ESA's Mars Express has returned new images of an elongated impact crater in the southern hemisphere of Mars. Located just south of the Huygens basin, it could have been carved out by a train of projectiles striking the planet at a shallow angle.
The large Huygens basin (not visible in the main image but seen in the wider contextual image) 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'.
The Astronomical Research Center (A.R.C) mentioned that one of these craters is seen in this new image, which covers an area of 133 x 53 km at 21 degrees S / 55 degrees 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.
In the early 1980s, scientists proposed that elongated impact craters were formed by incoming chains of orbital debris following trajectories that decayed with time. As the debris spiraled downwards, it eventually struck the planet at shallow angles, gouging out the elongated craters.