Older than the Sun: NASA's spacecraft brought back 'stardust'

Material older than the Sun has been found in asteroid dust collected by NASA from more than 200 million miles away from Earth.

In samples of the Bennu asteroid examined by scientists, "proto-solar grains," or star dust formed billions of years ago around stars that have reached the end of their lifespan, were detected, which are said to be "chemically primitive."

THE UNIVERSE BEFORE THE SUN FORMED

Researchers say these samples offer a unique window into the birth of the Solar System. These particles, much older than any meteorite that ever hit Earth, shed light on the universe before the formation of the Sun.

NASA's OSIRIS-REx spacecraft briefly touched down on Bennu's surface in 2020, collecting a sample of about 120 grams, and the capsule returned to Earth in 2023.

"Our data suggest that Bennu's parent asteroid formed in the outer reaches of the Solar System, likely beyond the orbit of Saturn," said Prof. Jessica Barnes of the University of Arizona.

LOOK AT THE SUNRISE

Chemical analyses have revealed organic matter from outside the Solar System and the interstellar medium, as well as material formed at high temperatures in regions close to the Sun and then drifted outward.

"We are seeing a unique snapshot of the outer Solar System at the time our Sun was born. Some of these grains have survived virtually intact for billions of years and tell us the story of the environment in which the planets were born," said Professor Sara Russell, a planetary scientist at the Natural History Museum in London.

The findings reshape the picture of the formation of the Solar System. Previous studies have also revealed that the building blocks of life were found on Bennu.