标题： 冥王星地质图：利用陨石坑数据理解年龄关系 显示英文标题

标题： Pluto Geologic Map: Use of Crater Data to Understand Age Relationships

摘要： 冥王星的表面展现出多种多样的地质单元，从平滑的平原到极其崎岖的山脉区域。 这些地形的年龄范围从年轻的、正在重新表面化的区域（在最高分辨率的新视野号图像中也看不到撞击坑）到古老的、严重撞击且侵蚀的区域。 在这里，我们扩展了用于制作即将由美国地质调查局（USGS）发布的1:7百万比例尺冥王星地质图的陨石坑数据分析和独立的陨石坑数据集。 我们既基于陨石坑的空间密度（每平方公里给定大小范围内的陨石坑数量）提出了相对年龄，也利用估算的冥王星上的撞击体通量提供了定量年龄（例如，20亿年）。 这里介绍的技术是专门针对USGS地质图提供的信息开发的，在这种地图中，较小的陨石坑仅被绘制为点（每个陨石坑没有具体直径信息）。 我们开发了一种新的可视化类型，称为分布式R图，以理解地质单元的相对年龄。 目前关于柯伊伯带人群和冥王星上的撞击体通量的知识存在不确定性，这导致估算的定量年龄存在较大的不确定性（大约相差一倍）。 然而，通过陨石坑分析得出的相对年龄和定量年龄仍然是研究地质事件序列的有价值工具。 冥王星拥有大面积的无陨石坑的年轻地形（13个单位占映射的高分辨率表面面积的约27%），形态差异很大，表明有各种各样的表层更新机制，无论是外部还是内部作用，很可能在冥王星的近期过去或现在仍然活跃。 显示英文摘要

摘要： Pluto's surface displays a wide variety of geologic units from smooth plains to extremely rugged mountainous expanses. These terrains range in age from young, actively resurfaced regions (no observable craters even in the highest-resolution New Horizons images) to old, heavily cratered, eroded regions. Here we expand upon the crater data analysis and the independent crater data set used in the production of a 1:7M scale geologic map of Pluto that is to be published by the United States Geologic Survey (USGS). We present both relative ages based on crater spatial density (number of craters in a given size bin per km^2) and also quantitative ages (e.g., 2 Ga) using the estimated impactor flux onto Pluto. The techniques presented here were developed specifically for the information available from a USGS geologic map, where smaller craters are mapped as points only (no specific diameter information per crater). We developed a new type of visualization, called a distributed R-plot, to understand the relative ages of the geologic units. The uncertainties in the current knowledge of the Kuiper belt populations and impactor flux at Pluto propagate to large uncertainties in the estimated quantitative ages (~a factor of two). However, both relative and quantitative ages from crater analysis were still valuable tools in developing the sequence of geologic events. Pluto has large areas of crater-free young terrains (13 units making up ~27% of mapped higher-resolution surface area), with widely varying morphologies, indicating a variety of resurfacing mechanisms, both exogenic and endogenic, likely active into Pluto's recent past or present.