The scars of impacts on Mars

Although the Mars Express lander Beagle 2 unfortunately failed to deploy, the Orbiter continues to send back exciting images of the surface – Deskarati

The large Huygens basin  is about 450 km in diameter and lies in the heavily cratered southern highlands. In this area there are many impact scars but none perhaps are more intriguing than the ‘elongated craters’.

One of these craters is seen in this new image, which covers an area of 133 x 53 km at 21°S / 55°E. The scene was captured on 4 August 2010 and the smallest objects distinguishable by the camera are about 15 m across.

This unnamed elongated crater sits just to the south of the much larger Huygens basin. It is about 78 km in length, opens from just under 10 km wide at one end to 25 km at the other, and reaches a depth of 2 km. Impact craters are generally round because the projectiles that create them push into the ground before the shockwave of the impact can explode outwards. So why is this one elongated?

The clue comes from the surrounding blanket of material, thrown out in the initial impact. This ‘ejecta blanket’ is shaped like a butterfly’s wings, with two distinct lobes. This hints that two projectiles, possibly halves of a once-intact body, slammed into the surface here.

via The scars of impacts on Mars.

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