The building blocks of life are rich in the asteroid sample ferried to Earth

The NASA Exposure to the Discovery of Black Asteroid Dust and Biologically Endangered Materials from the Inner Canister of OSIRIS-REx

This bounty of materials comes from the outer surface of OSIRIS-REx’s sample canister. Sometime in the next couple of weeks, mission curators will open the canister and reveal the biggest treasure trove. In the meantime, they have been carefully picking their way through the material coating the outside of the canister, photographing and classifying the rocks and dust. Only 1.5 grams have been formally catalogued so far, of an anticipated 250-plus grams brought back by OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification and Security – Regolith Explorer).

This morning, NASA held a public reveal in front of a small group of people, including students from local school districts, and streamed it live on the agency’s website. Determining the scientific story of those space rocks—where did Bennu come from? Does it contain organic molecules or rare metals, and what’s their origin?—could now begin.

Researchers immediately saw black asteroid dust and small particles after the canister was opened. Scientists are excited about the results from those that were sent for analysis.

NASA has shared its first glimpse of the black rocks and dust brought back from an asteroid, but the bulk of the material remains locked inside a sample collection device that researchers need to slowly disassemble.

“We’re already thrilled with the results,” says Dante Lauretta, the principal investigator for NASA’s OSIRIS-REx mission, which sent a spacecraft on a seven-year mission to Bennu and back.

In 2020, the spacecraft briefly tagged the surface of the asteroid, over 200 million miles from Earth, nabbing some rocks in a device called the Touch-and-Go Sample Acquisition Mechanism, or TAGSAM.

Workers rushed the canister to a special lab set up at NASA’s Johnson Space Center. There, workers opened it up inside of special cabinets, so the pristine asteroid samples wouldn’t get contaminated with Earth stuff.

When the researchers removed the TAGSAM collection device from a locking mechanism that held it in place, they saw more dust and larger rocks, a centimeter or so across, that had escaped through a Mylar flap.

All of those rocks have to be painstakingly documented and collected by curators in the astromaterials lab. Lauretta was completely fascinated by one image showing the bounty.

He was in Houston to unveil pictures of the asteroid sample and the first scientific findings, and had spent the weekend staring at the image.

An Asteroid in Bennu, an Unseen, Salty and Peculiar Preserved Monument to the Early Universe

The texture in Bennu is salt-and-pepper, with bright grains and dark grains. “In fact, as I was zooming around these images I felt like I was miniaturized and running around on a tiny little Bennu.”

Most of the rocks nabbed from Bennu are still unseen, however, because they’re locked inside the TAGSAM device, which researchers have to take apart methodically. Even though they think they got 8 ounces, the research team is still not certain how much of the asteroid they brought home.

“It looks fragile, friable, so it’s delicate, possibly,” says Lauretta. You can’t have a favorite child, so all of them look good, but I want to understand what’s going on.

Bennu also has materials made of compounds with carbon and hydrogen. In the absence of life, organic compounds are found in living organisms. The organic patches in Bennu look like a holiday tree. Glavin is an Astrobiologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This is incredible material.”

The clay samples from Bennu appear to be very small. Water locked inside those clay minerals might be ancient water from the dawn of the Solar System. It is possible that asteroids carried the water to the early Earth.

There are likely hexagonal crystals that are 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 Bennu samples also contain iron-rich minerals with large flat surfaces, which might have helped catalyse chemical reactions early in the asteroid’s history.

Since the Apollo astronauts brought Moon rocks to Earth in the 1960’s and 70’s, it will be the most material to come back from outer space. Two Hayabusa missions flew to asteroids and returned with samples, but they didn’t bring much material back.