Osiris-rex bennu asteroid

NASA's OSIRIS-REx mission successfully collected samples from asteroid Bennu in 2020, returning to Earth with primordial Solar System material.

About this subject

NASA's OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) spacecraft launched on September 8, 2016, with the goal of studying the asteroid Bennu and returning samples of its surface to Earth. Bennu is a carbonaceous (C-type) asteroid about 500 meters in diameter, classified as a near-Earth object (NEO). Its orbit crosses Earth's every six years, and there is a small chance (1 in 2,700) of an impact in the late 22nd century, making its study crucial for planetary defense strategies.

The mission reached Bennu in December 2018, and after detailed mapping, conducted sample collection on October 20, 2020. The TAGSAM (Touch-And-Go Sample Acquisition Mechanism) arm touched the surface for just a few seconds, firing nitrogen gas to lift dust and pebbles. The collected amount exceeded expectations, with over 250 grams of material, five times the minimum planned. The return capsule landed in the Utah desert on September 24, 2023, and was transported to NASA's Johnson Space Center for analysis.

Bennu's samples are considered time capsules from the early Solar System, over 4.5 billion years ago. Carbonaceous asteroids like Bennu are believed to contain organic compounds and water, essential ingredients for life on Earth. Initial results indicate the presence of carbon and hydrated minerals, reinforcing theories that asteroids may have seeded the building blocks of life on our planet. Detailed analysis will continue for decades, involving scientists worldwide.

Beyond science, OSIRIS-REx demonstrated techniques for rendezvous and sampling of small bodies, essential for future asteroid mining missions or trajectory deflection. The spacecraft, renamed OSIRIS-APEX, is now heading to the asteroid Apophis, which will make a historic close approach to Earth in 2029. Thus, the legacy of OSIRIS-REx extends beyond Bennu, helping humanity better understand the hazards and resources of near space.

Frequently Asked Questions

Why was asteroid Bennu chosen for the OSIRIS-REx mission?

Bennu was selected because it is a carbonaceous asteroid rich in carbon and near Earth, with potential to contain primordial organic compounds. Its well-known orbit and suitable size facilitate rendezvous and sample collection.

What is the scientific importance of Bennu's samples?

The samples can help understand the formation of the Solar System, the origin of organic compounds and water on Earth, and provide insights into the composition of asteroids that could impact our planet.

What happened to the OSIRIS-REx spacecraft after delivering the samples?

After releasing the sample capsule, the spacecraft was renamed OSIRIS-APEX and began a new mission to study the asteroid Apophis, which will make an extremely close approach to Earth in 2029.