The latter is made up of six different instrument stations that gather data on plate tectonics, hydrothermal vents and deep sea creatures.

MSN: Seafloor observatory to keep close eye on Arctic Ocean

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

As he filled his plate, the cautious grin disappeared into the deep furrows of a beaming smile.

NEWYORKER: Luda and Milena

The grooves are only a few thousand atoms deep and must be uniform across an entire 15-centimeter plate.

FORBES: Trick Of The Light

The grooves are only a few thousand atoms deep and must be uniform across an entire 6-inch plate.

FORBES: Trick of the Light

Between them they keep alive a tradition that goes back centuries, a tradition celebrated on the plate in the form of stuffed mussels, marinated anchovies, octopus salad, deep-fried sea anemones, prawns with cannellini beans, and linguine with spiny lobster.

BBC: Sardinia, land and sea

Given all the discoveries that we have made from an up-close investigation of these ocean ridges, we can't help but wonder what we might find at the far end of the same plate tectonic cycle where seafloor is drawn back into the Earth's interior at deep-ocean trenches.

CNN: Probing the ocean's undiscovered depths