In the movie Alone in the world, Tom Hanks, abandoned on an island, had the Wilson ball. In Wall-e, the robot had a cockroach. Well, the Perseverance rover on Mars has a rock. A friendship solid as a rock, according to Nasa.
“You don’t choose your pebble, the pebble chooses you. This is how NASA explains this curious relationship. “For four months, Perseverance has had an unexpected companion” who nestled in the rover’s left front wheel.
Nestled in one of the rover’s six wheels
If Perseverance left Earth on July 30, 2020, it only landed on Mars on February 18, 2021, in the Jezero crater. Its role is to collect samples of the Martian soil, in particular “carrots” (a cylindrical sample, cut out of the ground by a special drilling tool called a corer). Perseverance collects and stores them. Then deposits them in sites indicated by NASA to, one day, be recovered in order to bring them back to Earth to be analyzed.
Like all rovers, Perseverance regularly takes pictures of it from all angles, allowing teams on Earth to ascertain its condition. But quickly, a rock “decided to get on board clandestinely to enjoy the trip” in one of the 6 titanium and aluminum wheels of the rover. Each is 52.5cm in diameter. Suddenly the rock is the size of a very large potato.
Since then, they have traveled 8.5km together. “The pebble does no damage. And he hangs on! We see it regularly in our images. »
A novel of friendship soon put to the test
Scientists have a soft spot for this little stowaway, even if officially they haven’t given it a name (yet). Moreover, the one they call “pet rock” (the “pet rock”, like pets) breaks records for duration and distance in pairs with a rover.
“If this rock could talk, it would have told us about the ground changes since we’ve been heading north!” “, marvel the teams of the mission.
However NASA tries not to get too attached to him, because he could leave Perseverance soon: the rover will go up the slopes of a crater, and the tilt could mean the end of this romance. Despite everything, scientists are almost amused by its future. “A geologist in the future might be surprised to find this rock far from its original environment and even research it, who knows? »
In any case, Perseverance, since its arrival, is not alone on Mars.