Nasa’s InSight lander stops responding after months of declining power

The agency said it has assumed that InSight may have reached its end of operations after previously admitting that dust build-up on its solar panels may be preventing its battery from charging.

While this could be a reason the lander has gone quiet, Nasa acknowledged that it currently has no definitive explanation of why InSight’s energy levels have declined, although it will continue to try and regain contact.

Since landing in November 2018, the probe has been traversing the surface of Mars measuring marsquakes and observing the local weather, powering itself with a pair of solar arrays that soak up energy from the sun.

It was originally only expected to operate for two years so is already running on borrowed time. Nevertheless, as recently as October the probe was still making discoveries when it revealed that a massive meteor strike hit Mars last year scattering large chunks of ice around the crater in which it sits.

Dust build-up is a significant problem for Mars probes due to ongoing erosion on the planet’s rocky landscape. On Earth, dust from eroding rocks tends to be carried away by water and eventually end up on the ocean’s floor, but Mars is notably devoid of water, so all the dust that’s blowing around does not get deposited in the same way.

Just prior to InSight’s landing, Nasa’s previous probe Opportunity lost contact with the Earth after being engulfed in a gigantic dust storm covering at least a quarter of the surface of the planet.

Future missions could use special coatings on solar arrays to make them less adhesive to dust, or even a grid of electrical wires above the arrays that a spacecraft could run a charge through to remove the dust. Another option involves double-sided arrays set on a revolving joint that could flip over every couple of years.

The most recent marsquake sensed by InSight, earlier this year, left the ground shaking for at least six hours, according to Nasa.

InSight recently sent back one last image, shared by Nasa on Twitter on Monday.

Nasa still has two active rovers on Mars: Curiosity, roaming the surface since 2012, and Perseverance, which arrived early last year.