The Harvard-Smithsonian Center for Astrophysics and NASA's Office of Space Science jointly created this beautiful Web site for scientists, teachers, and students alike. The site is an excellent starting point for anyone interested in learning about the universe and features research, interviews, images, and an idea exchange forum on a wide range of topics related to the structure and evolution of the universe.

The physicists and astronomers who worked on the High-Z Supernova Search Team and the Supernova Cosmology Project are the ones who determined that the universe is expanding at an accelerating rate. These sites explain the project, named the "Science Magazine Breakthrough of the Year" in 1998, bringing it to life with images from the Hubble Space Telescope. To find out more about the project and the scientists involved, check out these two sites.

The Sloan Digital Sky Survey aims to systematically map one quarter of the entire sky, producing a detailed image and determining the positions of over 100 million celestial objects. The data and images from this ambitious work-in-progress, which recently located the most distant object ever observed, are available and regularly updated on the SDSS Web site.

VLT, the "Very Large Telescope" operated by the European Southern Observatory (ESO) in Atacama, Chile, is the world's most advanced optical telescope. The stunning photographs taken through VLT's lens are archived and updated at this ESO Web site.

Maintained by NASA's Goddard Space Flight Center, this Web site may be the only place where you'll find Generation-X defined as "a future ultra-large-aperture x-ray telescope intended to observe the x-ray universe." GSFC's site is a universe unto itself, loaded with detailed data archives, documents and papers, image libraries, and links to other sites dealing with space.

Though the ADC, also run by NASA's Goddard Space Center, functions primarily as an archive and distribution center of data that have been published by professional astronomers, there is plenty of information at this site that will be useful and comprehensible to the astronomy novice or hobbyist. If, for example, you're interested in pinpointing the 20 nearest stars or the 100 brightest stars the next time you look up at night, this site can show you how.

This book offers a clear and easily digestible explanation of how recent evidence that the universe is expanding at an accelerated rate is impacting cosmology. It also covers a range of topics relating to astrophysics, including a more in-depth description of supernovae than described in Birth of a Supernova.

Why did Einstein call his cosmological constant his biggest blunder? Find out in this comprehensive biography. In addition to providing an intimate portrayal of the 20th century's greatest scientist, the author makes accessible some of the great thinker's theories and experiments.

A fine introduction to cosmology and astrophysics, this book also tells the story of the astronomers who have discovered that the expansion of the universe is accelerating and the consequences of these findings. It also reveals how tentative these findings are.

A clear and comprehensive account of how we know what we know in the field of cosmology.

This article profiles Wendy Freedman, a cosmologist who finds herself at the center of the raging debate about how old and big the cosmos is and how fast it is expanding.