Status of the UC-Berkeley SETI efforts

Abstract

We summarize radio and optical SETI programs based at the University of California, Berkeley.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 ongoing SERENDIP V.v sky survey searches for radio signals at the 300 meter Arecibo Observatory. The currently installed configuration supports 128 million channels over a 200 MHz bandwidth with ∼1.6 Hz spectral resolution. Frequency stepping allows the spectrometer to cover the full 300MHz band of the Arecibo L-band receivers. The final configuration will allow data from all 14 receivers in the Arecibo L-band Focal Array to be monitored simultaneously with over 1.8 billion channels.SETI@home uses the desktop computers of volunteers to analyze over 160 TB of data at taken at Arecibo. Over 6 million volunteers have run SETI@home during its 10 year history. The SETI@home sky survey is 10 times more sensitive than SERENDIP V.v 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 -100 Hz/s to +100 Hz/s. SETI@home is being expanded to analyze data collected during observations of Kepler objects of interest in May 2011.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 the amount of dispersion is unknown, Astropulse must search through 30,000 possible dispersions. Substantial computing power is required to conduct this search, so the project uses volunteers and their personal computers to carry out the computation (using distributed computing similar to SETI@home).

The Breakthrough Listen Search for Intelligent Life: 1.1–1.9 GHz Observations of 692 Nearby Stars

“…The potential spectral similarity between anthropogenic radio-frequency interference (RFI) and extraterrestrial technological transmissions brings additional complications. The sheer immensity of the parameter space that must be explored is a potential explanation to the absence of radio detections of extraterrestrial intelligence, despite numerous previous efforts (Verschuur 1973;Tarter et al 1980;Bowyer et al 1983Bowyer et al , 1995Horowitz et al 1986;Steffes & Deboer 1994;Mauersberger et al 1996;Backus 1998;Werthimer et al 2000;Korpela et al 2011;Siemion et al 2013;Harp et al 2016;Gray & Mooley 2017).…”

A Search for Laser Emission with Megawatt Thresholds from 5600 FGKM Stars

“…Commensal, beam-forming radio observations with the future MeerKAT array and the Square Kilometer Array, (Siemion et al 2014) would be 100x more sensitive to SETI radio signals than prior searches and would have the ability to survey millions of stars and galaxies limited by back-end compute power. The interest in optical and near-infrared extraterrestrial laser emission has spurred searches for pulses having duration as short as a nanosecond or displaying periodicities (Howard et al 2004(Howard et al , 2007Korpela et al 2011;Drake et al 2010;Mead 2013;Covault 2013;Leeb et al 2013;Gillon 2014;Wright et al 2014ab). …”

“…Cocconi & Morrison 1959;Drake 1961;Horowitz & Sagan (1993) ;Tarter 2001;Howard et al 2007;Hanna et al 2009;Siemion et al 2013;Wright et al 2014a;Wright et al 2016;Lacki 2016)). Searches have been conducted at radio wavelengths with Arecibo, Green Bank telescope, Parkes radio telescope, and the Allen telescope array (Drake 1961;Werthimer et al 2001;Korpela et al 2011;Siemion et al 2013, Tarter et al 2011, and Harp et al 2015. These searches targeted both stars and galaxies, and more recently stars harboring known exoplanets (Siemion et al 2013).…”

If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?

“…See Alcubierre (1994) for his paper describing the warp drive. 120 Pg 88 unrealistic features For details on the possibility of using wormholes for transport, see Krasnikov (2000). For details on Van Den Broeck's warp drive, see Van Den Broeck (1999).…”