The origin of the interstellar object 1I/‘Oumuamua has defied explanation. In a companion paper (Jackson & Desch, 2021), we show that a body of N₂ ice with axes 45 m × 44 m × 7.5 m at the time of observation would be consistent with its albedo, nongravitational acceleration, and lack of observed CO or CO₂ or dust. Here we demonstrate that impacts on the surfaces of Pluto‐like Kuiper belt objects (KBOs) would have generated and ejected ∼10¹⁴ collisional fragments—roughly half of them H₂O ice fragments and half of them N₂ ice fragments—due to the dynamical instability that depleted the primordial Kuiper belt. We show consistency between these numbers and the frequency with which we would observe interstellar objects like 1I/‘Oumuamua, and more comet‐like objects like 2I/Borisov, if other stellar systems eject such objects with efficiency like that of the Sun; we infer that differentiated KBOs and dynamical instabilities that eject impact‐generated fragments may be near‐universal among extrasolar systems. Galactic cosmic rays would erode such fragments over 4.5 Gyr, so that fragments are a small fraction (∼0.1%) of long‐period Oort comets, but C/2016 R2 may be an example. We estimate ‘Oumuamua was ejected about 0.4–0.5 Gyr ago, from a young (∼10⁸ yr) stellar system, which we speculate was in the Perseus arm. Objects like ‘Oumuamua may directly probe the surface compositions of a hitherto‐unobserved type of exoplanet: “exo‐Plutos.” ‘Oumuamua may be the first sample of an exoplanet brought to us.

中文翻译：

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1I /'Oumuamua作为外泌冥王星表面的N2冰碎片II：N2冰碎片的产生和'Oumuamua的起源

星际物体1I /'Oumuamua的起源已被拒绝解释。在同伴论文中（Jackson＆Desch，2021年），我们显示了观测时轴为45 m×44 m×7.5 m的N ₂冰块与其反照率，非重力加速度和缺乏观测相符。 CO或CO ₂或粉尘。在这里，我们证明了对冥王星状柯伊伯带天体（KBOs）表面的撞击会产生并喷射出约^{10 14个}碰撞碎片，其中大约一半是H ₂ O冰碎片，一半是N ₂冰块-由于动力学的不稳定性耗尽了原始的柯伊伯带。我们展示了这些数字与观测1I /'Oumuamua等星际物体以及2I / Borisov等更像彗星的物体之间的频率之间的一致性，如果其他恒星系统能像太阳那样高效地射出此类物体的话。我们推断出，射出撞击产生的碎片的KBO和动力学不稳定性可能在太阳系外系统中几乎是普遍的。银河系宇宙射线会侵蚀此类碎片超过4.5 Gyr，因此碎片仅占长周期奥尔特彗星的一小部分（约0.1％），但C / 2016 R2可能是一个例子。我们估计，'Oumuamua大约是在0.4-0.5 Gyr之前从一个年轻人中弹出的（〜10 ⁸ yr）恒星系统，我们推测它位于英仙座。诸如“ Oumuamua”之类的物体可以直接探测迄今未观察到的系外行星：“ exo-Plutos”的表面成分。“ Oumuamua可能是带给我们的系外行星的第一个样本。