The sample comes from a hole about 2.5 inches deep drilled on Feb. 8 in a flat plate of sedimentary bedrock that the space agency managers have named "John Klein" in memory of a Mars Science Laboratory deputy project manager who died in 2011.

WSJ: Rover on Mars Extracts First Rock-Core Sample

Curiosity drilled a hole in Mars to collect a sample of its surface, which is the first time any rover has drilled such a hole on the Red Planet.

FORBES: Curiosity Drills A Hole On Mars

So, the command was given to drill a second hole that was deep enough to push some cuttings into the tool's sample acquisition chamber.

BBC: Curiosity Mars rover takes historic drill sample