Authored by Nick Strobel, this chapter covers the characteristics of other normal galaxies, active galaxies, and finding distances to other galaxies, including the distance-scale ladder. It also includes large-scale...

This website, by Caltech astronomer Mike Brown, presents information on Sedna, an object believed to be from the Oort cloud. The site includes a description of the Oort cloud, a history of Sedna's discovery, and a...