Osiris-rex bennu asteroid

NASA's OSIRIS-REx mission collected samples from asteroid Bennu, bringing back fragments of the early Solar System to Earth.

About this subject

The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) spacecraft was launched on September 8, 2016, to study the near-Earth asteroid Bennu and collect a sample from its surface. Bennu is a carbonaceous B-type asteroid, rich in carbon, with an average diameter of about 490 meters. It orbits close to Earth and is classified as a potentially hazardous asteroid due to its trajectory that could approach our planet in the next century.

The spacecraft arrived at Bennu on December 3, 2018, after a two-year journey. Over nearly two years, OSIRIS-REx thoroughly mapped the asteroid's surface, revealing a world covered in boulders and loose regolith. On October 20, 2020, the mission performed the Touch-And-Go (TAG) maneuver at the site nicknamed Nightingale, using a robotic arm to capture approximately 60 grams of dust and rock fragments.

The sample was sealed and returned to Earth on September 24, 2023, landing in the Utah desert. Scientists hope these materials contain organic molecules and hydrated minerals, providing clues about the formation of the solar system and the origin of life on Earth. Bennu is also studied for its composition, which may contain water trapped in clays, a resource valuable for future space missions.

OSIRIS-REx collected detailed surface data including spectroscopy and high-resolution imagery, helping to select the safest and most productive collection site. The mission also demonstrated autonomous navigation and maneuvering technologies in low-gravity environments, contributing to future asteroid exploration missions.

Frequently Asked Questions

How big is asteroid Bennu?

Bennu is about 490 meters in diameter, roughly 1.5 times the height of the Empire State Building. Its shape resembles an irregular spinning top or a walnut.

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

Bennu is a carbonaceous asteroid rich in organic molecules and hydrated minerals, remnants from the early Solar System. Its near-Earth orbit also makes it accessible and provides data on potentially hazardous asteroids.

How long did it take for the Bennu sample to return to Earth?

The sample was collected in October 2020 and returned to Earth in September 2023, a total of about three years from collection to landing. The return journey lasted approximately 2.5 years.