Nasa has spotted some cracks on the Curiosity Rover that has been travelling across Martian soil since 2012. The space agency said the six aluminium wheels that support the unmanned explorer are starting to show signs of wear and tear due to the harsh conditions on the red planet.

The mentioned breaks were spotted in the rover's grousers on March 19, after photos from Curiosity were compared to similar grouses from a previous wheel check on January 27. While wheel damage is a regular affair, the two broken treads this time reflect the first sign of deeper wear.

The agency has however, said the Rover should be able to travel the required distance to complete its planned mission.

"All six wheels have more than enough working lifespan remaining to get the vehicle to all destinations planned for the mission," said Curiosity Project Manager Jim Erickson at NASA's Jet Propulsion Laboratory.

The Curiosity Mars rover has been treading across Mars for over four-and-a-half years without a major overhaul. It has travelled nearly 16 km on Mars since landing in mid-2012. It is currently stationed in an area known as the Murray formation in the region of Mount Sharp, located in the Gale crater, which was the Curiosity's landing site.

Mars curiosity rover
Grousers on the left middle wheel of NASA's Curiosity Mars rover broke during the first quarter of 2017 NASA/JPL-Caltech/MSSS

The Rover is currently examining sand dunes partway up a geological unit called the Murray formation. Its planned destinations ahead include the hematite-containing "Vera Rubin Ridge," a clay-containing geological unit above that ridge, and a sulfate-containing unit above the clay unit.

The Curiosity's design will serve as the basis for the planned Mars 2020 rover mission.