论文标题
尘埃从小行星表面弹出（101955）bennu的运动
Motion of Dust Ejected from the Surface of Asteroid (101955) Bennu
论文作者
论文摘要
从2019年1月6日到2019年2月18日，Osiris-Rex观察到小行星（101955）Bennu弹出11块灰尘，其中该部分逃脱了，另一部分由小行星重新接收。作用在发射灰尘上的典型力的相对大小与太阳系中的行星和其他次要行星的环境完全不同。在这里，我们表明，从Bennu表面弹出的灰尘颗粒可以捕获在Bennu的重力场中。为此，我们从数值上计算了各种尺寸的尘埃轨迹，从0.1MUM到十毫米范围。发出的颗粒云的形状和命运取决于谷物的大小：较小的谷物形成更狭窄的灰尘步道，而较大谷物形成的步道更快地分散。弹出灰尘可能有四种不同的命运。所有半径均小于1.0MUM的谷物，直接重新影响Bennu或直接逃脱。相比之下，只有大于10.0妈妈的半径的晶粒只有在Bennu周围进行多次非杀伤力旋转后才会影响或逃脱。我们的发现表明，粉尘颗粒如何填充Bennu和其他活跃的小行星附近，并且它们可以到达行星际空间和其他天体，这意味着有机物可以从碳质的小行星转运到包括地球在内的其他天体。
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 0.1mum 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 1.0mum, directly re-impact on Bennu or they escape directly. In contrast, a fraction of grains with a radius larger than 10.0 mum 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.
