美国国家航空航天局NASA每日一图-2017年月28日

The Niagara Falls of Mars


Various researchers are often pre-occupied with the quest for flowing water on Mars. However, this image from NASA's Mars Reconnaissance Orbiter (MRO), shows one of the many examples from Mars where lava (when it was molten) behaved in a similar fashion to liquid water.

In a 3D image from MRO's Context Camera, the northern rim of a 30-kilometer diameter crater situated in the western part of the Tharsis volcanic province is shown. (See the HiRISE 3D image as well.) The image shows that a lava flow coming from the north-northeast surrounded the crater rim, and rose to such levels that it breached the crater rim at four locations to produce spectacular multi-level lava falls (one in the northwest and three in the north). These lava "falls" cascaded down the wall and terraces of the crater to produce a quasi-circular flow deposit. It seems that the flows were insufficient to fill or even cover the pre-existing deposits of the crater floor. This is evidenced by the darker-toned lavas that overlie the older, and possibly dustier, lighter-toned deposits on the crater floor.

This image covers the three falls in the north-central region of the crater wall. The lava flows and falls are distinct as they are rougher than the original features that are smooth and knobby. In a close-up image the rough-textured lava flow to the north has breached the crater wall at a narrow point, where it then cascades downwards, fanning out and draping the steeper slopes of the wall in the process.

This is a stereo pair with ESP_050472_1585.

The map is projected here at a scale of 50 centimeters (19.7 inches) per pixel. [The original image scale is 54.5 centimeters (21.5 inches) per pixel (with 2 x 2 binning); objects on the order of 164 centimeters (64.6 inches) across are resolved.] North is up.

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.

Image credit: NASA/JPL-Caltech/Univ. of Arizona

Last Updated: June 28, 2017
Editor: Tony Greicius

尼亚加拉瀑布的火星

各种研究人员经常预先占领,寻求在火星上流动的水。然而,来自NASA的火星侦察轨道器(MRO)的这幅图像显示了火星的许多例子之一,熔岩(熔融时)与液态水类似。

在MRO的上下文相机的3D图像中,显示了位于Tharsis火山省西部的30公里直径的火山口的北部边缘。 (参见HiRISE 3D图像。)图像显示来自北北东北部的熔岩流包围着火山口边缘,并且上升到这样的水平,它在四个位置破坏了火山口边缘,以产生壮观的多层次熔岩瀑布(一个在西北,三个在北部)。这些熔岩“瀑布”沿着火山口的墙壁和梯田逐渐下降,产生准圆形流动矿床。似乎流量不足以填补或甚至覆盖预先存在的火山口地层。这是由深色调的熔岩覆盖在火山口地板上的较老的,可能是更粉尘更轻的沉积物。

这幅画涵盖了火山口墙中北部三个瀑布。熔岩流和瀑布是独特的,因为它们比原来的光滑和旋转特征更粗糙。在特写形象中,北部的粗糙的熔岩流动在狭窄的地方突破了火山口的墙壁,然后在那里向下瀑布,在过程中扇出和悬垂更陡峭的斜坡。

这是与ESP_050472_1585的立体声对。

地图在这里以每像素50厘米(19.7英寸)的尺度投影。 [原始图像尺度为每像素54.5厘米(21.5英寸)(2 x 2合并); 164厘米(64.6英寸)的物体被解决。]北方向上。

美国亚利桑那大学图森公司运营的HiRISE由美国科罗拉多州博尔德市的Ball Aerospace&Technologies Corp.建造,美国航空航天局喷气推进实验室是美国加利福尼亚州帕萨迪纳省加州理工学院的一个部门,管理美国宇航局科学任务总监的火星侦察轨道器项目,华盛顿。

图片来源:NASA / JPL-Caltech / Univ。的亚利桑那州

最后更新:2017年6月28日
编者:Tony Greicius

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