Designed by JAXA, the Japanese space agency, with a contribution from the CNES, the Hayabusa2 probe was launched on December 4, 2014.
On June 27 the probe arrived, as planned, at its destination, the primitive type C asteroid (162173) Ryugu : with a diameter of about 920 meters the asteroid is at a distance of 300 million km from the Earth.
Hayabusa2 stationed itself at a distance of 20 kilometers from the target. Starting in July, it will approach the asteroid to within a distance of 5km, and will study it in detail using its instruments, until the end of 2019.
Ryugu is an asteroid whose composition is thought to be rich in organic matter (carbon and hydrated matter), hardly changed since the formation of the solar system.
During the autumn of 2018, 4 landers will be sent to its surface : one of them is the Eurpean Mascot, which was designed by the CNES and the DLR ; the 3 others, Minerva, were designed by the JAXA.
They will do in-situ observations during their short lifetime ;
Thrice, during this same period of time, the space probe will gather samples of pristine matter, very rich in organic material.
The first two sample gathering operations will take place in October 2018 and February 2019.
The third sample gathering operation will involve a projectile (moving at 2 km/s) in order to sample a deeper layer of the surface.
The probe will bring the samples back to the Earth in December 2020.
The scientific instruments
In addition to the four landers, including Mascot which is equipped with an infra-red microscope, a magnetometer and a radiometer, Hayabusa2 carries :
- a set of cameras for the spectral range ultra-violet-visible-close infra-red (ONT) ;
- and infra-red spectrometer (NIRS3) ;
- a thermal imager (TIR) ;
- a laser altimeter (LIDAR),
Unerstanding the DNA of the Solar System
Antonella Barucci is a co-invetigator of the scientific team as well as of the ONC cameras, of the NIRS3 spectrometer and of the laser (LIDAR).
With her team at the LESIA, she participates in the detailed analysis of the physical properties and composition of the surface material, and in particular the analysis of the nature and distribution of organic material and the aqueous changes (hydrated silicates) on the surface of Ryugu.
Astronomers hope that a study of these small bodies will: :
- lead to a better understanding of the properties of the primitive, perhaps pre-solar, matter in the solar system ;
- and thence to an understanding of the primordial conditions reigning during the origin and formation of planets, and the emergence of life.
- In contrast to the planets, which have undergone changes during their lifetime, most asteroids have presumably, because of their small size, a trace of the original composition of the proto-planetary disc from which the solar system was formed.
The mission will thus furnish an answer to the following questions :
- What were the processes in operation in the early solar system, during the formation of the planets ?
- What were the physical properties and the evolution of the basic units from which the terrestrial plants were formed ?
- Do the primitive type near-Earth objects contain pre-solar material ?
- What is the nature and origin of the organic material in primitive asteroids, and how can these latter help us understand the origin of the molecules vital to the emergence of life ?
