target material can be determined and even extremely low concentrations (20 µg/kg) of impurities detected. Furthermore, because the sputtering continually etches deeper into the sample, concentration profiles as a function of depth can be measured. In space Sputtering is one of the forms of space weathering, a process that changes the physical and chemical properties of airless bodies, such as asteroids and the Moon. On icy moons, especially Europa, sputtering of photolyzed water from the surface leads to net loss of hydrogen and accumulation of oxygen-rich materials that may be important for life. Sputtering is also one of the possible ways that Mars has lost most of its atmosphere and that Mercury continually replenishes its tenuous surface-bounded exosphere. References External links Thin Film Evaporation Guide What is Sputtering? - an introduction with animations Sputtering Basics - animated film of a sputtering process Free molecular dynamics simulation program (Kalypso) capable of modeling sputtering American Vacuum Society short courses on thin film deposition (The original paper on Kaufman sputter sources.) Coatings Materials science Thin film deposition Surface science