An impact (on the Mars) capable of ejecting a fragment of the Martian surface into an Earth-intersecting orbit is even less probable than such an event on the Moon, in view of the Moon's smaller size and closer proximity to Earth.
一个能够把活性表面的碎片射入地球交叉轨道的碰撞发生的可能性甚至小于这种事件在月亮上发生的可能性,考虑到月亮更小的尺寸及其与地球接近的程度。