Data associated with publication “Where does Titan Sand Come From: Insight from Mechanical Properties of Titan Sand Candidates”

The data files include original indentation data (load, depth, modulus, hardness) produced by a nanoindenter (Nanomechanics, Inc) for various Titan sand related materials, and AFM/SEM images of the indented cracks of some of materials. Extensive equatorial linear dunes exist on Titan, but the origin of the sand, which appears to be organic, is unknown. We used nanoindentation to study the mechanical properties of a few Titan sand candidates, several natural sands on Earth, and common materials used in the Titan Wind Tunnel, to understand the mobility of Titan sand. We measured the elastic modulus (E), hardness (H), and fracture toughness (Kc) of these materials. Tholin's elastic modulus (10.4+/-0.5 GPa) and hardness (0.53+/-0.03 GPa) are both an order of magnitude smaller than silicate sand, which is also smaller than the mechanically weak white gypsum sand. With a magnitude smaller fracture toughness (Kc=0.036+/-0.007 MPa-m^(1/2)), tholin is also much more brittle than silicate sand. This indicates that sand formation mechanisms that require liquid hydrocarbons must be possible in the equatorial regions or sand formation does not require liquid, because tholin is too soft and brittle to transport from the poles, where the current lakes and seas are, to the equator.