Singer K N, McKinnon W B, Gladman B, Greenstreet S, Bierhaus E B, Stern S A, Parker A H, Robbins S J, Schenk P M, Grundy W M, Bray V J, Beyer R A, Binzel R P, Weaver H A, Young L A, Spencer J R, Kavelaars J J, Moore J M, Zangari A M, Olkin C B, Lauer T R, Lisse C M, Ennico K
Science. 2019 Mar 1;363(6430):955-959. doi: 10.1126/science.aap8628.
The flyby of Pluto and Charon by the New Horizons spacecraft provided high-resolution images of cratered surfaces embedded in the Kuiper belt, an extensive region of bodies orbiting beyond Neptune. Impact craters on Pluto and Charon were formed by collisions with other Kuiper belt objects (KBOs) with diameters from ~40 kilometers to ~300 meters, smaller than most KBOs observed directly by telescopes. We find a relative paucity of small craters ≲13 kilometers in diameter, which cannot be explained solely by geological resurfacing. This implies a deficit of small KBOs (≲1 to 2 kilometers in diameter). Some surfaces on Pluto and Charon are likely ≳4 billion years old, thus their crater records provide information on the size-frequency distribution of KBOs in the early Solar System.
“新视野号”宇宙飞船对冥王星和卡戎的飞掠，提供了柯伊伯带中布满陨石坑表面的高分辨率图像，柯伊伯带是海王星轨道之外的一个广阔天体区域。冥王星和卡戎上的撞击坑是由与其他柯伊伯带天体（KBOs）碰撞形成的，这些天体直径从约40千米到约300米不等，比大多数通过望远镜直接观测到的柯伊伯带天体小。我们发现直径小于约13千米的小陨石坑相对较少，这不能仅用地质重铺来解释。这意味着直径小于约1至2千米的小柯伊伯带天体数量不足。冥王星和卡戎上的一些表面可能有超过40亿年的历史，因此它们的陨石坑记录提供了关于早期太阳系中柯伊伯带天体大小频率分布的信息。
