A recovery team in Australia has found a space capsule carrying the first significant quantities of rock from an asteroid.
The capsule, containing material from a space rock called Ryugu, parachuted down near Woomera in South Australia.
The samples were originally collected by a Japanese spacecraft called Hayabusa-2, which spent more than a year investigating the object.
The container detached from Hayabusa-2, later entering the Earth’s atmosphere.
“Hayabusa-2 is home,” Dr Yuichi Tsuda, project manager for the mission, told journalists on Sunday morning (GMT).
“We collected the treasure,” he said, adding: “Everything was perfect.”
He added that there was no damage to the container.
Earlier on Saturday, the capsule was picked up by cameras as a dazzling fireball streaking over Australia’s Coober Pedy region.
Screaming towards Earth at 11km/s, it deployed parachutes to slow its descent. The capsule then began transmitting a beacon with information about its position.
The spacecraft touched down on the vast Woomera range, operated by the Royal Australian Air Force.
At around 18:07 GMT, the recovering team identified where the capsule had landed. A helicopter, equipped with an antenna to pick up the beacon, took to the air shortly afterwards to hunt for the container.
The capsule was then taken to a “quick-look facility” for inspection before being airlifted to Japan.
There, scientists plan to collect gases from inside the container for analysis.
The 16kg capsule will then be transported to a curation chamber at the Japan Aerospace Exploration Agency (Jaxa) in Sagamihara for analysis and storage.
The mission planned to collect a sample of more than 100mg from the asteroid Ryugu.
Prof Alan Fitzsimmons, from Queen’s University Belfast, said the sample would “reveal a huge amount, not only about the history of the Solar System, but about these particular objects as well”.
Asteroids are essentially leftover building materials from the formation of the Solar System. They’re made of the same stuff that went into forming the Earth, but they avoided being incorporated into planets.
“Having samples from an asteroid like Ryugu will be really exciting for our field. We think Ryugu is made up of super-ancient rocks that will tell us how the Solar System formed,” Prof Sara Russell, leader of the planetary materials group at London’s Natural History Museum, told BBC News.
Studying the samples grabbed from Ryugu could tell us how water and the ingredients for life were delivered to the early Earth.
It had long been thought that comets delivered much of the Earth’s water in the early days of the Solar System. Alan Fitzsimmons said the chemical profile of water in comets was sometimes different from the profile of water in our planet’s oceans.
The water composition of some asteroids in the outer Solar System, however, is a much closer match. Ryugu probably originated in this cold zone, before migrating inwards to its current orbit, closer to Earth.
“It may be that we’ve been looking to comets all this time for delivering water to Earth in the early Solar System. Perhaps we should have been looking a bit closer to home, at these primitive but rather rocky asteroids,” Prof Fitzsimmons told BBC News.
“Indeed that’s something that will be looked at very carefully in these Ryugu samples.”
The Hayabusa-2 spacecraft, which bypassed the Earth after releasing its capsule, is being sent on another mission. It will now travel to a much smaller, 30m-wide asteroid in 2031.