China pushes forward exploration of small celestial bodies
China is pushing forward its exploration of a near-Earth asteroid and a main-belt comet with one space probe, said a senior space expert on Saturday.
The mission is to send a probe around an asteroid named 2016HO3 and then land on it to collect samples, said Ye Peijian, an academic of the Chinese Academy of Sciences, at the ongoing 2021 China Space Conference, held in Nanjing, east China's Jiangsu Province.
The probe will then fly back to Earth's proximity and release a capsule to return the samples. After that, it will continue its journey. With the assistance of the gravity of Earth and Mars, it will finally arrive at the main asteroid belt and orbit comet 311P, Ye said, adding that the whole process will take about ten years.
Asteroid 2016HO3 has a very close relationship with Earth. It has a diameter of about 40 to 100 meters, said Ye.
The second target, comet 311P, is one of the comets within the main asteroid belt. The diameter of its cometary nucleus is about 320 to 580 meters, he said.
Small celestial bodies preserve the original information of the formation and evolution of the solar system. They are considered living fossils for studying the origin of the solar system.
Probing small celestial bodies is a new frontier of space exploration, but with a high threshold. The main difficulties are the uncertainties and the unknown environment of the small bodies. It's hard to learn about their shape, composition, structure, and other features through observation from Earth, Ye said.
Compared with Japan and the United States, which have collected samples by touching asteroids, China has designed multiple sampling methods in its mission, including touch, hovering, and landing, hoping to collect more samples by landing.
The mission's scientific objective includes probing the surface composition, internal structure, and other features of the two targets. It also includes detecting possible water and organics on the comet and studying the formulation and evolution of the solar system, said Ye.
He also said that the probe would carry scientific payloads, including navigation sensors, multispectral cameras, detection radar, thermal radiation spectrometers, and particle analyzers.
The mission would make a new contribution to the country's deep space exploration and planetary science development, said Ye.