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 fourth of five Science Objects in the Universe SciPack. It explores the more unknown parts of the universe beyond our solar system and provides an understanding of where and how we fit into the universe as a whole. Astronomers have carefully measured the changing positions of stars, leading them to believe that the Sun is located about half-way out from the center of a disk-shaped galaxy of stars, part of which can be seen as a glowing band of light that spans the sky on a very clear night. Although our Sun is a single star, most stars exist in systems of two or more stars orbiting around one another and are arranged in huge star clusters. Galaxies are isolated collections of billions of gravitationally bound stars and immense clouds of gas and dust. Galaxies are, in turn, grouped into galaxy clusters and super-clusters. The universe contains many billions of galaxies separated by immense distances of mostly empty space. Some of these distant galaxies are so far away that their light takes several billion years to reach Earth. This means that here on Earth we are seeing them as they were that long ago.