If it's just us, it's a terrible waste of space.

 "There are countless suns and countless earths all rotating around their suns in exactly the same way as the seven planets of our system. We see only the suns because they are the largest bodies and are luminous, but their planets remain invisible to us because they are smaller and non-luminous. The countless worlds in the universe are no worse and no less inhabited than our Earth."

Have we heard from ET? Here's what the SETI Institute says in answer to that question:

"No SETI search has yet received a confirmed, extraterrestrial signal. If we had, you would know about it. There is no policy of secrecy, and no way to enforce it even if there were (Whenever Project Phoenix has a signal that looks interesting for even a few hours, the newspapers start ringing our phones!).

"In the past, there were several unexplained and intriguing signals detected in SETI experiments. Perhaps the most famous of these was the "Wow" signal picked up at the Ohio State Radio Observatory in 1977. However, none of these signals was ever detected again, and for scientists that's not good enough to claim success and boogie off to Stockholm to collect a Nobel Prize. You wouldn't believe cold fusion unless researchers other than the discoverers could duplicate it in their labs. The same is true of extraterrestrial signals: they are credible only when they can be found more than once.

"When will success occur? No one knows. It could happen tomorrow, or it could take many years. Maybe it will never occur. But the only way to find out is to do the experiment."

To learn more about SETI science, we recommend you visit the following reputable sources:

Harvard SETI: Operated by the Harvard-Smithsonian Center for Astrophysics, the telescope is located on Oak Ridge, Massachusetts, about an hour from Boston in apple orchard country. In 1983 the then-retired telescope became dedicated to SETI work. Among the efforts here is the restoration of a 25-meter (84-foot) radio telescope for use in the Billion Channel Extraterrestrial Assay (BETA). The big dish (shown at left with a six-year-old for scale) suffered damage to its half-century-old drive mechanicals in a 1999 storm. Its main gearbox was replaced as a part of the repair in July 2000. It was expected to be back in operation early in 2002. Not far away a new observatory is being built for an optical SETI effort. The 72-inch telescope will look for light signals of intelligent origin instead of radio signals -- the currently favored SETI approach. Read more at their Web site: http://seti.harvard.edu/seti

SETI@home is a scientific experiment that uses Internet-connected computers in the Search for Extraterrestrial Intelligence (SETI). Although the effort now has a surplus of volunteers, you can participate by running a free program. The program will analyze radio signals received at the Arecibo radio telescope for artificially-generated patterns Not Of This Earth. Visit their Web site and learn about this pioneering distributed computing project and how the search is going! http://setiathome.ssl.berkeley.edu

The SETI Institute: The mission of the SETI Institute is to explore and explain the nature, distribution and prevalence of life in the universe. Less well-known than the SETI@home project, the SETI Institute pursues a more direct approach to the search. With a staff of professional astronomers and technicians, the Institute runs real-time searches for E.T.'s radio signals from some of the world's largest radio telescope facilities. It is presently developing its own radio telescope, the Allen Telescope Array, so that SETI can have full-time access to a world-class instrument of its own. How can you help? Become a member and support with your cash donations and interest. http://www.seti-inst.edu

The Planetary Society was founded in 1980 by Carl Sagan, Bruce Murray, and Louis Friedman to encourage the exploration of our solar system and the search for extraterrestrial life. The Society is a nonprofit, nongovernmental organization, funded by dues and donations from individuals around the world. With more than 100,000 members from over 140 countries, they are the largest space interest group on Earth. Membership is open to all people interested in their mission. Through funding and advocacy, The Society supports SETI research including the Harvard efforts listed above. http://planetary.org