火星快车拍摄的火星表面3D图象

This picture was taken by the High Resolution Stereo Camera (HRSC) onboard ESA's Mars Express orbiter, in colour and 3D, in orbit 32 on 19 January 2004. It shows a three-dimensional oblique view of the summit caldera of Albor Tholus, a volcano in the Elysium region. The caldera has a diameter of 30 km and a depth of 3 km. The volcano as a whole has a diameter of 160 km and a height of 4.5 km. This is geologically interesting, since the depth of the caldera approaches the height of the volcano, which is unusual on Earth. On the far left rim of the caldera, a bright 'dust fall' seems to flow from the surrounding plateau into the caldera.

该照片是火星快车高分辨率立体相机拍摄的Elysium区域Albor Tholus火山口顶。有趣的是，该火山口深度几乎与火山高度相当。

Mars Express HRSC image 14 January 2004
Picture taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express orbiter on 14 January 2004 under the responsibility of the Principal Investigator Prof. Gerhard Neukum. It was processed by the Institute for Planetary Research of the German Aerospace Centre (DLR), also involved in the development of the camera, and by the Institute of Geosciences of the Freie Universität Berlin.
It shows a portion of a 1700 km long and 65 km wide swath which was taken in south-north direction across the Grand Canyon of Mars (Valles Marineris). It is the first image of this size that shows the surface of Mars in high resolution (12 metres per pixel), in colour and in 3D. This perspective view is computer-generated from the original image data.

该图是高分辨率立体相机拍摄的水手谷内一片1700公里长，65公里宽的区域

Crater Gusev - HRSC image 16 January 2004
This picture was taken by the HRSC in color and 3D in orbit 24 on 16 January 2004. It shows perspective oblique view of the ancient impact crater Gusev. This crater with a diameter of 160 km probably hosted a lake, as inferred from the existence of an inflowing channel called Ma´adim Vallis. The Mars rover “Spirit” of NASA will search for traces of water in the possible sediments of the lake. It landed almost exactly in the middle of the shown image, at the geographic coordinates 14.5718°S and 175.4785°E.
勇气号火星车的着陆点——Gusev环形山

怎么知道就是火山呢？好象看不出来