NASA’s OSIRIS-REx spacecraft has left the asteroid Bennu and is on its way back to Earth. 

The robot was able to make contact with the asteroid last year, skimming its surface to collect valuable rubble.

With its payload now securely tucked inside, OSIRIS-REx has fired its engines and begun the 2.3 billion kilometre, two-year trip back to Earth. 

On April 9, 2021, NASA's Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft took one last look at Bennu, the asteroid from which it scooped up a sample last October. 

The mission is on track to deliver a sample of pristine material left over from the formation of our solar system into the hands of researchers.

For two years, OSIRIS-REx studied the asteroid, revealing the many secrets of this ancient body and delivering clues about its rubble-pile-like consistency and surface terrain, which turned out to be much rockier and more rugged than initially expected from the observations of ground-based telescope.

Scientists believe OSIRIS-REx was able to scoop up between 200 and 400 grams of a mix of loose, unconsolidated rock, glass and minerals known as regolith.

On Sept. 24, 2023, the spacecraft will jettison the sealed capsule containing the sample and send it onto a trajectory to touch down in the Utah desert.

More information on the mission is accessible here.