Wind-erosional landscapes on plan- etary surfaces are often dominated by yardangs, which are created by the stripping of surface materials by winds. They are long, narrow, parallel ridges having steep slopes, streamlined shapes and blunt upwind margins [1,2]. There are many similarities in their basic morphology to linear dunes, which are also long, narrow and generally parallel [3]. Yet, there is some- thing about their shape that makes it known they are yardangs and not dunes. We seek to describe general differences between yardangs and dunes in terms of basic morphology, and then to quantify these differ- ences through analyses of length, width, spacing, dis- continuousness of form and sinuosity, the latter two factors being perhaps most discriminating. In addition, analysis of radar response can help reveal material differences. If we can define the similarities and differences be- tween dunes and yardangs on Earth, then we can apply these factors to possible yardangs on other planets [4,5]. This will be especially useful where resolutions are poor, such as on Titan [6] and Venus [7]. The study of and discrimination between dunes and yardangs can reveal wind direction and strength, the presence and condition of sediments, the nature and erodability of the substrate and regional climate [1].