Japan’s asteroid sample return mission lands in the Australian desert

After spending six years in space, a Japanese spacecraft has just landed in the South Australian desert, bringing a small cache of asteroid rocks to the surface of the Earth. It is only the second time in history that materials from an asteroid have been returned to our planet. Finally, scientists will open the spacecraft and discover the precious rocks it contains to learn more about the asteroids that pervade our Solar System.

The landing is the culmination of Japan’s Hayabusa2 mission, which aims to bring samples of an asteroid to Earth. After its launch from Japan in 2014, the Hayabusa2 spacecraft spent four years traveling towards an asteroid called Ryugu. The rover spent a year and a half circling the asteroid, mapping the rock’s surface and taking material samples before returning to Earth.

Scientists are eager to see the rocks Hayabusa2 has returned, as pristine samples from an asteroid could tell us much more about what our Solar System was like when the planets were first forming. That’s because asteroids are a bit like images of babies from our cosmic neighborhood. These space rocks have been around since the dawn of the Solar System, and scientists believe that asteroids haven’t changed much in the last 4.6 billion years. These objects contain many of the same materials that were present at the birth of the Solar System, so studying these rocks in labs here on Earth could provide key context about the early days of the planets.

Photo by STR / JIJI PRESS / AFP via Getty Images

The capsule will be transported to Japan, where we will learn how much asteroid material the mission gathered. The Japan Aerospace Exploration Agency (JAXA), which oversees the mission, hoped to recover 100 milligrams of material from Ryugu, but scientists had no way to measure how much sample Hayabusa2 had collected while in space. That exact amount will be revealed when the spacecraft opens in Japan.

Hayabusa2 used some creative techniques to collect his samples on Ryugu. Equipped with a small horn-shaped arm, the spacecraft first struck the asteroid with this appendage in February 2019. When the arm made contact, it fired a bullet-like projectile that pierced the asteroid, releasing a large amount of dust and pebbles. that hopefully climbed to the horn.

However, the spaceship didn’t just take a sample on Ryugu. Hayabusa2 tried this maneuver again in July 2019, but the spacecraft had excavated a bit first. Before hitting the asteroid a second time, the ship dropped a can of explosives on Ryugu, opening a crater in the asteroid and revealing some of the rocks located just below the surface. Hayabusa2 then hit the surface inside this crater to collect some of this newly exposed material. The goal was to collect even more pristine rocks from Ryugu. The material below the asteroid’s surface has not been exposed to the harsh environment of space for billions of years, like the rocks outside, which have likely undergone some changes and reactions over time. So the crater material could provide an even better snapshot of the materials that were present when the Solar System first formed.

Image: DLR

Once the Hayabusa2 team felt confident they had taken enough of Ryugu, the spacecraft left the asteroid in November 2019. After spending the last year traveling to Earth, the spacecraft deployed a small capsule on Friday morning. night, with Ryugu’s samples inside. The capsule then sailed for Earth, sinking through our planet’s atmosphere this morning. He then deployed a parachute, slowing the vehicle to about 12 kilometers per second, or nearly 27,000 miles per hour, so it could land softly in the Woomera Forbidden Area in South Australia.

After it made landfall, JAXA teams conducted an extended search in Australia to find the capsule. The vehicle fell in an area that covers 100 square kilometers, or about 38 square miles. It also landed at night in Australia, which made the capsule even more difficult to detect. Fortunately, the capsule was equipped with a radio beacon that helped crews locate where the spacecraft landed. Before landing, JAXA teams installed five antennas around the expected landing site to help find the signal, and the agency also had a helicopter with its own beacon receiver to help narrow down the search. A drone was also available to fly over the area and take pictures.

Hayabusa2 is Japan’s second mission to retrieve samples from an asteroid. Its first mission, Hayabusa, returned asteroid samples to Earth in 2010, although the mission only managed to collect small grains of asteroid material. Hopefully Hayabusa2 collected even more than the original Hayabusa offerings. And in 2023, NASA’s OSIRIS-REx mission is expected to return the largest sample of material from an asteroid ever collected.

Although Hayabusa2 has completed its main mission, the spacecraft is not done yet. The main spacecraft is still in space and has just embarked on a search to visit another asteroid called 1998 KY26. It will take Hayabusa2 11 years to reach its new goal, with the goal of analyzing space rock and learning even more about the asteroids that surround us in space.