When viewing objects of different colors, you might notice that some appear brighter than others. This is because light is reflected differently from various surfaces, depending on their physical properties. The word albedo is used to describe how reflective a surface is. The Earth-atmosphere has a combined albedo of about 30%, a number that is highly dependent on local surface makeup, ground cover, angle of incidence, and cloud distribution (Budikova and Hogan 2010). Begin the series of activities described here using the information provided in this background to discuss the very general concept and definition of albedo.