Could asteroid dust hold the secret to life on Earth?

Scientists think tiny specks of dust collected from an asteroid from deep space could hold the clue to one of the biggest questions ever asked - how life started on Earth.

Bennu is a relatively small asteroid that passes close to Earth around every six years.

In September 2023 a Nasa spacecraft collected a sample from Bennu, and brought it back to Earth.

Now scientists have carried out a detailed analysis of the space rock specimen, and it's proved to be a treasure trove.

What happened when the Bennu sample was brought back to Earth?

Grabbing a bit of Bennu has been one of the trickiest missions Nasa has ever attempted.

A spacecraft called Osiris Rex used a robotic arm to collect some of the space rock, before packing it into a capsule and returning it to Earth in 2023.

Those bits of Bennu were sent around the world, with a teaspoon-sized portion sent to the UK.

The latest results of a detailed analysis have stunned scientists. They say the grains are tiny, and each one is telling us something new.

Bennu contains thousands of carbon rich compounds, including amino acids and nucleobases, which are the building blocks of DNA.

"It's just incredible how rich it is. It's full of these minerals that we haven't seen before in meteorites, and in a combination of them that we haven't seen before. It's been such an exciting thing to study," said Professor Sara Russell from the Natural History Museum in London.

How can Bennu help scientists understand life on Earth?

Scientists have been analysing these little bits of Bennu

Around 4.5 billion years ago, a swirling cloud of gas and dust came together to form the solar system.

But there was a lot of material left over, after the planets formed, and asteroids like Bennu were everywhere.

This latest studies - published in the journal Nature - adds to growing evidence that they brought water and organic material to Earth to make life possible.

But asteroids were also colliding with other planets elsewhere.

"Earth is unique, in that it's the only place where we have found life so far, but we know asteroids were delivering those ingredients, the carbon and the water, throughout the Solar System," explained Dr Ashley King, from the Natural History Museum.

"And one of the big things that we're trying to understand now is, if you have the right conditions, why do we have life here on Earth - and could we potentially find it elsewhere in our Solar System?"