[Rockhounds] Perseverance has a pet rock

[Kreigh Tomaszewski]

How do you choose a rock on Mars? Sometimes you don't—it chooses you.

For the past four months, Perseverance has had an unexpected traveling
companion. Back on sol 341—that's over 100 sols ago, in early February—a
rock found its way into the rover's front left wheel, and since hitching a
ride, it's been transported more than 5.3 miles (8.5 km). This rock isn't
doing any damage to the wheel, but throughout its (no doubt bumpy!)
journey, it has clung on and made periodic appearances in our left Hazcam
images.

This is not the first time a rock has hitched a ride on a Mars rover
mission. Some 18 years ago, a potato-sized rock found its way into the
Spirit rover's rear right wheel, and had to be dislodged. On the Curiosity
rover, the front right wheel has periodically picked up its own traveling
companion. While it's unclear exactly how long these rocks stuck around,
they tended to hop off after a few weeks. Perseverance's current companion
is therefore on its way to setting Mars hitch-hiking records.

https://phys.org/news/2022-06-perseverance-pet.html