Or a direct hit!
Nah, more a fender bender. Does not have the radiating lines of a direct hit.
Looking at the digital terraine model at the top, it looks like a lot of erosion along the cliff faces, or are they from some other cause like wind? Looking at the large area surronding this gash it appears as if two thirds of that side is slightly depressed. Could this be a remnant depression from a massive hit while the mass was still semi-molten. If so could the gash be the result of a remnant weakness in the crust, and/or possibly a major hit on the opposite side of the planet (contra-coup injury?)?