论文标题
弹射物的迁移是Ryugu赤道山脊的可能起源
Ejecta emplacement as the possible origin of Ryugu's equatorial ridge
论文作者
论文摘要
日本航天器Hayabusa 2访问了小行星（162173）Ryugu，并提供了许多高分辨率的表面图像，表明Ryugu具有带有突出的赤道山脊的旋转形状，就像其他小行星报道的形状一样。在这项研究中，通过数十个数值计算，我们证明在快速旋转期间，可以将在较低和中部形成的陨石坑中的弹出物沉积在赤道脊上。假设旋转周期为3小时，我们估计可以在128（+47 / -27）My用于主要皮带的小行星中产生50 m高度的赤道脊，或者3.1（+4.2 / -1.2）Gy用于近地小行星。因此，赤道脊可以在主带内的平均平均碰撞寿命内形成，但对于接近地球的小行星而言，赤道可以形成。此外，我们的模型可以解释为什么赤道山脊上发生蓝色（年轻）材料。
The Japanese spacecraft Hayabusa 2 visited the asteroid (162173) Ryugu and provided many high-resolution images of its surface, revealing that Ryugu has a spinning-top shape with a prominent equatorial ridge, much like the shapes reported for some other asteroids. In this study, through dozens of numerical calculations, we demonstrate that during a period of fast rotation, ejecta from craters formed at lower and mid-latitudes can be deposited on the equatorial ridge. Assuming a rotation period of 3 h, we estimate that an equatorial ridge with a height of 50 m can be generated in 128(+47 / -27) My for a main-belt asteroid, or 3.1(+4.2 / -1.2) Gy for a near-Earth asteroid. Therefore, an equatorial ridge can form within the average mean collisional lifetime of a km-sized asteroid within the main belt, but not for near-Earth asteroids. Furthermore, our model may explain why blue (younger) material occurs on the equatorial ridge.
