Sept. 8, 2016: OSIRIS-REx launches

A monochrome, close-up photograph shows a diamond-shaped asteroid with a rough, gravel-like surface centered against a solid black background. Bright, direct lighting highlights thousands of tiny, reflective grey and white specks interspersed with dark, pitted shadows and scattered boulders. High contrast emphasizes its jagged, rounded perimeter and uneven, rubble-covered terrain.

Asteroid Bennu was selected for NASA’s OSIRIS-REx sample-return misison in part because it was believed to be rich in the materials needed for life. Credit: NASA

On Sept. 8, 2016, the Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer (OSIRIS-REx) mission launched from Cape Canaveral, setting off on its 4.4-billion-mile (2 billion kilometers) journey to asteroid Bennu. About the size of an SUV, the OSIRIS-REx spacecraft carries several cameras, an altimeter used to create maps of Bennu, and an arm that would be used to retrieve Bennu’s rock and dust. Scientists hoped that the sample-return mission, the U.S.’s first to an asteroid, would provide clues to the origin of life on our planet – the presence of life-supporting elements would suggest that the ingredients for life were widespread in the early universe.

OSIRIS-REx reached Bennu on Dec. 3, 2018, collected its sample on Oct. 20, 2020, and on Sept. 24, 2023, delivered a capsule holding the sample to Earth. Analysis is ongoing, but has found materials necessary for life. After its Bennu sample transport was complete, the OSIRIS-REx spacecraft (now renamed OSIRIS-APEX) set off on a new mission, this time heading for asteroid Apophis. It is expected to arrive in 2029.

Elisa Neckar is senior production editor of Astronomy magazine, and the editor of the Today in the History of Astronomy feature on Astronomy.com.