For hundreds of years, people have wondered if there is life on other planets. Are humans on Earth alone in the universe, or could there be others out in space?
Until recently, humans could only speculate about the existence of life on other planets or in other galaxies. Today, however, technological advances are allowing us to actively search for signs of extra-terrestrial life.
The search for extra-terrestrial intelligence, or SETI, as it is more commonly known, uses a number of highly specialized tools, from computers to telescopes. Researchers use this equipment to scan space for any sign of extra-terrestrial intelligence, including radio transmission.
Of course, there are a number of challenges that are associated with the search for extra-terrestrial intelligence. One of the biggest challenges that SETI researchers face is figuring out how to search for transmissions, as the direction, spectrum and method of communication are all unknown.
There are a number of SETI projects, each of which must make assumptions about how extra-terrestrials will communicate. In this section, we’ll discuss the various SETI projects that are currently being conducted. We’ll discuss the equipment that is used for each project as well as the information that each project has gathered.
SETI@home is a popular SETI project that was launched by the University of California at Berkeley in May 1999. The project’s goal is to detect life in outer space. To this end, the project uses a “virtual supercomputer,” or a huge collection of Internet-connected computers. These computers are able to analyze data collected by telescopes.
When people join the SETI@home project, they agree to let researchers use their computers when they aren’t using it. According to the SETI@home Web site, researchers are able to do this via a screen saver that collects data from the Internet, analyzes the data and then submits it back to the researchers. When you need to use your computer, the screen saver disappears and only restarts its work once you are finished with your work.
What’s great is that anyone with an Internet-connected computer can take part in SETI@home!
SERENDIP, or Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations, is another SETI project that is sponsored by the University of California at Berkeley. Rather than using its own observation program, SERENDIP “piggy-backs” on a telescope, gathering deep space radio telescope data while astronomers use the telescope for other purposes.
Currently, SERENDIP is piggybacking on the largest telescope in the world, the 1,000-foot satellite dish at the Arecibo Observatory in Puerto Rico.
Interestingly, the hardware that collects data for the SERENDIP project also collects the data that is used for the SETI@home project.
ALLEN TELESCOPE ARRAY
The Allen Telescope Array aims to move the search for extra-terrestrial intelligence forward through the construction of 350 antennas. The end result will produce an instrument that is able to collect more data than a 328-foot telescope.
In 2007, the first phase of the Allen Telescope Array was complete with the 42 working antennas.