The building blocks of DNA have been found in samples returned to Earth from an asteroid, suggesting life rained down from space and could have formed elsewhere.

There’s certainly nothing living on the asteroid Bennu, an airless, 1,614-ft. rubble pile orbiting the sun about 40.2 million miles from Earth. But that doesn’t mean that Bennu hasn’t all at once become one of the most biologically interesting objects in the solar system.