In a triumph for NASA’s first asteroid sample return mission, new findings suggest that tiny bits of rock retrieved from the asteroid Bennu hold lingering traces of ancient salt water. The discovery hints that life-friendly chemistry could be far more common in space than astronomers previously thought.

Asteroid samples fetched by NASA hold not only the pristine building blocks for life but also the salty remains of an ancient water world, scientists reported Wednesday.

Scientists poring over a sample brought back from the asteroid Bennu have detected amino acids and complex mineral compounds, some of which have never been found in space rocks. A team at the Smithsonian’s National Museum of Natural History discovered a salty residue left over from an ancient brine.