Tuesday, April 1, 2014

Highlights – The Curious Queso of Aged Martian Sediment

For years, children and readers of 16th and 17th century English literature have fancied the notion of the Proverbs of John Heywood that claimed that “the moon is made of a greene cheese.” Although the proverb has been largely ignored for centuries, new explorations of surface sediment on Mars have re-opened the controversy, albeit on a different celestial body. In this study, Greenman and Neila describe observations of slope angles and grain sorting trends from the Martian surface west of Caseus Rotula that suggest the presence of noncohesive granular materials, like many granular materials from the kitchen (e.g., coffee grinds and Brazil nuts). These data were integrated with data on ultrasonic velocity from sediment, which illustrate that velocity of the Martian surface sediment average ~1600 m/s and show temperature dependence---trends remarkably similar to published measurements of Cheddar cheese (not green cheese, however). These sediments are interpreted to reflect a primal Martian crust source (there's "cheese in the crust"?), perhaps generated as impact ejecta de brie.

Sedimentology, geomorphology, and ultrasonic velocity of Martian surface sediment, Caseus Rotula:  Implications for Martian crustal composition by L.T.L. Greenman, and I. A. Neila