First in situ investigation of a dark wind streak on Mars
First in situ investigation of a dark wind streak on Mars
复制标题
首次对火星暗风条纹进行现场调查
DOI：
10.1029/2008je003102
复制
发表时间：
2008
影响因子：
--
通讯作者：
M. Golombek
中科院分区：
文献类型：
--
作者：
P. Geissler;Jeffrey R. Johnson;R. Sullivan;K. Herkenhoff;D. Mittlefehldt;R. Fergason;D. Ming;R. Morris;S. Squyres;L. Soderblom;M. Golombek
[1]子午线平原上维多利亚陨石坑北端的海湾中，出现了明显的低风速条纹。子午线平原是火星探测车机遇号进行表面调查的地点。机遇号被派去检查这些风纹中最暗的一条，并将其与风纹之间较亮走廊中相邻的土壤进行比较。两个附近的网站内和外的条纹被选为可见光和红外遥感和元素丰度测量和图像的微观土壤形态。接下来，漫游者被派去研究风条纹与障碍物的相互作用，障碍物是条纹源附近的一块小岩石。机遇号的观测表明，维多利亚风纹是玄武岩砂的沉积物，这些玄武岩砂是从火山口边缘下方的黑暗沙丘中吹出来的，特别是在通往最黑暗条纹的凹室底部。在维多利亚陨石坑的围岩中没有发现当地的沙子来源，这表明沙子是从陨石坑外供应的，目前正在逃离其临时的地形陷阱。这一过程为维多利亚陨石坑的锯齿状边缘提供了一个可能的解释，即在各种季节性风的作用下，被困的沙子被吹出陨石坑并雕刻出凹室，从而磨损了软岩。这些风纹活动率的一些指标将通过持续监测漫游者轨道的擦除来提供。
[1] Prominent low-albedo wind streaks issue from embayments at the north end of Victoria crater in Meridiani Planum, the site of surface investigations by the Mars Exploration Rover Opportunity. Opportunity was sent to examine the darkest of these wind streaks and compare it to the adjacent soil in the brighter corridor between the streaks. Two nearby sites inside and outside of the streak were selected for visible and infrared remote sensing and for elemental abundance measurements and images of the microscopic soil morphology. The rover was next sent to study the interaction of the wind streak with an obstacle, a small rock near the source of the streak. Opportunity's observations suggest that the Victoria wind streaks are deposits of basaltic sand blown out of the crater from the dark dunes nestled below the crater rim, particularly at the base of the alcove leading up to the darkest streak. No local sources of sand have been identified within the Victoria crater wall rock, suggesting that the sand is supplied from outside the crater and is presently escaping its temporary topographic trap. This process presents a possible explanation for the serrated margin of Victoria crater through abrasion of the soft rock as trapped sands are blown out of the crater and carve alcoves under various seasonal winds. Some indication of the rate of activity of these wind streaks will be provided by continued monitoring of the erasure of the rover's tracks.