“Don’t get more energy, almost stop it”

• Ivor Landman

  Online editor

Spirit is stuck in the desert, and Opportunity and Phoenix lose contact with Earth in a dust storm. Mars robots live hard lives, and now the end is in sight for InSight, the lander that has been studying geological activity on the planet since 2018.

“I’m running out of energy” chirp (Team) exhausted lander tonight. “I will resign soon.”

She reminds her the last message of the Opportunity rover (“My battery’s low and it’s getting dark”) that brought tears to mind in 2019. With the InSight lander meeting the same fate—having too much Martian sand on its solar panels preventing it from properly recharging its batteries—the reactions on Twitter became emotional again.

InSight isn’t a bandwagon like Opportunity and its larger successors Curiosity and Perseverance. InSight is a lander on legs whose main mission: to learn more about the interior of Mars.

The Mars robot was given some amazing tools: a hammer, a seismometer to measure earthquakes, and a self-buried “mole” that had to measure how hot or cold it was underground to a depth of 5 metres. But despite two years of trying, the mole was only about 35 cm deep.

Other tools have been more successful. For the first time, Martian earthquakes were measured with a sensitive seismometer placed directly on the surface of Mars. It can also be seen in the last image InSight sent:

In total, InSight has measured more than 1,300 earthquakes large and small. Fifty of them were so heavy that the epicenter could be located on Mars. The probe also provided new data about the different layers that make up the planet, Mars’ liquid core and remnants of a former magnetic field beneath the surface.

The strongest earthquake was measured in May this year, with a magnitude of 4.7, it was five times more powerful than the strongest earthquake to date.

By measuring shocks, planetary scientists are also learning a lot about the formation of Mars.

“For the first time, we’ve observed seismic waves passing through the crust and mantle many times around the planet,” said John Clinton, a Mars researcher and seismologist at a Swiss research institute. “The earthquake was more than 2,000 kilometers away, but the waves were so strong that the seismometer was overloaded.”

“Thanks to InSight, we now have internal measurements of a planet other than Earth,” explains Inge Loes ten Kate, a planetary scientist at Utrecht University. “Mars is a layered planet like Earth and has a core, mantle and crust. Thanks to InSight, we now know better what the crust and upper layer of the mantle look like. And that this composition varies by planet.”

The probe also found evidence of ice beneath the surface. “With all this data, we can make better models of how the planet has changed over billions of years. And even if InSight is now out of work, the new data will allow us to go back in time to not only see Mars, but the planets in general. Get a better understanding.”

Last month, the rover took to Twitter to reflect on its years of activity on Mars. “I was fortunate enough to live on two planets. Four years ago I arrived safely on the second, to the satisfaction of my family on the first. Thanks to my team for this voyage of discovery, I hope you can be proud.”

Even if this is the end of the story for InSight, the other Mars robots keep going. Rover Curiosity (since 2012) is still driving around Gale crater and its persevering successor, in Jezero crater, has just begun an important part of its mission: leaving tubes of Martian grains on Earth. The European rover, which has not yet been launched, should pick up these tubes in a few years and return them to Earth with the help of a space probe.

The creativity of the helicopter is still flying around. The device, equipped with a fast-spinning twin rotor, made its 36th flight on December 10 and has now covered more than 7 km. Soon the helicopter will try to fly over the hills.