Science ObjectDigital resources are stored online in your NSTA Library.
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between NASA and NSTA, is the third of five Science Objects in the Universe SciPack. It explores the life cycle of stars and the variables that determine eventual characteristics of stars. The formation of a star begins with an immense cloud, containing molecules of the lightest elements, collapses under the influence of gravity. The molecules in the cloud heat (up as the cloud becomes more dense) until light elements consistently fuse into heavier ones, producing large amounts of energy. Eventually, the most massive of stars explode, producing new clouds that contain heavier elements. These new clouds of material set the stage for the formation of other stars and planets, in a cycle that repeatedly continues even today. The speed of this process and ultimate fate of a star depends primarily on its initial mass. Stars can differ from each other in size, temperature, and age, but they all behave according to the same physical principles.