On December 5, 2020, the Japanese Aerospace Exploration Agency (JAXA) Hayabusa 2 mission sent home a monster capsule containing debris from the near-earth asteroid (NEA) 162173 Ryugu. This was the culmination of the probe’s first six years in space, which launched in December 2014 and rendezvous with Ryugu in June 2018. As the probe focuses on its new targets, scientists will be busy analyzing of the Ryugu monster.
One thing they noticed immediately after opening the bowl on Monday (December 21st) was the black sand dust that lined the outside of the capsule. According to a statement by JAXA, the black sand is material taken from the surface of Ryugu. Considering what is in sample chamber A, it appears that the amount of material obtained by Hayabusa 2 is more substantial than previously thought.
This discovery comes just a week after the mission’s reentry capsule returned to Earth. It and the sample it contained were recovered in Woomera, Australia, on December 6, 2020, after entering the atmosphere and creating a bright streak in the sky. On December 8, the capsule was delivered to the JAXA Sagamihara Campus, where technicians began to carefully remove the sample.
On December 14th, the agency confirmed in a statement that a sample of black grains of sand believed to have come from the asteroid was found in the sample container. They apparently got stuck at the entrance to the sample collector, the container in which the samples were stored. JAXA has also released a photo of what the sooty material looked like (see above). As they said:
“JAXA has confirmed that samples derived from the asteroid Ryugu are in the sample container. We were able to confirm black, sandy-like particles believed to be from the asteroid Ryugu. We continue our work to open the Sample Collector in the Sample Container. Extraction of the sample and analysis will be performed.“
A day later, JAXA released two statements. The first announced confirmation that the obtained samples were indeed from the asteroid Ryugu. The second statement shared the results of an analysis performed on gas also contained in Sample Container A. After conducting mass spectrometry tests at the Quick Look Facility (QLF) – which was established on December 7.th, 2020 at Woomera’s local headquarters – JAXA has confirmed that the gas is coming from the asteroid.
To confirm the first results, a similar analysis was conducted on December 10 at the Extraterrestrial Sample Curation Center (ESCuC) at the JAXA Sagamihara Campus.th and 11th. These tests gave the same result, indicating that the gases are indeed the result of material obtained as part of the Ryugu sample sublimated during transport back to Earth.
This is the first time that a sample return contains material from deep within a deep-space object, not to mention material from that object that was in a gaseous state. JAXA also stated in their second statement that the analysis team will further examine the gas sample and perform “a detailed analysis of the molecular and isotopic composition of the captured gas.”
In the meantime, JAXA will “continue to open sample chambers B and C in the sample container, and the sample will be removed and analyzed by the curation group and the first analysis team,” they said. These samples included both surface dust and pristine material from below the surface shot up by an impactor fired from the probe (which was essentially an anti-tank warhead).
While in orbit around Ryugu, Hayabusa 2 also sent four small rovers – including MASCOT and Minerva-II – to the surface of the asteroid to investigate and analyze the geological context of the collected samples. Due to minimal gravity and extremely uneven surfaces, these rovers are designed to hop around instead of relying on legs, wheels or steps.
These samples are our first glimpse of a sample return mission that was six years in the making and the successor to the Hayabusa mission – which collided with asteroid Itokawa in September 2005 and brought a monster to Earth in June 2010. Then and now, the purpose of these missions was to study material left over from the formation of the solar system (which are essentially asteroids).
In addition to revealing things about the earliest periods of the solar system, the surface and interior of these asteroids are also a record of subsequent evolution over the past 4.5 billion years. To obtain samples from Ryugu, Hayabusa 2 had to travel about 300 km (200 million miles) from Earth to meet the NEA Ryugu as it passed Earth’s orbit.
Once all samples from Hayabusa 2 have been removed and analyzed, half will be shared between JAXA, NASA and other international organizations. The remainder will be saved for future research as technological advancements allow for more detailed analysis and studies. Meanwhile, Hayabusa 2 is now heading to meet with his next goals as part of his mission expansion.
This extension was granted in September 2020 for the tholine-rich (reddish-colored) asteroid 2001 CC21 and the wetland NEA 1998 KY26, which is believed to be composed of material from multiple asteroids that collided in the past. The probe will turn these asteroids into flybys in July 2026 and July 2031 (respectively).
These icy asteroids not only reveal things about the history of our solar system, they can also tell us how the water was distributed among the planets billions of years ago (making life possible)!
Read further: Phys.org, JAXA