Collisional formation of top-shaped asteroids and implications for the origins of Ryugu and Bennu
抄録
<jats:title>Abstract</jats:title><jats:p>Asteroid shapes and hydration levels can serve as tracers of their history and origin. For instance, the asteroids (162173) Ryugu and (101955) Bennu have an oblate spheroidal shape with a pronounced equator, but contain different surface hydration levels. Here we show, through numerical simulations of large asteroid disruptions, that oblate spheroids, some of which have a pronounced equator defining a spinning top shape, can form directly through gravitational reaccumulation. We further show that rubble piles formed in a single disruption can have similar porosities but variable degrees of hydration. The direct formation of top shapes from single disruption alone can explain the relatively old crater-retention ages of the equatorial features of Ryugu and Bennu. Two separate parent-body disruptions are not necessarily required to explain their different hydration levels.</jats:p>
収録刊行物
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- Nature Communications
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Nature Communications 11 (1), 2,655-, 2020-05-27
Springer Science and Business Media LLC