It has been proposed that Mars' moons formed from a disk produced by a large impact with the planet. However, whether such an event could produce tiny Phobos and Deimos remains unclear. Using a hybrid N-body model of moon accumulation that includes a full treatment of moon-moon dynamical interactions, we first identify new constraints on the disk properties needed to produce Phobos and Deimos. We then simulate the impact formation of disks using smoothed particle hydrodynamics, including a novel approach that resolves the impact ejecta with order-of-magnitude finer mass resolution than existing methods. We find that forming Phobos-Deimos requires an oblique impact by a Vesta-to-Ceres sized object with ~10^-3 times Mars' mass, a much less massive impactor than previously considered.

中文翻译：

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火卫一和火卫二的起源是灶神星到谷神星大小的天体与火星的撞击。


有人提出，火星的卫星是由与行星的强烈撞击产生的圆盘形成的。然而，这样的事件是否会产生微小的火卫一和火卫二仍不清楚。使用月球积累的混合N体模型（包括对月-月动力学相互作用的全面处理），我们首先确定了产生火卫一和火卫二所需的盘特性的新约束。然后，我们使用平滑粒子流体动力学模拟圆盘的撞击形成，包括一种新方法，该方法能够以比现有方法更精细的数量级质量分辨率来解析撞击喷射物。我们发现，形成火卫一-火卫二需要由灶神星到谷神星大小的天体进行倾斜撞击，其质量约为火星的 10 ^-3倍，这个撞击体的质量比之前认为的要小得多。