NEARLY ALL OUR KNOWLEDGE OF VENUS' SURFACE COMES FROM ITS INTERACTIONS WITH ELECTROMAGNETIC (EM) RADIATION OF RADAR AND VISIBLE-TO- INFRARED WAVELENGTHS. BASALTIC LAVA ROCK COVERS MOST OF THE SURFACE OF VENUS AS SHOWN BY ITS LANDFORMS AND IN SITU CHEMICAL ANALYSES AND THE RESPONSES BASALTIC ROCK TO EM RADIATION DEPENDS CRITICALLY ON THE MINERALS (CHEMICAL COMPOUNDS) PRESENT (NOT ONLY THE BULK COMPOSITION). HOWEVER THE MINERALS ON VENUS' BASALTS WHICH INTERACT WITH EM RADIATION REFLECT CHEMICAL REACTIONS (I.E. WEATHERING) WITH VENUS' HOT CAUSTIC ATMOSPHERE. THUS TO INTERPRET EM DATA FROM VENUS ACCURATELY EVEN OLD DATA IT IS CRUCIAL TO KNOW WHICH MINERALS ARE PRODUCED AS VENUS BASALTS WEATHER AND HOW RAPIDLY THEY FORM. IN THIS PROGRAM WE WILL DETERMINE THE PROCESSES PRODUCTS AND RATES OF BASALT WEATHERING ON VENUS THROUGH LABORATORY EXPERIMENTS. WE WILL REACT BASALTIC GLASSES WITH MODEL VENUS ATMOSPHERES AT RELEVANT TEMPERATURES AND PRESSURES. WE WILL ANALYZE THE WEATHERED BASALTS WITH NANO- AND MICRO-SCALE METHODS (INCLUDING VNIR REFLECTANCES) BECAUSE WE EXPECT LIMITED REACTION PROGRESS ON THE TIMESCALES OF OUR EXPERIMENTS. TO EXTRAPOLATE OUR LAB RESULTS TO REALISTIC TIME- AND LENGTH-SCALES WE WILL APPLY TESTED CHEMICAL-KINETIC AND PHYSICAL MODELS. TO ASSURE SUCCESS OUR RESEARCH TEAM INCLUDES EXPERTS IN VENUS WEATHERING BASALT GEOCHEMISTRY EXPERIMENTAL PETROLOGY CHEMICAL DIFFUSION IN GLASSES AND ALL ANALYTICAL METHODS TO BE USED.