Rock and dust samples retrieved by NASA from the asteroid Bennu exhibit some of the chemical building blocks of life, according to research that provides some of the best evidence to date that such space rocks may have seeded early Earth with the raw ingredients that fostered the emergence of living organisms.

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.The findings provide the strongest evidence yet that asteroids may have planted the seeds of life on Earth and that these ingredients were mingling with water almost right from the start.