论文部分内容阅读
The primitive asteroids are those remnant building blocks in the Solar system formation.They provide key clues for us to make in-depth understanding of the process of planetary formation,the complex environment of early Solar nebula,and even the occurrence of life on Earth.On 13 December 2012,Change-2 completed a successful flyby of the near-Earth asteroid 4179 Toutatis at a closest distance of 770 meters from the asteroids surface.