A Japanese spacecraft is about to send a 'treasure box' of asteroid dust plummeting to Earth. Watch the sample return live.

• Japan's Hayabusa-2 spacecraft is set to deliver a sample of rock and dust from asteroid Ryugu to Earth on Saturday.
• Hayabusa-2 blasted the asteroid with a bullet in 2019. The "treasure box" it's bringing back holds the world's first sample from below the surface of an asteroid.
• Studying this space rock can reveal new information about the evolution of the solar system and the origins of life on Earth.
• Watch live coverage of the return below starting at 12 p.m. ET on Saturday.
• Visit Business Insider's homepage for more stories.

A Japanese spacecraft is set to return from its asteroid-blasting mission on Saturday. In a dramatic finale, the Hayabusa-2 spacecraft is expected to send at least 100 milligrams of alien space rock plummeting into the Australian outback.

The sample comes from asteroid Ryugu: a primitive, half-mile-wide rock that zips through our solar system up to 131 million miles (211 million kilometers) from the sun. The Japan Aerospace Exploration Agency (JAXA) launched Hayabusa-2 in 2014 with the goal of collecting the first sample of material from below an asteroid's surface.

The spacecraft first landed on Ryugu in February to collect shallow samples from the surface. But scientists knew that probing deeper could reveal more pure rock from the beginnings of our solar system, since that material hasn't been exposed to harsh radiation from the sun.

So in April 2019, Hayabusa-2 blasted a 33-foot crater into the asteroid using a copper plate and a box of explosives. That loosened rocks and exposed material below the surface. Three months later, in July 2019, the probe lowered itself to Ryugu once again and scooped up the debris.

Now, the probe has almost completed the 5.5-million-mile (9-million-kilometer) journey home.

Sometime between 12 p.m. and 1 p.m. ET on Saturday, the spacecraft will shoot a capsule containing the samples toward Earth.

A bright fireball will streak across the sky as the "treasure box," as JAXA calls it, plummets through the atmosphere at 7.5 miles per second. About 6 miles above the ground, the capsule should deploy parachutes and drift to the desert floor of Woomera, Australia. Then it will send out a beacon to lead JAXA's retrieval team to its location.

Hayabusa-2, meanwhile, will embark on an 11-year extended mission to rendezvous with another asteroid, called 1998 KY26.

'Clues to the origin of life on Earth'

Asteroids accumulated from the leftover crumbs of our early solar system, 4.5 billion years ago. Material that didn't make it into the planets coalesced. So what scientists find in those primitive space rocks can reveal a lot about the solar system's history.

What's more, Ryugu is a C-type asteroid, which means it's rich with organic carbon molecules, water, and possibly amino acids - the building blocks for proteins that were essential to the evolution of life on Earth. Some theories posit that an asteroid first delivered amino acids to our planet.

"Organic materials are the origins of life on Earth, but we still don't know where they came from," Makoto Yoshikawa, a Hayabusa2 project mission manager, said in a briefing on Friday, according to The Guardian. "We are hoping to find clues to the origin of life on Earth by analyzing details of the organic materials brought back by Hayabusa2."

NASA and JAXA are each bringing home asteroid samples to share

NASA sent its own spacecraft to an asteroid this year: Osiris-Rex (short for the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer). The probe high-fived asteroid Bennu on October 20, landing on its surface for just six seconds to stir up dust. In that brief landing, it collected a whopping 2 pounds of sample.

That spacecraft won't return with its bounty until 2023.

But combined, the samples from Osiris-Rex and Hyabusa-2 will provide the world's first comprehensive set of pristine asteroid material. NASA and JAXA have agreed to share bits of their samples with each other for scientific study.

Portions of both agencies' asteroid samples will also be stored for future research.

"These samples returned from Bennu will also allow future planetary scientists to ask questions we can't even think of today and to be able to use analysis techniques that aren't even invented yet," Lori Glaze, the director of NASA's Planetary Science Division, said in a briefing after Osiris-Rex collected its samples.

Watch JAXA's live coverage of its first asteroid-sample return, starting 12 p.m. ET on Saturday