The SETI@home, SERENDIP, SEVENDIP, Astropulse, and SPOCK SETI Programs ‘Dan Werthimer, Dave Anderson, Jeff Cobb, Paul Demorest, Eric Korpela, Cecile Kim, Geoff Marcy University of California, Berkeley http://seti.berkeley.edu/

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NOT FUNDED 1

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NOT FUNDED 1

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NOT FUNDED 1

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Porno in space: FUNDED! 1

Drake Equation N=R fs fp ne fl fi fc L N = number of communicating civilizations in our galaxy

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Planet Detection

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First Radio SETI Nikola Tesla (1899) Guglielmo Marconi (1920) Announces “coherent signals from Mars” Guglielmo Marconi (1920) Strange signals from ET Frank Drake (1960) Project Ozma one channel, 1420-1420.4 MHz

Signal Types 1. Artifact (radio, radar, ~TV, ????) 2. Deliberate (easy to decode, pictures, language lessons) First civilization we contact is likely to be a billion years ahead of us.

Targeted Search Strategy: Project Phoenix - Seti Institute Sky Survey Strategy: Serendip, SETI@home - UC Berkeley Beta - Harvard Southern Serendip - Australia Meta II - Argentina Seti Italia - Medicina Obser.

Quick History of Berkeley SETI Radio SETI SERENDIP Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations SERENDIP I-III (1979-1997) SERENDIP IV (1997-) SERENDIP V (2004-)

The Berkeley Radio SETI Family Tree SERENDIP SERENDIP II OSU SERENDIP III SETI Italia SETI@home Data Recorder SETI@home Clients SERENDIP IV Southern SERENDIP SETHI@Berkeley HI Survey AstroPulse Pulse Survey SETI@home II Data Recorder SETI@home II Clients SERENDIP V

SETI Programs at the University of California

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SERENDIP IV 168M channels 100 MHz Band centered on 1420 MHz Photos Courtesy NAIC Arecibo Observatory, a facility of the NSF 168M channels 100 MHz Band centered on 1420 MHz Carriage House 1 line feed Operating since 1997

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Why SETI@home? Coherent Doppler drift correction Narrower Channel Width->Higher Sensitivity Variable bandwidth/time resolution Search for multiple signal types Gaussian beam fitting Search for repeating pulses Problem: Requires TFLOP/s processing power. Solution: Distributed Computing

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The SETI@home Client

SETI@home Statistics TOTAL RATE

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Structure of SETI@home Tapes from Arecibo Online Science Database 3.8 Million Volunteers The Internet Work Unit Storage Data splitters Volunteer Statistics Master Result Verification Candidate Identification Web Server Data Server

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The Input and Output 1 Work-Unit=9.8 kHz x 220 samples (107 sec.) 256 Workunits across 2.5 MHz band centered on 1420.0 MHz. Workunits overlap in time by ~25 sec. Each workunit sent to multiple computers for result verification Typically 4 TFLOP/workunit. Output=Typically ~5 potential signals.

Spikes Power distribution in the Fourier transformed data is exponential if no RFI. SPIKE: Any bin in the spectrum above 22X the mean power (7.8x10-25 W/m2)

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Gaussians Weighted 2 fit to beam profile (vs time). Gaussian must exceed a power and 2 threshold Score inversely proportional to probability of arising due to noise Sensitivity 8.4x10-25 W/m2

Triplets Three evenly spaced spikes above 7.75X the mean power. (5.3X10-25 W/m2)

Pulses Modified Fast folding algorithm w/ dynamic threshold Logarithmically spaced periods from 3ms to 35s Sensitivity as low as 10-26 J/m2

Candidate Identification Candidate: A signal or group of signals Within a positional window (~1 beamwidth typ.) Within a frequency window (variable) Above a score or power threshold (variable) With time separation » typical transient RFI timescale Score: Relative ranking of a candidate’s probability of arising due to random noise. Should be independent of signal type Can also include probability of coincidence /w celestial objects

Gaussian Candidates

AstroPulse Sky survey Good time resolution DM range Sensitivity Covers decs 0 to 30 ~3 years of data recorded so far. Good time resolution Sensitive to 0.4 µs radio pulses at 21 cm DM range -100 to +100 pc/cm3 Sensitivity 10-18 W/m2 peak (Coherent de-dispersion)

Pulsed vs. CW Concentrating power into short bursts can be more efficient than a “constantly on” transmitter. Pulsed signals can be easier to see above background noise.

