Thermal inertia of crater-related wind streaks on Mars

Data from the Thermal Emission Spectrometer (TES) on board the Mars Global Surveyor spacecraft are used to analyze the structure of and materials comp rising crater-related wind streaks. Comparisons of high-resolution TES albe do and TES-based thermal inertia values within and adjacent to the streaks allow us to constrain the properties of the streaks and gain insight into t heir physical structure. The majority of the analyzed Type I bright, deposi tional streaks are distinct from the surrounding terrain in albedo, but not in thermal inertia. We conclude that these streaks consist of thin deposit s of bright material greater than similar to1 mum thick but less than 1-3 m m thick. The majority of the analyzed Type I dark, erosional streaks identi fied from Viking images are now indistinct from the surrounding terrain in both albedo and thermal inertia. We conclude that these streaks have been c overed by a thin deposit of bright material greater than similar to1 pm thi ck but less than 1-3 mm thick. All of the analyzed Type II dark, deposition al streaks are distinct from the surrounding terrain in both albedo and the rmal inertia. We conclude that these streaks consist of deposits greater th an a few centimeters thick. In this case we were also able to use the therm al inertia values to estimate the particle sizes of the deposited material; the values correspond to a broad range of sand-sized particles easily mobi lized by wind, supporting the deflation/deposition theory of Type II streak formation.