From Outer Space: Why are the asteroid samples collected by NASA's OSIRIS-REx mission important

NASA has successfully concluded its first sample return expedition from an asteroid late last night. A scientific capsule, carrying materials from an asteroid landing, completed a remarkable 1.2 billion-mile voyage originating from the asteroid Bennu.

This capsule was released from the OSIRIS-REx spacecraft during its Earth flyby last night, which then reentered Earth’s atmosphere at a velocity of approximately 27,000 miles per hour.

Data that could be more valuable than gold
The OSIRIS-REx mission, which took flight in 2016, has amassed a significant quantity of asteroid material, totalling several hundred grams. This invaluable haul holds the promise of unravelling the mysteries surrounding the initial phases of our solar system’s formation.

During a mission overview briefing, Melissa Morris, the OSIRIS-REx programme executive, expressed, “NASA’s commitment to missions like OSIRIS-REx underscores our commitment to exploring the abundant asteroid population within our solar system. These celestial bodies hold the key to understanding the genesis and evolution of our solar system – our very own cosmic origin story.”

Recovery teams successfully retrieved the sample from the Utah desert, and at 12:15 PM ET, a helicopter departed with the precious cargo. The next step involves transporting the capsule to a provisional clean room, where an initial disassembly procedure will commence.

During this process, larger components like the backshell will be removed. Subsequently, a crucial nitrogen purge operation will be carried out. In this phase, nitrogen will be introduced into the canister to safeguard the sample, preventing any contamination from Earth’s atmosphere.

Following this safeguarding step, the canister will be transported to the Johnson Space Center in Houston, Texas. Upon arrival, it will be opened for the very first time, enabling scientists to conduct a thorough analysis of the enclosed sample.

Studying the possible origin of life
The OSIRIS-REx mission represents NASA’s maiden endeavour in retrieving a sample from an asteroid, marking a significant milestone. Notably, it takes inspiration from Japan’s space agency, JAXA, which achieved this feat in its groundbreaking Hayabusa and Hayabusa 2 missions. While the initial Hayabusa mission managed to procure only a minuscule quantity of material, the subsequent Hayabusa 2 mission triumphantly returned approximately five grams of asteroid material from Ryugu in 2020.

In contrast, OSIRIS-REx has brought back a considerably larger amount of material from asteroid Bennu, totalling around 250 grams. This substantial haul opens up new horizons for scientific exploration, particularly when investigating minute trace elements. Nevertheless, researchers view these two missions as complementary rather than competitive, recognizing the unique contributions each makes to advancing our understanding of asteroids and the cosmos.

Lauretta, a member of the Hayabusa 2 team, emphasized the diversity among asteroids, stating, “Not all asteroids are the same.” Despite both Ryugu and Bennu sharing a similar spinning-top-like shape, they exhibit distinct characteristics.

Ryugu, for instance, is larger and possesses a reddish hue, while Bennu is smaller and appears more blue. The significance of this colour contrast remains a mystery, but the analysis and comparison of the samples here on Earth promise to shed light on both the similarities and distinctions between these celestial bodies.

As Lauretta aptly put it, this collaborative effort is seen as a single, extensive sample analysis program, uniting researchers worldwide in a common quest for knowledge.

Asteroids: Flying time capsules
When scientists seek to unravel the mysteries of Earth’s formation, they extend their gaze beyond our planet into the broader solar system. It is well-established that star systems originate from vast clouds of gas that collapse into a central star, subsequently forming a disk of material around it.

This is evident not only in other star systems but also within our own solar system, where the planets orbit the sun in a shared direction and within a single plane. This alignment supports the notion that they emerged from a solitary disk of material.

A portion of this material coalesced to create planets, while the rest found its way into the earliest asteroids, some of which still endure to this day.

Bennu, the asteroid from which OSIRIS-REx acquired its sample, is believed to consist of material dating back around 4.5 billion years, potentially serving as a time capsule preserving the earliest stages of the solar system. However, definitive confirmation of its age awaits a comprehensive and meticulous analysis.