|The greatest distance we have dealt with in these labs so far is the distance to the dwarf planet Eris. In terms of light travel time the distance from the Sun to Eris is about 9 light hours. No one really knows how to define the boundary of our Solar System but Eris may be representative of objects in the outermost parts. The next nearest major object is the star Proxima Centauri. In terms of light travel time Proxima Centauri is 4.3 light years away. Think about that a little bit. It takes light 9 hours to get from the Sun to Eris and 4.3 YEARS to get to the Sun's nearest neighbor.|
The purpose of this lab is to teach you how astronomers find distances to nearby stars. The specific method we will explore is called parallax. Parallax forms the basis for finding distances to most astronomical objects. You will learn how parallax is used through hands-on activities and you will apply what you have learned to determine distances to some objects.