11.15 Extraterrestrial Aeolian Landscapes Chapter uri icon

abstract

  • Over the last half century, spacecraft visits to the many worlds in our Solar System have revealed that the surfaces of no fewer than four planetary bodies are subject to aeolian processes. These worlds beyond Earth include the planets Venus and Mars, as well as a moon of Saturn, Titan. Each body shows the influence of the wind in a unique way, with our understanding strongly controlled by the quantity and type of data returned from spacecraft investigations. Of these worlds, the best studied is Mars, which is prone to dust storms and is freckled with bedforms, yardangs, and wind streaks. Venus is spanned by thousands of wind streaks, but bedforms and yardangs are rare (or unresolved by available data). Now known to be the sandiest world in the Solar System, Titan's equator is belted by vast sand seas made of hydrocarbon grains. Although conditions vary widely across the Solar System, the depositional and erosional processes acting on these worlds are in many ways similar to those observed on Earth. As a result, concepts and methods developed for studying terrestrial aeolian landforms can be applied to their planetary counterparts. The factors controlling dune field sediment state are the same (sediment supply, availability, and wind transport capacity), although they are commonly controlled by very different processes on other worlds. Emergent structures (i.e., bedforms) are self-organized; thus, they are controlled by dune-scale processes regardless of where they form, so that extraterrestrial dune field patterns may be analyzed with the same techniques used on Earth (e.g., pattern analysis, gross bedform-normal transport). Scaling relationships for elementary bedforms have been developed, which correlate well with bedforms formed under varying conditions. However, these relations do not appear to hold everywhere (particularly on Venus and Titan); this may be a result of low resolution data that cannot resolve elementary features of the predicted size. Although not well observed on Venus or Titan, deflation and abrasion are active processes on Mars, scouring dusty surfaces and eroding materials into yardangs and ventifacts. However, it is likely that the timescales of erosion are much longer on Mars than on Earth. Continuing studies show that aeolian landscapes beyond Earth can appear at once hauntingly familiar and exotically alien. Although there are many fundamental unanswered questions about aeolian processes on Mars, Venus, and Titan, it is clear that this juxtaposition occurs because the processes that produce aeolian landscapes on Earth also operate elsewhere, but they do so under vastly different conditions and over very different time- and length-scales. © 2013 Elsevier Inc. All rights reserved.

author list (cited authors)

  • Fenton, L. K., Ewing, R. C., Bridges, N. T., & Lorenz, R.

citation count

  • 5

Book Title

  • Treatise on Geomorphology

publication date

  • January 2013