NASA Mars Rover has a new Pet Rock for the ride

This story is part Welcome to Marsour series exploring the red planet.

NASA’s Perseverance rover turns into carpool for Martian rocks. At the beginning of 2022, the the rover picked up a stone in his left front wheel. That boulder is still in residence, but it looks like the rover now has a new friend, an even bigger boulder that’s made its way into Percy’s right front wheel.

Astrophotographer Simeon Schmauss noticed the new rock in late February and tweeted a mosaic image of the two rocks in the front wheels as seen by Percy’s left and right hazard avoidance cameras mounted low on the rover.

HazCams help keep tabs on the terrain the rover is traversing, and they’re also useful for monitoring wheels and ultimately keeping an eye out for rocky hitchhikers. The new freeloader appears to have first appeared in a raw image returned by the rover on February 27. The camera got a closer, albeit very shaded, view of the rock on March 1.

Percy’s oldest pet rock traveled many miles with the rover and witnessed the collection of rock samples and the creation of the first sample drop on another world. One of the primary goals of the Perseverance mission is to help us understand whether Mars once harbored microbial life. Delivery of the rover’s sample collection to Earth for further study via the future Mars Sample Return mission is a key part of this effort.

The new Wheel Rock may remain, or it may end up falling as Perseverance traverses Jezero Crater. NASA didn’t care about the original rock, saying last year that the piece was “not perceived as a risk.” NASA did not immediately respond to a request for comment.

Mars is a notoriously rocky place, like sister rover Curiosity and its rough wheels can attest. NASA has reworked the design of Percy’s aluminum wheels so they can withstand the rigors of riding in an inhospitable landscape.

Perhaps the lesson here is that the real treasure of Mars exploration is the rock friends we make along the way.