NASA's OSIRIS-REx spacecraft delivers asteroid Bennu samples to Earth

Asteroid Bennu sample lands at at the Department of Defense's Test and Training Range in Salt Lake City, Utah. (Image source: NASA)

NASA's OSIRIS-REx spacecraft, short for Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer, successfully delivered sample material from asteroid Bennu to Earth on September 24.

The first American mission to collect a sample from an asteroid, OSIRIS-REx released its sample return capsule near the California coast, which later landed at the Department of Defense's Test and Training Range in Salt Lake City, Utah.

What transpired after the asteroid sample landed

Upon the safe landing of the sample capsule in Utah, the OSIRIS-REx team, involved in a number of rehearsals prior, swiftly retrieved it from the ground in Utah to prevent contamination by Earth's environment. Following this, technicians transported the capsule on a cart to a temporary clean room at the Utah base for unwrapping, cleaning, and for disassembly.

The next course of action

The curation team will collect soil and other remnants from the vicinity of the capsule's landing site. The recovery team will transport the capsule by helicopter to the Johnson Space Center in Houston, Texas, where the samples will be kept in a newly-constructed facility - the Astromaterials Research and Exploration Science (ARES) division.

What are the anticipated contents of the sample?

The capsule is expected to have rocks and dust from asteroid Bennu, representing materials from the early stages of our solar system potentially dating back to 4.5 billion years. On October 11, the Johnson Space Centre will host a public unveiling of the asteroid sample.

Johnson Space Center to curate and store majority of samples

According to NASA, the sample will be cataloged and studied until 2025. The majority of the Bennu sample, at least 75 percent, will be carefully preserved at NASA's Johnson Space Flight Center in Houston, ensuring that it remains accessible for scientists globally, for future research, and for future generations of scientists. A smaller portion of the sample will be sent to international partners, the Canadian and Japanese space agencies, for curation. NASA’s Goddard Space Flight Center in Greenbelt, Maryland will provide overall mission management, systems engineering and safety and mission assurance for OSIRIS-REx.

What do scientists learn from the sample?

The pristine material from Bennu presents an opportunity for scientists worldwide to examine and gain insights into the formation of our planet and the solar system roughly 4.5 billion years ago. Additionally, it holds clues to the origins of organic compounds that may have contributed to the origins of life on Earth. Researchers will analyze Bennu's chemical composition, as during its mission at Bennu, the OSIRIS-REx spacecraft detected organic carbon and had interacted with liquid water.

Key milestones from launch to sample return

Launched on September 8, 2016, aboard an Atlas V411 rocket from Kennedy Space Centre in Cape Canaveral, Florida, the OSIRIS-REx spacecraft arrived at asteroid Bennu in 2018. After spending two years orbiting around Bennu, where it mapped and studied the asteroid's rugged terrain, the spacecraft made a significant move on October 20, 2020. On this date, it collected about 250 grams of material from the asteroid. In May 2021, OSIRIS-REx embarked on a return journey covering a staggering distance of 3.86 billion-miles back to Earth. Finally, after two years and four months since leaving Bennu, OSIRIS-REx safely returned to the very place where its journey began. The touchdown marks the end of a seven-year journey to explore asteroid Bennu.

Purpose of OSIRIS-REx's visit to Bennu

According to NASA, scientists can better understand other asteroids and their courses in the universe by studying Bennu. The information gathered by OSIRIS-REx may help improve the future technologies and try to deflect asteroids that threaten to collide with Earth. Every six years or so, Bennu makes its closest approach to Earth. Bennu might approach Earth in the year 2135 more closely than the moon, according to the American space agency.

About Bennu

Bennu, a near-Earth asteroid discovered in 1999, is considered one of the solar system's potentially hazardous objects, according to NASA. It measures approximately 1,720 feet (524 meters) in width, roughly equivalent to the height of the Empire State Building. This asteroid features a dark surface densely populated with boulders and completes its orbit around the sun every 14 months. Scientists at the US space agency believe that Bennu originated from a larger asteroid that collided with another space rock.

Rich in carbon, Bennu is a rubble-pile asteroid, consisting of rocks and dust loosely held together by microgravity. NASA scientists made a remarkable discovery during OSIRIS-REx's sample collection on Bennu's surface. They found that the asteroid was so loosely packed that stepping onto its surface would feel akin to stepping into a child's ball pit.

What happened to OSIRIS-REx after it released the sample?

Around 20 minutes after delivering the Bennu samples, OSIRIS-REx spacecraft started on a new mission to study another near-Earth asteroid called Apophis. Under the new mission name "OSIRIS-APEX" (OSIRIS-Apophis Explorer), the spacecraft will continue its exploration of our solar system. Roughly 1,000 feet wide, Apophis will come within 20,000 miles of Earth in 2029, its closest approach to Earth. Soon after Apophis approaches Earth, OSIRIS-APEX will launch into orbit around Apophis to watch and study how this event has affected the asteroid's orbit, spin rate, and surface properties.