‘It blew us away’: how an asteroid may have delivered the vital ingredients for life on Earth

Extraterrestrial rocks, recently delivered by a space probe, could answer the big questions about alien lifeforms and human existence

Several billion years ago, at the dawn of the solar system, a wet, salty world circled our sun. Then it collided, catastrophically, with another object and shattered into pieces.

One of these lumps became the asteroid Bennu whose minerals, recently returned to Earth by the US robot space probe OSIRIS-REx, have now been found to contain rich levels of complex chemicals that are critical for the existence of life.