A Scar in the Highlands

A Scar in the Highlands, a photo by Lunar and Planetary Institute on Flickr.

Via Flickr:
With such an abrupt beginning and end, and no obvious connection to typical geologic flow, fault or scour processes, what could have caused this curious arcuate, negative-relief landform in the lunar highland regolith (24.3°N, 245.0°E)?

This scar points toward the center of Mare Orientale, a 900 km-diameter impact feature. Several crater chains, visible in a wider view image of this area, similarly radiate from the Orientale basin. The violence of the basin-forming event was so great that it hurled prodigious volumes of target rock hundreds of kilometers across the lunar surface. The orientation and location of the featured scar pattern makes the Orientale impact a plausible cause for what we see there. In addition to rocky projectiles, ground-hugging and/or ballistically emplaced ejecta deposits are a common accompaniment to large impact features on the Moon. From their morphology and occurrence, they seem to have behaved in a very fluid-like way, and can morph and merge as they flow across the surface until losing energy and coming to rest as dunes or lobes. This image appears to be a place where advancing dunes merged and "healed over."