Although NASA has enjoyed a string of high-profile successes on the red planet, sometimes Mars throws scientists a curveball. The Perseverance rover came up empty during its first attempt to collect a sample of Martian rock last week, and NASA thinks the rock likely crumbled into rubble and dust rather than remaining in one piece.

Now the rover is trekking southward to its next sample target, where the team plans to try drilling again in early September.

During the first attempt, the multi-step sampling process initially seemed to progress smoothly. The rover bored into the red planet, closed the sample tube with an airtight seal, and safely deposited the tube into a module in the rover's belly on