NASA's Mars Perseverance rover has an "unexpected traveling companion" in the form of a pet rock.

The agency announced at the beginning of the month that "Percy" has carried the object over the past four months.

Over 100 Martian days, or sols, ago – in early February – the rock wiggled onto the rover's front left wheel.

It has been transported more than 5.3 miles across Mars and has made frequent appearances in left Hazcam images.

NASA STEPS UP HUNT FOR EXTRATERRESTRIAL LIFE, WILL COMMISSION 'ABSOLUTELY NECESSARY' STUDY ON UFOS

NASA noted that the rock isn't doing any damage to Perseverance and that this is not the first time a rock has hitched a ride on a Mars rover.

Around 18 years ago, a "potato-sized" rock found its way to the Spirit rover's rear right wheel and had to be dislodged.

NASA's Mars Perseverance rover acquired this image of the area in front of it using its onboard Front Left Hazard Avoidance Camera A. This image was acquired on Feb. 6, 2022 (Sol 343) at the local mean solar time of 14:25:54. (Image Credit: NASA/JPL-Caltech)

Mars Perseverance Sol 413 - Front Left Hazard Avoidance Camera: Perseverance’s pet rock has had some great views of Kodiak, a delta remnant, along its travels. Image taken using the Front Left Haz Avoidance Camera (Hazcam), acquired on April 19, 2022 (Sol 413). (Image Credit: NASA/JPL-Caltech)

On the Curiosity rover, the front right wheel has periodically picked up its own rock.

However, unlike Perseverance's current pet rock, these rocks tend to leave after a few weeks.

NASA: WEBB SPACE TELESCOPE HIT BY MICROMETEOROID

NASA wrote that it is possible the rock could fall out of the left wheel at some point along the future ascent of the crater rim.

"Perseverance’s pet rock has seen a lot on its travels. Back on sol 341, we were still in our Crater Floor Campaign, where we examined rocks that are part of the ‘Máaz’ formation, which we believe is made up of lava flows. If this pet rock could talk, it might tell us about the changes it's noticed as we travelled back north through the Octavia E. Butler landing site, and then west, passing the spectacular remains of the former extent of the delta, 'Kodiak,' on our journey to the western Jezero delta. We’re now in the Delta Front Campaign, and we just abraded what might be our first sedimentary rock," NASA said.

"Perseverance’s pet rock is now a long way from home," the agency added.

CLICK HERE TO GET THE FOX NEWS APP

Perseverance has spent more than 464 sols on Mars and landed in the red planet's Jezero Crater on Feb. 18, 2021.

Rover traversing Mars has 'pet rock': NASA

NASA's Perseverance rover and the rock have traveled more than 5 miles together