Find Aliens By Using Your Computer
SETI Scientific Experiment Using The Internet to Detect Signals
The acronym SETI stands for Search for Extraterrestrial Intelligence, and its purpose is to detect intelligent life outside of Earth by listening to radio signals from space received through radio telescopes. At the base of telescope are supercomputers which continually record data and send to astronomy labs throughout the world.
History of Project SETI
Prior to 1999, Project SETI only utilized supercomputers located at the base of the telescope for data analysis. These computers did not look for weak signals or certain ranges of signals due to the large amount of data processed.
In 1995, David Gedye headed up a project that looked into ways that all types of signals could be analyzed. It was determined that smaller computers connected through the Internet were able to analyze data the supercomputers were unable to handle. In 1999, project SETI@home was launched with an appeal for volunteers to install specialized software on their computers.
The Purpose of SETI@home
According to SETI, extraterrestrials communicate through signals on a very narrow frequency range or narrow bandwidth. This is because narrow frequency signals take less power to transmit. A narrow frequency range is also easier to weed out from the background noise. In addition, the signal is expected to be weak due to the distance it has to travel to reach the realm of the telescope on Earth.
By dividing up the data received by the radio telescope into smaller chunks, a network of home computers can continually analyze the results in order to find the specific frequency which may contain a signal from extraterrestrials in outer space.
How SETI@home Works
The Arecibo radio telescope in Puerto Rico transmits all data that has not been filtered to SETI@home. This data will contain signals from radar, microwave relay towers, and television stations. In turn, small chunks of data, called work units, are transmitted to a home computer for weeding out background noise and for finding unusual signals. Once the analysis is finished, the results are sent back to SETI@home. If a strong signal is detected by the screen saver, the SETI team is alerted.
How SETI@home Analyzes Data
Once the work unit is received by SETI@home, it is merged back into the database. Their computers pick up signals that have not been previously identified. The SETI@home team has a database of known radio-frequency interference (RFI) sources and the signal from a home computer is run through the database. If the signal from a home computer is identified as RFI, it is eliminated.
Unidentified signals are checked against another observation for the same part of the sky. If the signal is still not identified, it is observed again by the SETI@home team and other groups who use different telescopes and receivers to determine if the signal has been transmitted from an interstellar source.
If the signal is confirmed as interstellar, SETI@home will make an announcement to the astronomical community in an IAU (International Astronomical Union) telegram. The recipients of the telegram will be given the necessary information in order to conduct their observations. At this stage, it is still not certain if the signal is a result of an astronomical event or actually from an alien civilization.
Volunteering for SETI@home
Volunteers who wish to participate in the project can download BOINC software from the SETI@home website. The software installs a special screen saver on your computer that acts as a tuning device.
If a volunteer needs to use her computer, the screensaver will disappear and hold the data and resume the analysis after the volunteer allows her computer to go idle again. The supercomputer will send out another work unit for the computer to analyze when the volunteer chooses to allow another session. Volunteers control how often their computers connect to SETI@home.
Volunteers whose computers find an unidentified signal will be named as a co-discoverer along with the members of the SETI@home team.
Source
SETI@home - University of California, Berkeley
