论文标题
释放大气中的火星灰尘在沙纹撞击中
Releasing Atmospheric Martian Dust in Sand Grain Impacts
论文作者
论文摘要
通过盐盐期间的沙粒的撞击，将灰尘的大小最大为几微米被认为是火星大气中的灰尘来源。为了研究这一灰尘分数，我们进行了实验室影响实验。直径约为200 \ textmu {} m的少量颗粒影响了模拟的火星土壤（Bimodal \ textit {Mars global Simulant}）。冲击发生在真空中的$ \ sim 18^\ circ $的角度，影响速度为$ \ sim 1 \ rm m/s $。在相邻的显微镜载玻片上捕获排出的灰尘，发现发射的粒径分布（PSD）与土壤PSD有关。我们发现，这些谷物越小，粘土大小的灰尘的弹出变得越来越困难。然而，尽管具有强大的内聚力，但单个影响的尘埃散发出1 \ textmu {} m且较少的灰尘，即可能悬浮在火星大气中的尺寸范围内的灰尘。更一般而言，弹出给定尺寸的灰尘的概率可以以尺寸范围为0.5 \ textmu {} m和5 \ textmu {} m（直径）之间的功率定律来表征。
Emission of dust up to a few micrometer in size by impacts of sand grains during saltation is thought to be one source of dust within the Martian atmosphere. To study this dust fraction, we carried out laboratory impact experiments. Small numbers of particles of about 200\textmu{}m in diameter impacted a simulated Martian soil (bimodal \textit{Mars Global Simulant}). Impacts occurred at angles of $\sim 18^\circ$ in vacuum with an impact speed of $\sim 1 \rm m/s$. Ejected dust was captured on adjacent microscope slides and the emitted particle size distribution (PSD) was found to be related to the soil PSD. We find that the ejection of clay sized dust gets increasingly harder the smaller these grains are. However, in spite of strong cohesive forces, individual impacts emit dust of 1\textmu{}m and less, i.e. dust in the size range that can be suspended in the Martian atmosphere. More generally, the probability of ejecting dust of a given size can be characterized by a power law in the size range between 0.5\textmu{}m and 5\textmu{}m (diameter).