Dispersion … eventually becoming very weak. However, we can correct for dispersion ...

AstroPulse Only ~1.5 searches for single pulses on µs timescale before (O’Sullivan, Phinney) Pulsar searches: ms time scales, folded SETI@home: 0.8 ms single pulses. With interesting astrophysics as well as SETI applications. Evaporating primordial black holes? Pulsars, Other astrophysical exotica?

Conclusion: We need more computers! Computation … but it takes a lot of CPU time! To search DMs up to 100 pc/cm3 in real time, we need about 500 GigaFLOPs. (This would take ~1000 years of your PC working full time) Conclusion: We need more computers!

BOINC Berkeley Open Infrastructure for Network Computing General-purpose distributed computing framework. Open source. Will make distributed computing accessible to those who need it. (Starting from scratch is hard!)

AstroPulse/BOINC AstroPulse will be the first to use BOINC. It is a good “beta-test” application: Simple data analysis/reduction. “Only” needs a few thousand computers. Other projects which plan to use BOINC: SETI@home II Global climate modeling/prediction (Oxford)

AstroPulse Testing Sample batch of data run through shows expected noise characteristics, and little else … … so (hopefully) little RFI contamination for this type of signal.

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HI Column Density

OPTICAL SETI OPTICAL PULSE SEARCH Pulsed laser power output continues to grow. Petawatt pulses achieved at Livermore Labs. (Mjoule in 1nS) can detect at earth technology at 1Kpc little background noise, even from bright stars in whole visible band

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OSETI Detector 3-Photomultiplier fast coincidence detector Sensitive to 1ns pulses Low background False alarm rate: 1 per 300 hours (10-6 Hz) Double false alarm rate: 1 per 600 years! Good sensitivity 10-8 W/m2 peak 10-19 W/m2 average

Optical SETI Uses Leuschner Observatory (UCB) Targeted Search Automated 0.8m telescope Targeted Search Nearby F,G,K,M stars ~2,000 stars observed so far Soon to include galaxies

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Amy Reines and Geoff Marcy 47.jpg

10-meter Keck Telescope Survey: 650 F8 – M5 V, IV Hipparcos V < 8.5 B-V > 0.55 (F8V) Sep > 2 arcsec Age > 2 Gyr

Doppler Instruments Echelle Spectrometer Resolution: 60,000 Iodine Abs. Cell. Superimpose I2 lines Wavelength Calib.

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Piggyback ALFA Sky Survey SETI Instruments Dedicated spectrometer (SERENDIP V) 300 MHz bandwidth, 2 pols, 7 beams 5 * 109 channels, 0.8 Hz resolution SETI@home II data recorder 10 MHz, 1 pol, 7 beams Steps across 300 MHz band

Piggyback ALFA Sky Survey Improved sensitivity Tsys, integration time Uniform sky sampling galactic plane concentration Multibeam RFI rejection Larger Bandwidth

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Our Generous Sponsors The Planetary Society The University of California Sun Microsystems Friends of SETI@home Network Appliance Fujifilm IBM Quantum HP Xilinx The SETI Institute Informix EDT Netscreen Intel O’Reilly & Associates SpaceSounds Dillon Engineering NAIC, Arecibo Observatory ~4 million volunteers Maybe, someday, the U.S. Government

SETI HAIKU

Seti.berkeley.edu