In four months, the rock has traveled more than 5.3 miles (8.5 kilometers) across the rugged terrain. It joined the mission during the campaign to explore Jezero Crater, the site of an ancient lake and river delta, in which NASA scientists surveyed rocks from a formation the team refers to as “Máaz.”
The rock accompanied Perseverance north to the Octavia E. Butler landing site before turning west to the remains of a delta the scientists call “Kodiak,” then onward to the western Jezero delta.
Tumbling about in the rover’s wheel, Perseverance’s pet rock is not hurting operations, and it remains to be seen how long the robotic explorer’s new friend will stick around.
If the pet rock falls out and says goodbye to the rover, it will be far from home, surrounded by strange, unfamiliar rocks.
Spirit’s and Curiosity’s pet rocks
Perseverance isn’t the first Mars rover to adopt a pet rock.
The Spirit rover, which was active from 2004 to 2010, had a potato-size rock lodged in its right rear wheel early on in its journey. The stone stalled the wheel, so NASA scientists had to dislodge it.