This is the last time we’ll see a selfie of NASA’s InSight lander on Mars. And judging by the amount of dust covering its solar panels, it’s easy to see why.
The stationary spacecraft captured the image on April 24 using its robotic arm, which will be brought into a final resting position called a “retreat posture” this month. To take a selfie, the arm needs to move several times, and that will no longer be possible.
“Before losing more solar energy, I took some time to record my surroundings and took my final selfie before resting my arm and camera permanently in the saved position,”tweeted the InSight account on Tuesday.
Due to declining power supplies, the mission will cease science operations in late summer. Since landing in November 2018, it has been revealing the mysterious interior of Mars.
InSight’s solar panels are becoming increasingly covered with red Martian dust, despite the creative efforts of the mission team on Earth. This buildup will worsen as Mars now enters winter, when more dust rises into the atmosphere.
These floating particles reduce the sunlight needed to charge the solar panels that power InSight, which is currently working on an extended mission expected to last until December. The mission achieved its main objectives after its first two years on Mars.
InSight’s second full selfie, made up of multiple images taken in March and April 2019, shows dust accumulating on solar panels.
The latest selfie shows the lander covered in much more dust than previous selfies from December 2018 and April 2019.
The module entered safe mode on May 7, when its power levels dropped, causing all but essential functions to cease. The team anticipates that this could happen more frequently in the future as dust levels rise.
The stationary lander can only capture about a tenth of the power supply it had available after landing on Mars in November 2018. When InSight landed, it could produce about 5,000 watt-hours per day on Mars, the equivalent of what an electric oven consumes for one hour and 40 minutes.
Martian whirlwinds didn’t help
Now the lander produces 500 watt-hours a day, enough to power an electric oven for just 10 minutes. If 25% of the solar panels were cleaned, InSight would experience a boost in power sufficient to continue operating.
The spacecraft has seen many dust devils or whirlwinds, but none were close enough to clear the solar panels.
“We expected a dust cleanup like we saw several times on the Spirit and Opportunity rovers,” Bruce Banerdt, InSight principal investigator at NASA’s Jet Propulsion Laboratory, said in a statement. “That’s still possible, but the energy is low enough that our focus is to make the most of the science we can still collect.”
Martian dust impacts NASA’s InSight mission
By late summer, the team will shut down the seismometer, wrap up science operations and monitor what level of power is left in the lander. At the end of the year, the InSight mission will end.
However, the InSight team will still listen for any possible communications from the spacecraft and determine if it could ever be operational again.
The lander’s highly sensitive seismometer, called the Seismic Experiment for Interior Structures, has detected more than 1,300 marsquakes hundreds and thousands of miles away. InSight detected the largest so far, a magnitude 5, on May 4.
Mysteries that InSight will continue to unravel
“Even as we’re starting to get closer to the end of our mission, Mars still offers us some really amazing things to see,” Banerdt said.
The data collected by InSight so far reveals new details about the little-known core, inner layers, and crust of Mars. It also recorded meteorological data and analyzed remnants of the magnetic field that once existed on Mars.
The constant stream of InSight data received by scientists on Earth will stop when the solar cells can no longer generate enough power. But for decades to come, researchers will study InSight’s detections to learn as much as possible about our enigmatic planetary neighbor.