/Japan Lands Probe on Dangerous Asteroid

Japan Lands Probe on Dangerous Asteroid

Hyabusa-2 Illustration by Akihiro Ikeshita

As the topic of aliens from other planets heats up, Japan is making its own exciting news in space. In December 2014, the Japan Aerospace Exploration Agency (JAXA) launched the probe Hayabusa-2 with the sole purpose of exploring a one and a half mile diameter diamond shaped asteroid named Ryugu. Although most asteroids orbit in the asteroid belt between Mars and Jupiter, Ryugu sometimes orbits between Mars and Earth, which makes it closer and easier to examine. Never before has anyone landed a probe on an asteroid, so this was to be big news. In February of 2019, Hayabusa-2 actually landed on Ryugu and took samples from just below the surface. Unfortunately, since the samples were so close to the surface, they were more than likely affected by the harsh conditions of space. In order to get deeper samples that weren’t likely to have been affected by cosmic rays and charged particles, they would need to leave the asteroid, hover just above its surface, and blast a crater into into Ryugu.

Photograph of the asteroid Ryugu

In April of 2019, Hayabusa-2 fired a copper bullet from a cannon into the asteroid to loosen much of the rocky surface and materials underneath. Copper explosives were used so that when samples were collected, JAXA could tell what was part of the asteroid and what came from the explosion. The type of asteroid Ryugu is, Dark C, does not naturally contain copper. There are three types of asteroids. Bright S asteroids are usually made up of metallic iron and silicates. Bright M asteroids are mostly made up of metallic Iron. And then there are Dark C asteroids, which are made up of carbon, water, and amino acids, the building blocks of life. They are the most primitive asteroids and are believed to have come into existence within 10 million years of the formation of the Earth.

On July 10th of 2019, Hayabusa-2 landed on Ryugu again to collect the deeper samples. This was a tricky situation, as it consisted of a careful landing and firing a tantalum bullet to further loosen the asteroid material, pushing some into the sampling horn built into the probe. Tantalum was used for the same reason as copper, because it is not native to the asteroid. It was made much more difficult because Ryugu’s surface is very rocky. The mission was quite dangerous for the expensive probe and could have just as easily gone bad. When Hayabusa-2 touched down, the JAXA scientists cheered with joy. “Everything has progressed quite smoothly and I am very happy,” said Akira Fujiwara, honorary professor of the Institute of Space and Astronautical Science (ISAS), as the success was announced.

“These images were taken before and after touchdown by the small monitor camera (CAM-H). The first is 4 seconds before touchdown, the second is at touchdown itself and the third is 4 seconds after touchdown. In the third image, you can see the amount of rocks that rise,” JAXA tweeted.

What’s next for Hyabusa-2? It is set to release a much smaller lander, named MINERVA-II-2 on the surface of Ryugu. MINERVA-II-2 will release a small rover, called ROVER-II onto the surface for further exploration. ROVER-II is equipped with cameras and a thermometer and will hop like a frog to explore the rocky terrain. It’s purpose will be much the same as the Mars rover, to continue to gather data and pictures. Hyabusa-2 will leave for home in December of 2019. It will take about a year for it to make the 5.5 million mile journey back to Japan so that JAXA scientists can examine its findings.

Japanese scientists view this as just the beginning. Hitoshi Kuninaka, the director general of Japan’s Institute of Space and Astronautical Science said before the mission, “We would like to cover Mercury all the way to Jupiter.”

NASA is also working with asteroids. As we speak, the probe OSIRIS-REx, is orbiting Bennu, a much smaller Dark C asteroid. It has been there since August of 2018. Bennu is believed to have broken off from a much larger asteroid and is estimated to be 4.5 billion years old, the same as the Earth. OSIRIS-REx will orbit the asteroid until 2020, when it will land for a very brief few seconds to blast nitrogen gas at Bennu, which will stir up valuable samples. Due to Bennu’s old age, NASA speculates that it may contain organic molecules similar to the ones that are responsible for life on Earth. The probe would then return to Earth in 2023.

Left: The asteroid Bennu Right: A depiction of OSIRIS-REx

JAXA and NASA plan to exchange data and samples from these missions in hopes to learn more about the origins of life and the evolution of materials in the solar system. JAXA also expects the data from these missions to give them valuable knowledge on intercepting future asteroids that may be on a collision path with Earth. It is also seen as a step towards manned exploration of asteroids.