Discovery of the ferried rock and dust from an asteroid 100 million miles away in the Utah desert with OSIRIS-REx
At long last, NASA’s curation scientists have revealed what OSIRIS-REx ferried back from an asteroid 100 million miles away. The seven-year mission scooped up a rock sample from Bennu in 2020, then returned it to Earth in September, parachuting it down into the Utah desert. They cleaned and shipped the capsule to Johnson Space Center in Houston, Texas, so that there was no sign of harmful organisms in the rocks, and they are now analyzing the cargo.
At least one of the rocks in the Bennu sample is crumbly and hummocky-looking, similar to the boulders that dominate Bennu’s rubbly surface. The mission’s principal investigator, Dante Lauretta at the University of Arizona in Tucson, calls it his “favourite grain” so far. There are also examples of both dark-coloured and light-coloured rocks, as scientists had suspected might be on Bennu. The areas altered by water early on could be represented by the light colors.
As the audience cheered, the video screen behind him showed a photo of dark, coal-colored asteroid pebbles and particles within the canister, but outside the main sample container. NASA’s first analysis shows that they contain water in hydrated clay minerals, as well as carbon and organic molecules, he said. The sample has a carbon content of just over 4% by weight. “The carbon and water molecules are exactly the kinds of material that we wanted to find,” Nelson said. “They are crucial elements in the formation of our own planet and they are going to help us determine the origins that helped lead to life.”
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 lab at the Johnson Space Center. The asteroid samples were opened up inside of special cabinets to prevent them from being 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.
The Astromaterials lab has to carefully collect and record all of the rocks. Lauretta was enamored by one image of the bounty.
“I have been looking at this image for days, and I am more interested in the day now than I ever have been,” he said at the event held in Houston.
Bennu, the most beautiful baby Earth has seen in 200 years: Discovery of organics on Earth from asteroid surface samples with OSIRIS–REx
“Bennu has a salt andpepper kind of texture, bright grains and dark grains, and we are seeing that,” says Lauretta. “In fact, as I was zooming around these images I felt like I was miniaturized and running around on a tiny little Bennu.”
It will be a few weeks before researchers have an idea of 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.
“It looks fragile, friable, so it’s delicate, possibly,” says Lauretta. All of them look gorgeous but I want to understand what’s going on with that child.
Bennu has organic material made of compounds with carbon and hydrogen. On Earth, organic compounds are found in living organisms — but also in the absence of life. Under ultraviolet light, organic patches in the Bennu samples light up like a holiday tree. “This thing’s loaded with organics,” says Daniel Glavin, an astrobiologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. This is amazing material.
The clay samples from Bennu look like tiny fibres in electron microscopy images. Water locked inside those clay minerals might be ancient water from the dawn of the Solar System. Water carried by asteroids may have made the early Earth hospitable.
There are hexagonal crystals that are likely sulfur-rich. Sulfur compounds are involved in many biologically interesting chemical reactions and play a key role in determining the rate at which rocks melt. 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.
It will be the most material to arrive on Earth from outer space since the Apollo astronauts brought lunar rocks back in the 1960s and 1970s. Japan’s two Hayabusa missions, which both flew to asteroids and came back with samples, together brought back a teaspoon of material at most.