"It is fair to say that astronomy is still just about the only science in which the amateur can make valuable contributions today, and in which the work is welcomed by professionals..."
"The idea of life in outer space is a very old one, going back to the Greek philosophers. The existence of other inhabitable worlds and extraterrestrial life has for hundreds of years been one of the few very prime questions in science. Not only would their discovery provide a bonanza of new scientific information, it would provide great insights concerning the significance and destiny of humanity: Where did we come from, are we unique, what is our place in the cosmos, and what might our future be?" - Seth Shostak, Confessions of an Alien Hunter: A Scientist's Search for Extraterrestrial Intelligence
Google has collaborated with some of the world's largest observatories to allow users to experience space exploration from their computers. Use Google Sky to see everything from the positions of various constellations and planets to how our universe would look if viewed through different wavelengths.
An infared view of the constellation Leo on Google Sky
"The William N. Deramus III Cosmology Theater features some of the latest high-definition video projection technology. A 114" display screen with a 1080i* digital projector and a totally revamped and upgraded sound system provide the viewer with a stunning visual and sound experience. The theater currently features the ViewSpace program of the Space Telescope Science Institute."
At NASA's HubbleSite, you can view images and videos captured by the Hubble telescope, listen to Skywatch audio broadcasts and podcasts and talks on Hubble Hangouts, and even learn about the development of the Webb telescope, a "tennis-court sized" structure that will observe the cosmos while in orbit and a worthy successor to the Hubble.