This article describes one fifth grade's participation in in NASA's S'COOL (Students' Cloud Observations On-Line) Project, making cloud observations, reporting them online, exploring weather concepts, and gleaning some of the things involved in authentic scientific research. S?COOL is part of a real scientific study of the effect of clouds on Earth?s climate. Students from all over the world add to data collected by NASA's Earth-observing satellites. Matching student observations--called ground truth measurements--with satellite readings helps NASA verify and calibrate their data. When the orbital path of an Earth-observing satellite--either Aqua or Terra--is over your region of the world (about once a day), students record cloud observations. These observations include cloud level-- high, midlevel, or low; cloud type, such as cirrus, stratus, etc.; cloud cover, such as clear, partly cloudy, or overcast; and visual opacity--opaque, translucent, or transparent. Students may record some optional data, which includes such surface measurements as temperature, barometric pressure, and relative humidity. Readers will gather from the experiences of this class that this project is very adaptable and can be integrated into many subject areas and used throughout the school year at any grade level. Figure 1 provides an overview of cloud types.