火星上的沟壑

Gullies on Mars form during the winter, fluidized by carbon dioxide frost, and scientists monitor sites on the planet for activity throughout the year. In this mid-winter scene, a Martian gully is almost completely frosted over the pole-facing slope within the shadow.

The map is projected here at a scale of 50 centimeters (19.7 inches) per pixel. (The original image scale is 50.5 centimeters [19.9 inches] per pixel [with 2 x 2 binning]; objects on the order of 152 centimeters [59.8 inches] across are resolved.) North is up.

NASA’s Mars Reconnaissance Orbiter, launched August 12, 2005, continuously monitors the Red Planet from orbit and continues in its mission to search for evidence that water persisted on the surface of Mars for a long period of time.

Image Credit: NASA/JPL-Caltech/University of Arizona

火星上的沟壑在冬季形成，并受到二氧化碳霜的影响而流化，科学家们全年监测行星上的活动地点。在这张仲冬的照片中，火星上的沟壑几乎完全覆盖了阴影里面向极地的斜坡。

此处将地图投影为每个像素50厘米（19.7英寸）的比例。(原图比例尺为50.5厘米[19.9英寸]/像素[2×2英寸];分辨率大约为152厘米(59.8英寸)。)北面向上。

美国宇航局于2005年8月12日发射的火星勘测轨道飞行器(Mars Reconnaissance Orbiter)从轨道上持续监测这颗红色星球，并继续寻找火星表面长期存在水的证据。

图片来源:NASA/JPL-Caltech/University of Arizona