Scientists in Japan said on 15 December they were left "speechless" when they saw how much asteroid dust was inside a capsule delivered by the Hayabusa-2 space probe in an unprecedented mission.
The Japanese probe collected surface dust and pristine material last year from the asteroid Ryugu, around 300 million kilometres (200 million miles) away, during two daring phases of its six-year mission.
This month it dropped off a capsule containing the samples, which created a fireball as it entered the Earth's atmosphere, and landed in the Australian desert before being transported to Japan.
Scientists at the Japanese space agency JAXA on Tuesday removed the screws to the capsule's inner container, having already found a small amount of asteroid dust in the outer shell, an AFP report said.
"When we actually opened it, I was speechless. It was more than we expected and there was so much that I was truly impressed," said JAXA scientist Hirotaka Sawada. "It wasn't fine particles like powder, but there were plenty of samples that measured several millimetres across."
Scientists hope the material will shed light on the formation of the universe and perhaps offer clues about how life began on Earth. They have not yet revealed if the material inside is equal to, or perhaps even more, than the 0.1 grams they had said they hoped to discover.
Seiichiro Watanabe, a Hayabusa project scientist and professor at Nagoya University, said he was nonetheless thrilled. "There are a lot (of samples) and it seems they contain plenty of organic matter," he said. "So I hope we can find out many things about how organic substances have developed on the parent body of Ryugu."
Half of Hayabusa-2's samples will be shared between JAXA, US space agency Nasa and other international organisations. The rest will be stored for future studies as advances are made in analytic technology. But work is not over for the probe, which will now begin an extended mission targeting two new asteroids.
Earlier this year in October, Nasa's OSIRIS-REx spacecraft had also successfully collected samples from asteroid Bennu, which is more than 200 million miles (321 million kilometers) from Earth. The spacecraft, which was launched in September 2016, grabbed dust and rocks from a sample site on Bennu called Nightingale. It is expected to return them to Earth by 2023, after beginning its return journey in March 2021, when Bennu and Earth will be in proper alignment in their orbits.
Apart from revealing further information on how the Solar System was formed, the samples from Bennu will be crucial to better understand asteroids that could impact Earth in the future. According to Nasa, Bennu is a potentially hazardous asteroid that could one day threaten the planet.