Asteroid samples to point to Earth origins

The Hayabusa2 spacecraft landed on the asteroid Ryugu in February.
The Hayabusa2 spacecraft landed on the asteroid Ryugu in February.

A fireball is set to light up the sky over the South Australian outback, signalling the return to earth of a Japanese capsule carrying the first sub-surface asteroid samples, which could provide clues to the origins of life on Earth.

The capsule has been travelling onboard the Hayabusa2 spacecraft which first landed on the Ryugu asteroid, more than 300 million kilometres from earth, in February last year.

Its release from the spacecraft is timed for late on Saturday but as it enters the earth's atmosphere the fireball will streak across the sky around 4am on Sunday, about 200 kilometres north of Woomera, in SA's north.

"That's going to be spectacular, so if you happen to live nearby you better wake up early and watch the sky," Professor Masaki Fujimoto, from the Japan Aerospace Exploration Agency said.

The fireball will be brightest as the capsule reaches an altitude of about 40 of 50 kilometres but as it descends to about 10 kilometres a parachute will be deployed and a beacon signal will start, allowing a retrieval team to pinpoint its landing site in the Woomera protected area.

"This is really the grand finale of a 10-year effort, if you count the development time and the six-year cruise of the spacecraft itself," Professor Fujimoto said.

Once retrieved, scientists say its potential significance should not be underestimated.

Asteroids are thought to have formed at the dawn of the solar system and Ryugu may contain organic matter that could have contributed to life on Earth.

Professor Fujimoto said when the Earth was first created it was dry and for life to begin water had to be brought to the planet.

"Something like Ryugu brought water to earth and that's why we are here," he said.

Australian National University space rock expert Trevor Ireland, who is in Woomera, said he expected the Ryugu samples to be similar to the meteorite that fell in Australia near Murchison, Victoria, more than 50 years ago.

"The Murchison meteorite opened a window on the origin of organics on Earth because these rocks were found to contain simple amino acids as well as abundant water," Professor Ireland said.

"We will examine whether Ryugu is a potential source of organic matter and water on Earth when the solar system was forming and whether these still remain intact on the asteroid."

After releasing its precious cargo, Hayabusa2 will begin a second, 10-year mission to rendezvous in July 2031 with a much smaller asteroid known as 1998 KY26.

Astronomer Brad Tucker said advancing technology had allowed space missions to regularly land on objects in space and return back to Earth.

Just this week China successfully landed a spacecraft on the moon's surface with its Chang'e-5 probe to collect two kilograms of lunar material to help scientists learn more about the moon's origins.

The mission visited a previously unexplored area known as Oceanus Procellarum or "Ocean of Storms".

Dr Tucker said such missions were allowing scientists to "get our hands dirty and learn a lot about the solar system and our own planet".

"Future space travel and exploration missions are going to need to be able to extract resources in space," he said.

"Missions like Hayabusa2 are laying the groundwork for this endeavour."

Australian Associated Press