Two years after NASA retired the InSight lander, scientists are continuing to use the vehicle to learn more about Mars.

InSight was retired in 2022 after it stopped communicating with Earth. The silence started during the lander's extended mission and was expected. Dust had been building up on the lander's solar arrays, preventing its batteries from recharging and eventually leading to its demise. Hopeful that a passing dust devil might clean the arrays, NASA has been listening for a signal from the lander, but with not a peep from InSight over the last two years, that effort will end at the close of 2024.

However, scientists have kept an eye on the lander thanks to images taken by the High-Resolution Imaging Science Experiment (HiRISE) camera aboard NASA's Mars Reconnaissance Orbiter (MRO). Those images have helped scientists better understand how dust works on the Martian surface.

Science team member Ingrid Daubar of Brown University in Providence, Rhode Island said, "Even though we're no longer hearing from InSight, it's still teaching us about Mars.

"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."

Dust plays a critical role in both the atmosphere and landscape of Mars. It can block out light from the Sun and shape the surface. And it has implications for future missions; as well as coating solar panels, the dust can wreak havoc when it gets into mechanical parts.

The imagery has helped scientists understand how quickly marks around craters can fade over time as dust covers them, giving an idea of their age. InSight used rockets to land in 2018, leaving marks visible from orbit. Those marks are fading while InSight's solar panels gradually acquire the same reddish-brown hue as the rest of the Martian surface.

InSight touched down in November 2018. While it was the first to detect marsquakes, according to NASA, its mission did not go entirely to plan. It was also supposed to send a "mole" five meters into the Martian surface to measure the planet's internal temperature, but the soil's unexpected habit of clumping around the device put paid to the experiment, and NASA announced it was giving up trying to coax the mole into Mars at the beginning of 2021

The lander is no longer active yet it continues to prove helpful to scientists studying the movement of dust on Mars.

Daubar said, "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." ®