It has been recently recognized that the surface of sub-km asteroids in contact with the space environment is not fine-grained regolith but consists of centimeter to meter-scale rocks. Here we aim to understand how the rocky morphology of minor bodies react to the well known space erosion agents on the Moon. We deploy a neural network and map a total of ~130,000 fragmented boulders scattered across the lunar surface and visually identify a dozen different desintegration morphologies corresponding to different failure modes. We find that several fragmented boulder morphologies are equivalent to morphologies observed on asteroid Bennu, suggesting that these morphologies on the Moon and on asteroids are likely not diagnostic of their formation mechanism. Our findings suggest that the boulder fragmentation process is characterized by an internal weakening period with limited morphological signs of damage at rock scale until a sudden highly efficient impact shattering event occurs. In addition, we identify new morphologies such as breccia boulders with an advection-like erosion style. We publicly release the produced fractured boulder catalog along with this paper.
翻译:最近人们认识到,与空间环境接触的亚公里小行星表面不是精细的碎石状,而是由测量尺度岩石的厘米组成。 我们的目的是了解小物体的岩石形态如何对月球上众所周知的空间侵蚀物剂作出反应。 我们部署神经网络并绘制分布在月球表面的总共~130 000个碎裂的巨石图,并绘制分布在月球表面的总共~130 000个碎石体,并直观地识别出与不同故障模式相适应的十多种脱解形态。 我们发现,一些支离破碎的巨石形态相当于小行星本努观察到的形态,表明月球和小行星上的这些形态可能不会对其形成机制进行诊断。 我们的发现表明,在岩石碎石碎块碎块碎块过程的特点是内部衰减期有限,在岩石规模上形成有限的形态迹象,直到突然发生高效的震碎事件。 此外,我们发现了一些新的形态,如有类似腐蚀的微粒状状状的微粒状体。 我们公开释放了与这张纸一起生成的碎石雕刻。