Scientists free delicate ‘mole’ probe from Mars soil by giving it a whack

‘Insight landed in an area with an unusually thick duricrust – or a layer of cemented soil’

NASA has mended a digging probe on Mars by ordering a rover to hit it with a robotic shovel.

The space agency resorted to brute force after a device that was supposed to dig into the soil became stuck. Called the “mole”, the 15-inch probe got itself wedged firmly into the ground after a patch of the Red Planet turned out to be “clumpier” than expected.

It remained stuck for months while scientists on Earth worked out what to do. Eventually, they instructed Insight, the lander that delivered the mole to Mars, to use its shovel to hit the probe.

NASA said: “A bit of good news from Mars – our new approach of using the robotic arm to push the mole appears to be working. We are excited to see the images and plan to continue this approach over the next few weeks.”

A video released by Nasa showed the shovel being used to tap the side of the digging implement. Scientists ran simulations on Earth, establishing how best to hit it without causing damage to the delicate scientific equipment.

The mole is designed to measure temperatures under the surface of Mars to relay back more information about its core, and how the planet formed.

Insight, which stands for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, landed on Mars in November 2018.

It has been sending back weather reports every day, and has recorded seismic activity on the planet.

Nasa said it did not believe the mole had got stuck because it hit a rock under the surface.

In a statement, the space agency said: “Most of the team remains confident that a rock didn’t cause the mole to rebound. The strategy of ‘pinning’, pressing the robotic arm’s scoop against the side of the mole … helped the mole progress downward.”

The mole was designed to go around any rocks less than four inches in diameter that it encountered underground. Nasa selected an area for it to explore that had few rocks visible, suggesting there would be no problems.

However, the agency said: “Insight landed in an area with an unusually thick duricrust – or a layer of cemented soil. Rather than being loose and sand-like, as expected, the dirt granules stuck together.”