Discovery of Rare Metals in OSIRIS-REx’s Outer Sample Canister: From Rocks and Dust to Bennu, the Birthplace of Life

This bounty of materials comes from the outer surface of OSIRIS-REx’s sample canister. The biggest treasure trove will be revealed in the next few weeks, when mission curators open the canister itself. They have been looking at the rocks and dust in the canister, taking pictures and classifying them. Roughly 1.5 grams have been catalogued thus far, and there is an expectation of more than 250 grams.

NASA broadcasted a public reveal in front of a small audience of reporters, policymakers and students from local school districts on NASA TV and its website this morning. Where did the space rocks come from? What are the origins of the rare metals and do they contain organic Molecules?

The video screen behind him showed a photo of asteroid pebbles and particles that were not in the main sample container. The analysis done by NASA shows that they contain water in hydrated clay minerals, as well as carbon and organic molecule. This carbon is 4.7 percent of the sample by weight. “The carbon and water molecules are exactly the kinds of material that we wanted to find,” Nelson said. In the formation of our own planet they are crucial elements and they will help us determine the origin of life.

Bennu also contains organic material made of compounds incorporating carbon and hydrogen. On Earth, organic compounds are found in living organisms — but also in the absence of life. Organic patches in the Bennu sample are glowing under ultraviolet light. Daniel Glavin, an Antarbiologist at NASA’s Goddard Space Flight Center in Maryland, says that this thing is loaded with organics. “This is incredible material.”

The clay samples from Bennu look pretty small. Water locked inside those clay minerals might be ancient water from the dawn of the Solar System. Asteroids might have carried such water to the early Earth and helped to make it habitable.

The hexagonal crystals are likely sulfur-rich. Sulfur compounds play a crucial role in determining the rate at which rocks melt, as well as being involved in biologically interesting chemical reactions. The iron-rich minerals on the Bennu samples may have helped to catalyse chemical reactions early in the asteroid’s history.

It will take a while for researchers to know how much Bennu they captured. When OSIRIS-REx stretched out its robotic arm in 2020 to collect material from the asteroid’s surface, it came away with so much material that it overflowed the collecting mechanism.

The moon rocks brought back to Earth by astronauts in the 1960s and 1970s will be the most material to come back from outer space. Japan’s two Hayabusa missions, which both flew to asteroids and came back with samples, together brought back a teaspoon of material at most.