Sunlight is an important cause of damage to plastics, textiles, paints, and other organic materials. Short wavelength ultraviolet light has long been recognized as being responsible for most of this damage2. Spectroradiometric measurements were made to quantify the wide variations in UV content of sunlight under the following conditions: direct summer sunlight, winter sunlight, sunlight filtere...

Introduction: The term " space weathering " refers to the cumulative effects of several processes operating at the surface of any solar system body not protected by a thick atmosphere. These processes include cosmic and solar ray irradiation, solar wind im-plantation and sputtering, as well as micrometeorite bombardment [e.g. 1 and references therein]. In lunar soils the most voluminous weather...

[1] We developed a process-oriented hillslope soil mass balance model that integrates chemical and physical processes within hillslope soils. The model explicitly factors that soil chemical weathering at any hillslope position is related to the flux of soil eroded from upslope as well as soil production from underlying bedrock. The model was merged with measurements of soil elemental chemistry ...

[1] Mineral weathering and chemical denudation of terrestrial environments are understood by both geochemists and ecologists to be affected by rooted plant growth. We used unique 20-year ‘‘sandbox’’ experiments to test the predictions of both disciplines regarding the influence of tree growth and harvest on chemical weathering and denudation of Ca, Mg and K. Results showed 3 temporal phases: 1)...

Introduction: Orbiter and lander/rover studies of Mars' surface have identified and provided preliminary characterization of surficial materials including igne-ous and sedimentary rocks, possible volcaniclas-tic/pyroclastic rocks, and unconsolidated sediment. Some surfaces expose unaltered anhydrous silicates (militating against extensive interactions with water), but most results (including st...

Introduction: Spectroscopic observations offer the best means to evaluate chemical weathering on Mars at regional and global scales. Near-infrared (NIR) spectral data from OMEGA and CRISM have revealed hydrated minerals that indicate aqueous alteration, including different clay minerals [1-3], sulfates [1,4], silica [5], and carbonates [6], which are regionally localized across the Martian high...