Searching for ET with Help from Four Million Volunteers: The SETI@home, SERENDIP, SEVENDIP, ASTROPULSE and SPOCK Seti Programs

摘要

We summarize results from three radio and two optical SETI programs based at the University of California, Berkeley. The ongoing SERENDIP IV sky survey searches for radio signals at the 300 meter Arecibo Observatory. SERENDIP IV uses a 168 million channel spectrum analyzer and a dedicated receiver to take data 24 hours a day, year round. The sky survey covers a 100 MHz band centered at the 21 cm line (1420 MHz) and declinations from -2 to +38 degrees. SETI@home uses desktop computers of 5 million volunteers to analyze 50 Terabytes of at taken at Arecibo. The SETI@home sky survey is 10 times more sensitive than SERENDIP IV but it covers only a 2.5 MHz band, centered on 1420 MHz. SETI@home searches a much wider parameter space, including 14 octaves of signal bandwidth and 15 octaves of pulse period with Doppler drift corrections from -50 Hz/s to +50 Hz/s. SETI@home is the planet's largest supercomputer, averaging 45 Tflops. SETI@home participants have contributed over a million years of computing time so far. The SEVENDIP optical pulse search looks for ns time scale pulses at visible wavelengths. It utilizes an automated 30 inch telescope, three ultra fast photo multiplier tubes and a coincidence detector. The target list includes F,G,K and M stars, globular cluster and galaxies. The SPOCK optical SETI program searches for narrow band continuous signals using spectra taken by Marcy and his colleagues in their planet search at Keck observatory. The ASTROPULSE project is the first SETI search for μs time scale pulses in the radio spectrum. Because short pulses are dispersed by the interstellar medium, and amount of dispersion is unknown, ASTROPULSE must search through thousands of possible dispersions. Substantial computing power is required to conduct this search, so the project will use volunteers and their personal computers to carry out the computation (using distributed computing similar to SETI@home). The ASTROPULSE software is being tested now, and we hope to begin this search early next year.