Motion of dust ejected from the surface of asteroid (101955) Bennu
|Author:||Jiang, Yu1,2,3; Schmidt, Jürgen3|
1State Key Laboratory of Astronautic Dynamics, Xi'an Satellite Control Center, Xi'an, China
2School of Aerospace Engineering, Tsinghua University, Beijing 100084, China
3Astronomy Research Unit, University of Oulu, Oulu, Finland
|Online Access:||PDF Full Text (PDF, 2.4 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2020120299041
|Publish Date:|| 2020-12-02
From Jan. 6, 2019 to Feb. 18, 2019, OSIRIS-REx observed asteroid (101955) Bennu ejecting 11 plumes of dust, of which part is escaping and another part is re-captured by the asteroid. The relative magnitudes of the typical forces acting on the emitted dust are quite different from the environments of the planets and other minor planets in the solar system. Here we show that ejected dust grains from the surface of Bennu can be caught in the gravitational field of Bennu. To this end, we calculated numerically the trajectories of dust grains of various sizes, from the 0.1μm to the ten millimeter range. The shape and the fate of an emitted cloud of particles depend on the size of the grains: smaller grains form a more narrowly confined dust trail while trails formed by larger grains disperse more rapidly. Four different fates are possible for ejected dust. All grains with radius less than 1.0μm, directly re-impact on Bennu or they escape directly. In contrast, a fraction of grains with a radius larger than 10.0 μm will impact or escape only after performing a number of non-Keplerian revolutions around Bennu. Our findings show how dust grains may populate the vicinity of Bennu and other active asteroids and that they can reach interplanetary space and other celestial bodies, implying that organic matter can be transported from carbonaceous asteroids to other celestial bodies, including Earth.
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
115 Astronomy and space science
Yu Jiang was supported by National Natural Science Foundation of China (11772356) and China Scholarship Council (201703170036).
© 2020 The Author(s). Published by Elsevier Ltd. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).