Some say it started with a bang, while others argue it was an act of God.
Either way, it’s a question that has perplexed and divided humans for millennia: How did life form on Earth?
On Sunday, when a Japanese spacecraft known as Hayabusa2 returned a sample of space rocks to South Australia, we inched a little closer to finding out.
The rock samples were collected from an asteroid called Ryugu and were dropped off in the SA desert after a 5.2 billion-kilometre journey over the past six years.
And they could be the key to unlocking more about our Earth’s history.
That’s according to Professor Lisa Harvey-Smith, an astronomer at the University of New South Wales and Australia’s Women in STEM Ambassador.
“The samples will help planetary scientists to better understand the composition and motion of materials, such as water, and biological molecules in the solar nebula, which birthed our planet almost 4.6 billion years ago,” she said.
The fragments, collected from the 4.5-billion-year-old asteroid, date back to the earliest stages of the formation of the solar system.
Scientists hope the tiny pieces, likely complex organic molecules, could reveal key information about the origin of life on Earth.
It will be the first sub-surface asteroid sample to return to Earth and may help scientists understand how oceans and life formed here.
How did the samples arrive in South Australia?
In a remarkable use of technology, a capsule carrying the samples was ejected from the Hayabusa2 spacecraft as it flew over South Australia’s outback, to a landing site near Woomera.
Swinburne University’s Professor Alan Duffy, lead scientist of the Royal Institution of Australia, said scientists watched in awe as the “precious cargo of a distant asteroid plunged in a fireball towards the red dirt”.
“After successfully deploying its parachute for the last 10 kilometres, it safely landed and the search team via helicopter quickly identified and recovered the capsule, measuring just 40 centimetres in diameter,” he said.
“The pinch worth of an asteroid inside the capsule may tell us how key ingredients for life on Earth arrived, and whether asteroids like this Ryugu were responsible for bringing it to our planet over the course of four billion years.”
What made this space journey so special?
Meteorites, whose origins are thought to be the same as asteroids, have fallen to Earth before.
However, their structure and volatile substances had been lost on their journey through the atmosphere.
“They will also be contaminated with substances from the Earth,” the Japan Aerospace Exploration Agency (JAXA) said.
“On the other hand, samples from the asteroids are brought back to Earth in the same condition as they were in space, with the ‘re-entry capsule’ protecting the sample through the atmosphere and landing.”
What was Australia’s involvement?
Australia’s national science agency, the CSIRO, has been working alongside JAXA since 2014.
The CSIRO runs two important satellite stations: NASA’s Canberra Deep Space Communication Complex, and the European Space Agency’s New Norcia station.
Thanks to these satellite stations, Hayabusa2 was able to use their navigation, command, control and telemetry services to get to asteroid Ryugu and return home safely.
“We have been working alongside our Japanese partners since the mission launched in 2014,” said Glen Nagle, the outreach and administration lead at Canberra Deep Space Communication Complex, a part of NASA’s Deep Space Network.
“We received the signals when Hayabusa2 made its historic touchdown on asteroid Ryugu in 2019.”
As scientists celebrate the historic development, the mission for Hayabusa2 continues.
The mothership has enough xenon fuel to visit two further asteroids of interest – in 2026 and 2031.