‘It’s amazing’: Scientists analyze 4.6 billion-year-old dark dust from asteroid Bennu | Asteroids
A teaspoon of dust and dark grains captured from an asteroid 200 meters from Earth has arrived at the Natural History Museum in London, where scientists are preparing to uncover its secrets.
Researchers at the museum received 100 mg of the original material, which dates back 4.6 billion years to the dawn of the solar system, after NASA’s Osiris-Rex mission stopped at the asteroid Bennu in 2020 and returned samples to Earth in September.
The spacecraft touched down briefly on Bennu, an asteroid that has a 1 in 1,750 chance of colliding with Earth within the next 300 years, and collected more than 60 grams of untouched material, the largest amount brought back from space since the Apollo program.
“It’s amazing. It’s like a little treasure that takes us back to the beginning of the solar system,” said Dr. Ashley King, a planetary scientist who will work on the grains at the museum. “I can’t wait to get my hands on it and see what we can learn about the early solar system.”
Preliminary analyzes by NASA researchers found that the asteroid pieces were rich in carbon and water, with some of the carbon bound to organic compounds. Scientists expect to study the samples for decades as they seek to understand how the solar system formed and whether asteroids delivered large amounts of water to Earth and other planets.
A key area of research will be to analyze hydrogen isotopes in the waters associated with Bennu to see if any of them match those found in Earth’s oceans.
Beyond questions about our cosmic origins, there are more existential matters, such as how to divert or destroy asteroids that pose a potential threat to Earth. At a third of a mile across, Bennu is much smaller than the six-mile-wide asteroid that caused disaster for the dinosaurs, but it would cause massive damage if it struck Earth.
The first two years of research at the Natural History Museum will focus on non-destructive testing, such as X-ray diffraction and electron microscopy to learn about Bennu’s mineral composition and structure. The largest grains in the sample are millimeters across, while the smallest are mere dust particles.
“It doesn’t feel like a lot of material, but it’s a lot to work with,” King said. The museum is home to one of the world’s leading meteorite collections, and the staff are well accustomed to handling small quantities of extremely precious materials from outer space.
Unlike meteorites that collided during their fiery passage through Earth’s atmosphere, dust and rock fragments from Bennu were brought to Earth in a pristine state, allowing scientists to get a rare look at the asteroid unchanged.
Professor Sarah Russell, head of the Planetary Materials Group at UCL, said: “This material, no more than a teaspoon’s worth, will keep us busy for years as we study every minute grain to understand its composition and structure and see what secrets we can uncover.” Natural History Museum.