I've seen this image taken of streamlined "islands" in the Chryse region on Mars,photographed by Mariner 9,I'll try and post the link here.The image is striking and looks like a Farman #3 Strut,or Eiffel cone,etc.The web address (just in case the my experiment fails) is :
www.astros.Isa.umich.edu/~cowley/teardrop.jpg http://www.astro.lsa.umich.edu/~cowley/teardrop.jpg