A Crater on a Crater Wall

It's not that common to see craters on steep hills, partly because rocks falling downhill can quickly erase such craters. Here, however, NASA's Mars Reconnaissance Orbiter (MRO) observes a small impact has occurred on the sloping wall of a larger crater and is well-preserved. Dark, blocky ejecta from the smaller crater has flowed downhill (to the west) toward the floor of the larger crater. Understanding the emplacement of such ejecta on steep hills is an area of ongoing research. https://photojournal.jpl.nasa.gov/catalog/PIA21758