The Perseverance Rover has finished exploring the C-TOT terrain and is retracing its path before heading on to the Delta. It reached the site of a key mission milestone, the first rock grind, and then messed it up a bit on the episode of Mars Guy. This story starts just over seven months ago when Perseverance first entered C-TOT, Navajo for amongst the sand. It was there to sample the oldest rocks in Jezero Crater. Here's a model of the Rover and Mars Guy for scale in the approximate location where at first tried out its abrading bit. This is the robotic arm with the tools and instruments used to investigate rocks. Here's a rock hammer for scale and to represent the capability of the abrading bit to expose fresh rock surfaces. The drill uses a combination of rotary and percussion motions, so it's a hammer drill like this example. The hammering motion is very effective on concrete and rocks. Here's a view of the arm with the drill deployed on a rock slab. Up to this point in the mission, the abrading bit had not been used. Turns out that this rock was softer than expected from weathering and the bit went in about 25mm, about an inch. When it was done, the drill chuck released the bit and left it in the rock. This looks like it got stuck and had to be abandoned, but this was the plan from the beginning. The engineers call it the launch abrading bit because it was designed as a functional cover for the drill chuck during the Rover's launch and landing. The other drill bits, including two abrading bits, could be sterilized and stored in the bit carousel. The launch abrading bit was also sterilized, but would not have the same protection from contamination as the bits inside. The empty drill chuck was loaded up with another abrading bit from the bit carousel, this one with a bit exchange tangs that allowed it to be swapped in and out. Then Perseverance stowed its arm and drove a short distance to another rock slab where it did another grind and its first coring operation. It will last 6 months and will pick up on the Rover's latest drive activity that brought it back to the drop to braiding bit. As I presented in episode 44, Perseverance has been breaking distance records. On saw 351, it smashed its previous record by 73m driving 314m, almost 3.5 football fields in length. But it was during the next drive that it seemed to swerve toward the side of the abrading bit. It's safe to assume that its autonomous driving system was just dodging some large rocks, but it's also fun to imagine something a bit more malicious. Here's the view looking back at the first grind site. Masscam C got this shot, which shows the bit out of its hole and on its side pointing in the drive direction. You can see the Rover tracks on either side, so it looks like it drove right over the bit, just clipping it with one of its right wheels. This documented incident of the first hit and run on Mars should make this bit a highly valuable artifact for some future collector.