First glimpse at ancient asteroid rocks: NASA unveils images of Bennu contents

The extended waiting period is attributed to the fact that scientists only recently managed to penetrate the internal part of the container. High-resolution images are accessible for viewing on the NASA website. The material from Bennu reached Earth on September 24, 2023, after being jettisoned by the OSIRIS-REx probe, about 66,489 miles away from our planet. The capsule made touchdown at the Department of Defense's Utah Test and Training Range, near Salt Lake City, U.S, and after a nitrogen cleanse, was transported to the Lyndon B. Johnson Space Center in Houston, Texas.

In a sterile, custom-designed laboratory, scientists made attempts to pry open the capsule. The problem was that the collector lid became jammed and none of the existing tools could open it. The application of carbon steel tools was disqualified owing to the risk of cosmic material contamination. Consequently, scientists decided to extract around 2.5 ounces of material from the container's casing, right around the stuck lid.

"Our engineers and scientists have been diligently analyzing the 2.5-ounce sample of matter that we managed to gain access to. Simultaneously, they have been strategizing, constructing, and testing new tools that would ensure safe access to the remainder of the material collated from Bennu," explained astrophysicist Dr. Eileen Stansbery, head of the ARES (Astromaterials Research and Exploration Science Directorate) at the Johnson Space Center.

Scientists carefully crafted two new, intricate tools, namely, wrenches made of non-magnetic stainless surgical steel – the only material permitted for utilization inside NASA's sterile glovebox chambers.

"The engineering challenge was to restrict ourselves to materials approved for asteroid sample handling. The new tools also had to operate within the confined space of the glovebox chamber, which limited their size, weight, and reach," explained Dr. Nicole Lunning, a petrologist, geochemist and curator of the OSIRIS-REx mission.

On Friday, January 19, the team fully disassembled the head of the TAGSAM (Touch-and-Go Sample Acquisition Mechanism) sample collection mechanism and snapped pictures of the interior of the collector. Now, researchers are anticipating the dismantling of the container's metal collar. Subsequently, they must put sample trays inside the glove chamber and lay out the material from the container on them. Only once this stage is achieved will it be possible to determine the total mass of rocks from the asteroid. Researchers approximate this weight at a minimum of 8.8 ounces, marking it as the most immense sample of this kind ever to have reached Earth.

Scientists are eagerly awaiting the thorough analysis results of Bennu's stones, gravel, and dust. Spectral analysis at the Reflectance Experiment Laboratory (RELAB) in Rhode Island and examination at London's Natural History Museum revealed that the sample—drawn from the container casing—is surprisingly composed of 5% carbon by weight and carries clay minerals which could only have originated in the presence of water.

"We have hydrated residues rich in organic compounds from the early solar system, exactly what we envisaged when first contemplating this mission nearly 20 years ago," shared Professor Dante Lauretta, an expert in planetary science and cosmochemistry from the University of Arizona and the leader of the OSIRIS-REx project.

However, surprisingly substantial amounts of magnesium, sodium, and phosphorus were also detected in the sample. This discovery alerted the team as scientists never dealt with comparative material before.

While scientists are already examining some of the samples, others will remain untouched to be analyzed with future, yet-to-be-developed instruments. Some Bennu material fragments will be conserved at room temperature, while others will be frozen at minus 80 degrees Celsius. A catalog of samples, which will be accessible to researchers outside the U.S., is projected to be published by NASA in the spring of this year.

Over 200 scientists eager to examine the Bennu material have approached the agency. Any worldwide scientific institution can apply for access to samples stored at the Johnson Space Center in Houston.

The OSIRIS-REx probe was launched towards asteroid Bennu by NASA on September 8, 2016, as a component of the New Frontiers program. The mission's cost—an estimated $1 billion—aimed to supply information that could elucidate the origin of life on Earth. In 2020, the probe was planned to touch the Bennu surface for six seconds, but the contact lasted almost three times longer. On its return on September 24, 2023, OSIRIS-REx projected a capsule harbouring the collected material, about 66,489 miles from Earth. The probe is now en route to asteroid Apophis as part of the ongoing OSIRIS-REx mission, with an estimated arrival date of 2029.

Discovered in 1999, Bennu, an asteroid that flies in proximity to Earth every six years, might in the future collide with our planet. Based on scientific predictions, this could occur in 159 years, specifically on September 24, 2182, with the chance of such an event being 1 in 2700 (0.037%).