Hayabusa2's sample capsule is coming home with the first ever pieces of rock from beneath an asteroid's surface. At around 9:30 p.m. PT, the Japan Aerospace Exploration Agency (JAXA) announced the capsule had separated from the Hayabusa2 spacecraft and was on track to land in the Australian outback in just over 12 hours time. It contains samples obtained from near-Earth asteroid Ryugu, a spinning top-shaped rock orbiting the sun between the Earth and Mars.
The separation occurred around 140,000 miles above the Earth, with the spacecraft traveling at around 7.2 miles per second. JAXA scientists will now prepare for the capsule's reentry process and retrieval in a region north of Woomera, an Australian outback town.
The control room in Sagamihara, Japan, erupted in applause and celebration at 9:35 p.m. PT, approximately five minutes after separation occurred.
"This is such a great and thrilling moment in the history of space," Niklas Reinke, director of the German Space Agency's Tokyo Office, said during a press conference after the separation. Germany's Space Agency, DLR, formed a critical part of the mission. It helped build the MASCOT lander, which took images from the surface of Ryugu in Oct. 2018.
The sample capsule will enter the atmosphere at exactly 9:28:27 a.m. PT, according to JAXA. When the capsule dives deeper, friction will create a bright fireball, blazing across the sky in some parts of southern Australia. Landing will occur approximately 20 to 30 minutes later.
JAXA is providing a livestream of the event, which will take place early Saturday morning in the US (and very early Sunday morning, Australian time), though they can't promise that any vision of the fireball will be relayed during the stream. You can find out how to watch that here.
I'm currently stationed in the outback mining town of Coober Pedy, about 500 miles from the nearest Australian capital city. It's one of the best locations to see the fireball, but the weather has been uncooperative so far. Still, it's expected to clear up. Keep checking CNET for info on the capsule's return over the weekend.
After traveling 3.2 billion miles (5.2 billion kilometers) to Ryugu and back, Hayabusa2's major mission is over. When the first Hayabusa mission returned samples from asteroid Itokawa in 2010, it burnt up in the atmosphere spectacularly. The same fate doesn't await the sequel. The probe made several slight trajectory correction maneuvers after releasing the sample capsule. During its extended mission, it'll make a flyby of asteroid 2001 CC21 in 2026 and then rendezvous with another small body, 1998 KY26, in 2031.
Sample-recovery missions provide invaluable tools for scientific discovery. They can reveal secrets from otherworldly bodies in our cosmos, like the moon, and teach us about the formation and evolution of our solar system. JAXA has led the way with asteroid sampling, making its first breakthrough in 2010 when it returned samples from asteroid Itokawa, but the mission was plagued with problems and nabbed only a small amount of material.
But the history of sample recovery missions extends much farther back. In the 1970s, Russia and the US brought samples back from the surface of the moon during the Apollo and Luna missions, but few missions have flown since.
Now the missions are experiencing a mini renaissance. In October, NASA's Osiris-Rex spacecraft touched down on asteroid Bennu in a mission that was almost too successful. The spacecraft was able to pick up so much in the way of rocks and dirt that it struggled to close its sample capsule. It'll return to Earth in 2023.
And the moon isn't missing out on any of the sneaky snatch-and-grabs, either. This week, China announced that its Chang'e 5 mission had landed on the moon and collected samples from the surface. The samples are expected to return to China in mid-December.