Author: Monika Rap

This strange name stands for "Search for Extraterrestrial Intelligence". It is a scientific programme, whose goal is to contact alien civilizations. The search for extraterrestrial intelligence concerns listening to the various artifical space radio and light signals that have not been produced by our probes and other devices.

However, our galaxy is about 100,000 light-years wide and contains 400 billion stars. The observations of all of them would take hundreds of years. There comes the idea of four main assumptions of SETI:

1. Almost all forms of life in our galaxy are built of carbon. This assumption is pretty well proved, because the carbon is the only chemical element able to create complex structures on its own.
2. The existence of liquid water is necessary, because the water environment is the only that can support the metabolism of life.
3. The search process should concern only the stars similar to our Sun. Huge stars live too short even in order to form a planetary system, whereas too small ones provide too little energy and light.
4. The alien civilizations sent some signals that could be caught.

One of the most interesting projects, which probably stay connected with ATA (Alien Telescope Array) is SETI@home started in 1999. Its goal is to use the power of personal computers spread along the Internet. An ordinary user who wants to participate, downloads and installs a small programme that works in the backgrounds. It downloads the parts of the signal, does the analysis and sends back the results to the servers in Berkeley, where the laboratory of SETI is located. In November 2005 the project was moved to the Berkeley Open Infrastructure for Network Computing platform developed at the University in Berkeley. The platform allows to start many similar projects.

The SETI programme has been runing for 30 years so far, but this is relatively short period, when compared to the age of the galaxy. What is more, some of the goals may not be true. Although we have not found the aliens, the attempts to contact them are worth considering. The statistics supports us.

The photo of radiotelescopes available under Creative Commons Share Alike 2.0 license. The author: Hajor.