Osiris-rex bennu asteroid

NASA's OSIRIS-REx mission collected samples from asteroid Bennu, a carbon-rich celestial body that may hold clues about the origin of life on Earth.

About this subject

Asteroid Bennu, classified as a near-Earth object (NEO) of carbonaceous type, measures about 500 meters in diameter and orbits the Sun every 1.2 years. Its primitive composition, rich in carbon and organic compounds, makes it a high-value scientific target for understanding the building blocks of the early solar system. NASA's OSIRIS-REx mission (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) was launched in September 2016 and took two years to reach the asteroid. In December 2018, the spacecraft entered orbit around Bennu, conducting a detailed surface mapping to select the collection site.

The sample collection maneuver occurred in October 2020, when the robotic arm TAGSAM (Touch-And-Go Sample Acquisition Mechanism) touched the surface for a few seconds and released nitrogen gas to lift regolith. The spacecraft successfully captured about 250 grams of material, well above the planned 60 grams. After collection, OSIRIS-REx began its return journey to Earth, arriving in September 2023 with the sample capsule landing in the Utah desert. The material is being analyzed by institutions worldwide, with preliminary results indicating the presence of water and organic compounds.

Bennu is also classified as a potentially hazardous asteroid (PHA) due to its orbit crossing Earth's. Trajectory studies indicate a small chance of impact in the 22nd century, making the mission crucial not only for science but also for developing planetary defense strategies. Additionally, OSIRIS-REx marked the first asteroid sample return to Earth since Japan's Hayabusa2 mission, which collected material from Ryugu. Comparative analysis between Bennu and Ryugu promises to reveal differences in the evolution of carbonaceous asteroids.

Frequently Asked Questions

Why did NASA choose asteroid Bennu for the OSIRIS-REx mission?

Bennu was selected because it is a primitive carbonaceous asteroid rich in organic compounds and water, potentially containing precursor molecules for life. Its near-Earth orbit facilitates the mission, and it is classified as potentially hazardous, providing data for planetary defense.

What is the importance of the Bennu sample?

The sample of regolith and rocks from Bennu allows the study of materials unchanged since the solar system's formation 4.5 billion years ago. Analysis may reveal how organic compounds and water arrived on Earth, contributing to theories on the origin of life.

Has the OSIRIS-REx mission already returned the sample to Earth?

Yes, the sample capsule landed in September 2023 in the Utah desert, USA. The material is currently being distributed to laboratories worldwide for detailed study.