On December 6, 2020, the Japanese spaceship Hayabusa2 will return close to the Earth and lower a capsule in the Australian desert. The capsule will contain a precious package: a few grams of the asteroid Ryugu.
This adventure began on December 3, 2014, when JAXA, the Japanese space agency, launched the space probe Hayabusa2. Destination: the asteroid 162173 Ryugu, located 340 million kilometers from the Earth.
The exploration of Ryugu
In June 2018, Hayabusa2 reached its target and began an extended study of the asteroid. For a year and a half, the probe surveyed Ryugu in all its aspects. It even released four small capsules to its surface.
The crux of the Hayabusa2 mission is to collect fragments from the asteroid and bring them back to Earth.
So, in February 2019, the probe slowly approached the asteroid’s surface and fired a tantalum projectile to release rock fragments. Some of these were then sucked up by a horn, to be stored in the return capsule.
In April 2019, a copper impactor was fired at the surface, creating a small crater on the asteroid. Then, in July, the probe approached the asteroid once again, this time to collect soil samples from inside the crater.
Why bring samples back to Earth?
Planets like the Earth were formed by the agglomeration of matter that was transformed over time.
Asteroids were formed in the same way, but the transformation stopped earlier. Some asteroids are even made up of matter that evolved very little since the beginning of the solar system. Studying those asteroids allows us to understand which materials the Earth was formed with.
In addition, Ryugu is a type of asteroid containing organic compounds. Those compounds are the basis of life on Earth, and studying those bodies could shed light on the processes that led life to develop on our planet.
Hayabusa2 confirmed that the matter making up Ryugu is very brittle. Meteorites of this type of asteroid that enter the Earth’s atmosphere disintegrate easily and rarely reach the ground, which makes the samples brought back by Hayabusa2 so valuable.
We don’t yet know the quantity of samples collected by Hayabusa2. We have to wait for the return of the capsule to find out for certain. But there’s no doubt that Japanese astronomers can’t wait to unwrap their celestial Christmas present.