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.

A capsule carrying about a half cup of dust and rocks from an ancient asteroid named Bennu landed in the Utah desert in 2023. The samples were collected by NASA’s OSIRIS-REx mission, which sent a probe to rendezvous with Bennu in outer space.