Dust Devil Tracks on Mars: Observation and Analysis from Orbit and the Surface Daniel Foley

1
Dust Devil Tracks on Mars Observation and
Analysis from Orbit and the Surface Daniel Foley

• Objective To observe a dust devil track from
  orbit and analyze the track on site
• The Mars Exploration Rover Spirit traversed a
  recently formed Dust Devil track
• Spirit's Microscopic Imager (MI) made
  observations of the track
• Experiments were conducted utilizing the Arizona
  State University Vortex Generator (ASUVG), to
  simulate dust devil surface interaction

2
Surface Modification On Site MER Data

• MI images were taken
• Inside the dust devil track on Sol 39
• On the contact of the dust devil track and the
  plains on Sol 52
• Outside of the dust devil track on Sol 73
• Smaller particles
• Least abundant on Sol 39
• Intermediate on Sol 52
• Most abundant on Sol 73

3
Laboratory Simulations

• Similar size particles in the bedforms were
  moved underneath the vortex to simulate dust
  devil surface interaction
• The dust devil was able to remove dust and fine
  grains while leaving behind cleaned larger grains
• Forming a linear streak retaining the relative
  albedo of the underlying layer once covered by
  fine particles

4
Dust Devil Track Formation

• Tracks observed to form in the wake of active
  dust devils observed from Spirit
• The theory that dust devils form long narrow
  streaks as relative albedo differences by
  removing dust from the surface to expose a
  darker, or different albedo substrate, has been
  further confirmed as a result of this study