Nasa unveils first sample of 4.5-billion-year-old Bennu asteroid

Space rock gathered in seven-year space mission was delivered to Earth last month

Samples of the Bennu asteroid have been unveiled by Nasa for the first time. Photo: Nasa
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Nasa have offered a first glimpse at samples of a 4.5-billion-year-old asteroid which they believe could hold the key to a greater understanding of the origins of life on Earth.

Initial studies of the space rock derived from Bennu – delivered to Earth last month – show evidence of high-carbon content and water, Nasa said on Wednesday.

Nasa Administrator Bill Nelson said the findings from a seven-year mission in space “will help scientists investigate the origins of life on our own planet for generations to come”.

The Osiris-Rex spacecraft flew close to Earth to drop a capsule carrying 250g of soil from the asteroid on September 25.

Scientists are expected to analyse the celestial discovery for decades to come, helping to unravel the mysteries of how our solar system was formed.

“Our labs were ready for whatever Bennu had in store for us,” said Vanessa Wyche, director of Johnson Space Centre.

“We’ve had scientists and engineers working side-by-side for years to develop specialised gloveboxes and tools to keep the asteroid material pristine and to curate the samples so researchers now and decades from now can study this precious gift from the cosmos.”

Scientists say early forensic investigations of the asteroid have already reaped impressive results.

“The bounty of carbon-rich material and the abundant presence of water-bearing clay minerals are just the tip of the cosmic iceberg,” said Dante Lauretta, Osiris-Rex principal investigator at the University of Arizona.

“These discoveries, made possible through years of dedicated collaboration and cutting-edge science, propel us on a journey to understand not only our celestial neighbourhood but also the potential for life’s beginnings.

“With each revelation from Bennu, we draw closer to unravelling the mysteries of our cosmic heritage.”

The mission team will continue painstaking analysis of the samples for the next two years, with the support of more than 200 scientists from across the globe.

How did the Osiris-Rex secure samples?

Bennu is a near-Earth asteroid that was first discovered in 1999 and is said to be formed from materials that date back billions of years.

The sample collection was a complex process because there was an 18.5-minute delay in sending and receiving signals between mission control and the craft due to the distance.

Navigation cameras on the capsule helped it to successfully reach the asteroid.

Bennu orbits the sun at 101,388kph. Osiris-Rex was programmed to travel towards it at about 19,400kph and slow itself down on approach.

Once close enough, the spacecraft extended its robotic arm and obtained samples.

How did the craft deliver the asteroid soil back to Earth?

After travelling billions of kilometres to Bennu and back, the spacecraft released its sample capsule towards Earth’s atmosphere.

The spacecraft was 102,000km from Earth’s surface at the time – about one-third of the distance from Earth to the Moon.

The capsule entered the atmosphere at 6.42pm while travelling at 27,650km and, within 10 minutes, it landed on a military range in a Utah desert.

Two parachutes that deployed helped to stabilise and slow the capsule down.

Updated: October 12, 2023, 7:01 AM