Ejecta emplacement as the possible origin of Ryugu's equatorial ridge

The Japanese spacecraft Hayabusa 2 visited the asteroid (162173) Ryugu and provided many high-resolution images of its surface, revealing that has a spinning-top shape with prominent equatorial ridge, much like shapes reported for some other asteroids. In this study, through dozens numerical calculations, we demonstrate during period fast rotation, ejecta from craters formed at lower mid-latitudes can be deposited on ridge. Assuming rotation 3 h, estimate an ridge height 50 m generated in 128(+47 / -27) My main-belt asteroid, or 3.1(+4.2 -1.2) Gy near-Earth asteroid. Therefore, form within average mean collisional lifetime km-sized main belt, but not Furthermore, our model may explain why blue (younger) material occurs