the planet.”
The InSight data told scientists that the Martian crust, at least at the rover’s near-equatorial landing site, consists of two different layers: an upper layer about 6 miles (10 km) thick that has been struck by impacts over a deeper layer about 25 miles (40 km) thick. “We didn’t really have a clear picture of these multiple layers in the cortex,” Smrekar said. Even now, she and her colleagues aren’t sure whether the two-layer structure occurs globally or only in certain regions.
Additionally, InSight found that the the core of Mars is much larger than scientists expected. The finding also means the core must contain larger amounts of lighter elements than scientists thought — specifically, more sulfur, perhaps as much as 15 percent to 20 percent, Banerdt said.
“That’s kind of broken our basic models,” Banerdt said. “When you do an experiment and get model-busting data, that’s a real breakthrough.”
(No one is sorry to see the models go. “The planets are much more interesting than our models,” Smrekar said; after all, finding the strengths and weaknesses of current models is the point of any space mission.)
End of line
The InSight team has spent the past few months extracting as much data from the craft as possible. As the robot’s power output dropped, mission staff arranged for the seismometer to run in eight-hour chunks, giving the craft time to recharge its battery.
“Each different kind of marsquake, each additional earthquake, just adds another piece of the story of what’s going on inside Mars,” Smrekar said, noting that the craft caught its biggest earthquake early May, just two weeks ago NASA announced that the mission was nearing its end. “It would be fantastic if we could continue.”
But no mission lasts forever—especially not a solar-powered Mars mission. Red Planet dust is brutal for these spacecraft, accumulating on solar panels and dramatically reducing the arrays’ power output. And the dust is doubly so, as it also seasonally fills the skies, reducing the amount of sunlight that reaches the surface of Mars.
The combination was also made at NASA Opportunity rover in 2018, and now the dust has ended the InSight mission as well.
“It was an amazing spacecraft. It did everything we asked it to do and more,” Banerdt said. “He’s earned his retirement—I like to think of it as retiring and not dying. And he’s going to sit on Mars and enjoy the Martian sunsets for a while after he stops talking to us.”
Email Meghan Bartels at [email protected] or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and up Facebook.
