The final samples collected from the asteroid Bennu are finally coming into view. Four months after they were dropped off in a Utah Desert and nine days after safely prying open two stubborn fasteners, a team of astromaterials experts at NASA’s John Space Center has revealed the contents of the fully disassembled OSIRIS-REx sampler.
On January 19, NASA’s planetary science division posted “It’s open! It’s open!” on Twitter/X along with a photograph of dark dust and tiny rocks inside the canister. The reveal comes after the team successfully removed the remaining two fasteners that prevented them from opening the Touch-and-Go-Sample-Acquisition-Mechanism (TAGSAM) head.
The samples were collected in 2020 from a 4.5 billion year-old near-Earth asteroid named Bennu. According to NASA, the remaining sample material contains dust and rocks that are up to about 0.4 inch in size. The team will determine the final mass of the sample over the coming weeks. Previously, the team collected 2.48 ounces of asteroid material, which surpassed their initial goal of bringing at least 2.12 ounces back to Earth.
The Smithsonian’s National Museum of Natural History debuted a piece of the asteroid Bennu to the public for the first time in November 2023. The sample was dropped off on Earth by NASA’s OSIRIS-REx spacecraft on September 24, 2023. After the dropoff, the spacecraft continued on to a new mission called OSIRIS-APEX. It is set to explore the asteroid Apophis when it comes within 20,000 miles of Earth in 2029.
What’s next for the Bennu samples
While it looks like average rocks and dirt to the naked eye, the sample is actually asteroid material that could hold chemical clues to our solar system’s formation. Evidence of essential elements like carbon in the rocks outside of the main sample container have already been uncovered by NASA scientists and these early samples also contain some water-rich minerals. Scientists believe that similar water-containing asteroids bombarded Earth billions of years ago, which provided the water that eventually formed our planet’s first oceans.
The asteroid Bennu dates back to the first 10 million years of the solar system’s development, so it gives scientists a window into what this time period looked like. Bennu is shaped like a spinning top and is roughly one-third of a mile across at its widest part–slightly wider than the Empire State Building is tall. The space rock is classified as “potentially hazardous” by NASA because there is a slim 1 in 2,700 (about 0.037 percent) chance that Bennu could collide Earth by 2182.
The sample curation team at NASA is expected to release a publicly available catalog of the Bennu samples later this year.