Rayed craters on Dione: Implication for the dominant surface alteration process
Rayed craters on Dione: Implication for the dominant surface alteration process
复制标题
土卫六上的射线状陨石坑：对主要表面蚀变过程的影响
DOI：
10.1016/j.icarus.2016.03.021
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发表时间：
2016
期刊：
影响因子：
3.2
通讯作者：
H.
中科院分区：
文献类型：
--
作者：
Hirata;N. and Miyamoto;H.
从最近获得的，高分辨率的图像获得的卡西尼号飞船，我们研究的模式和空间分布的射线陨石坑的土卫四。我们确定了29个直径大于2公里的射线陨石坑的土卫四的表面。射线撞击坑的密度和理论撞击坑率表明，射线在土卫四上的停留时间大约为1-50 My。如此短的保留时间被解释为是由于等离子体和E环粒子的轰击，以及暗粒子的注入（推测与在土星、土卫八和其他土星卫星上发现的暗物质相同）。我们还发现，当克瑞乌萨陨石坑的射线系统形成时，它延伸到了土卫四的大部分表面。后来，沉积在后半球上的射线系统可能被部分擦除，主要是由于暗粒子的注入，这可能也消除了该区域的其他明亮射线系统。克雷乌萨射线系统的模式意味着暗物质的注入发生在克雷乌萨陨石坑的年龄和土卫四射线的典型保留时间之前。
From recently-acquired, high-resolution images obtained by the Cassini spacecraft, we examine the patterns and spatial distributions of rayed craters on Dione. We identify 29 rayed craters with diameters larger than 2 km on Dione's surface. The density of rayed craters and theoretical cratering rates indicate that the retention time for rays on Dione can be approximately 1–50 My. Such a short retention time is interpreted to be due to bombardment of plasma and E-ring particles, as well as implantation of dark particles (presumably the same dark material found on Hyperion, Iapetus, and other saturnian satellites). We also find that when the ray system of Creusa crater was formed, it extended over most of the surface of Dione. Later, the ray system deposited on the trailing hemisphere might have been partially erased, mostly due to implantation of dark particles, which may have also removed other bright ray systems in that region. The pattern of Creusa's ray system implies that the implantation of the dark material occurred more recent than both the age of Creusa crater and the typical retention time for rays on Dione.