article_snippet.sent: ‘neck’ region that is littered with boulders.
article_snippet.sent: The region towards the right of The top right frame shows the transition between this smooth, presumably dust-covered portion, and the layered, exposed cliffs below.
article_snippet.sent: neck’ region littered with boulders. 
article_snippet.sent: our want to a do a fly-by through one of these active regions.