What have we learned about the universe over the past four centuries? Visions of the Universe asks just that, looking deep into the past to bring a bit of this history to the general public. On the site, visitors can make their way through twelve exhibits, including Storms on the Sun and Journey To Mars. Each section features a detailed poster for classroom use, along with other activities and...

This Topic in Depth presents the science and research of galaxies. First, the University of Cambridge offers clear, logical descriptions and images of the Milky Way, spiral and elliptical galaxies, clusters, and dark matter of the Universe (1). Users can also find educational tutorials on many other cosmology topics. Next, the Space Telescope Science Institute's "Galaxies Galore, Games and More is...