Other
University of Leicester: Spiral Galaxies
Provides a general overview of spiral galaxies, including descriptions of the different classes of spiral galaxy.
PBS
Pbs Learning Media: Spin a Spiral Galaxy
This interactive activity from NOVA Online lets you spin a spiral galaxy, including our own Milky Way. It demonstrates that what you can learn from visible light observations of a galaxy is largely determined by the angle from which you...
California Institute of Technology
Spitzer Space Telescope: Our Galaxy's 'Twin'
This image, titled "Morphology of Our Galaxy's 'Twin'" features three individual pictures of a nearby spiral galaxy that closely resembles our own. The text under the image details various specifics about the picture.