Lick Observatory Optical SETI: Targeted Search and New Directions

Since the first search for radio signals from technological civilizations in the vicinity of nearby stars by Drake [1961] over four decades ago, there have been almost 100 SETI search projects published in the literature [Tarter, 2001], and undoubtedly many other unpublished, unsuccessful efforts as well. Media fascination with SETI, and its relative longevity, incline the general public to believe that observational exploration is a continuous enterprise, which has already surveyed much of the universe. In truth, the observational efforts to date, as enterprising and energetic as they have sometimes been, have hardly begun to sample the multi-dimensional phase space that may contain evidence of distant technologies. This paper provides a brief review of historical efforts, and highlights the exciting opportunities (and challenges) offered by dedicated SETI observing facilities now under construction. Far from being discouraged by decades of negative results, SETI researchers are eager for a new epoch of exploration with tools optimized for the task. Radio science has played, and will continue to play, a major role in attempts to answer the ancient question "Are we alone?"

Cornell University - arXiv, 2021

For more than 60 years, the predominant SETI search paradigm has entailed the observation of stars in an effort to detect alien electromagnetic signals that deliberately target Earth. However, this strategy is fraught with challenges when examined from ET's perspective. Astronomical, physiological, psychological, and intellectual problems are enumerated. Consequently, ET is likely to attempt a different strategy in order to best establish communications. It will send physical AI robotic probes that would be linked together by a vast interstellar network of communications nodes. This strategy would solve most or all problems associated with interstellar signaling.

1996

Key Words exobiology, astrobiology, bioastronomy, optical SETI, life in the universe s Abstract The search for evidence of extraterrestrial intelligence is placed in the broader astronomical context of the search for extrasolar planets and biomarkers of primitive life elsewhere in the universe. A decision tree of possible search strategies is presented as well as a brief history of the search for extraterrestrial intelligence (SETI) projects since 1960. The characteristics of 14 SETI projects currently operating on telescopes are discussed and compared using one of many possible figures of merit. Plans for SETI searches in the immediate and more distant future are outlined. Plans for success, the significance of null results, and some opinions on deliberate transmission of signals (as well as listening) are also included. SETI results to date are negative, but in reality, not much searching has yet been done.

SPIE Proceedings, 2011

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).

2016

Searches for extra-terrestrial intelligence (SETI) using large survey data often look for possible signatures of astroengineering. We propose to search for physically impossible effects caused by highly advanced technology, by carrying out a search for disappearing galaxies and Milky Way stars. We select ∼ 10 million objects from USNO-B1.0 with low proper motion (μ < 20 milli arcseconds / year) imaged on the sky in two epochs. We search for objects not found at the expected positions in the Sloan Digital Sky Survey (SDSS) by visually examining images of ∼ 290 000 USNO-B1.0 objects with no counterpart in the SDSS. We identify some spurious targets in the USNO-B1.0. We find one candidate of interest for follow-up photometry, although it is very uncertain. If the candidate eventually is found, it defines the probability of observing a disappearing-object event the last decade to less than one in one million in the given samples. Nevertheless, since the complete USNO-B1.0 dataset is ...

2015

The present SETI (Search for Extraterrestrial Intelligence) Project is devoted to the search for signals coming from technological civilizations living in other planets. Due to their capability to cross efficiently the interstellar medium (Cocconi and Morrison, 1959), radio frequencies have been chosen as the best method to receive and send communications from/to ET civilizations. This project is operational since a few decades and it is generally named Microwave Observing Project (MOP). The typically used frequency window ranges from 1 to 10 GHz. The goal of this investigation is to search for very narrow, possibly modulated radio signals, with a more or less marked polarization, which are presumably transmitted intentionally or unintentionally by emitters located on an extrasolar planet and characterized by a Doppler effect due to planet rotation and revolution around its star. The strategies which are currently adopted

The Astronomical Journal

As a major approach to looking for life beyond the Earth, the search for extraterrestrial intelligence (SETI) is committed to searching for technosignatures such as engineered radio signals that are indicative of technologically capable life. In this paper, we report a targeted SETI campaign employing an observation strategy named multibeam coincidence matching at the Five-hundred-meter Aperture Spherical radio Telescope toward 33 known exoplanet systems, searching for ETI narrowband drifting signals across 1.05–1.45 GHz in two orthogonal linear polarization directions separately. A signal at 1140.604 MHz detected from the observation toward Kepler-438 originally piqued our interest because its features are roughly consistent with assumed ETI technosignatures. However, evidences such as its polarization characteristics are able to eliminate the possibility of an extraterrestrial origin. Our observations achieve an unprecedented sensitivity because the minimum equivalent isotropic ra...

Research in Astronomy and Astrophysics, 2020

The discovery of ubiquitous habitable extrasolar planets, combined with revolutionary advances in instrumentation and observational capabilities, has ushered in a renaissance in the search for extraterrestrial intelligence (SETI). Large scale SETI activities are now underway at numerous international facilities. The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is the largest single-aperture radio telescope in the world, and is well positioned to conduct sensitive searches for radio emission indicative of exo-intelligence. SETI is one of the five key science goals specified in the original FAST project plan. A collaboration with the Breakthrough Listen Initiative was initiated in 2016 with a joint statement signed both by Dr. Jun Yan, the then director of National Astronomical Observatories, Chinese Academy of Sciences (NAOC), and Dr. Peter Worden, Chairman of the Breakthrough Prize Foundation. In this paper, we highlight some of the unique features of FAST that will ...

The Search for Extraterrestrial Intelligence (SETI) in the Optical Spectrum III, 2001

The Optical Search for Extraterrestrial Intelligence is now 40 years old. However, it was only during the closing years of the 20 th Century, after a 25-year hiatus, that the optical search has regained respectability in the SETI community at large. The quarter-of-a-century delay in American Optical SETI research was due to a historical accident and not for the lack of any enabling technology. This review paper describes aspects of past, present and future Optical SETI programs. Emphasis is placed on detecting fast, pulsed attention-getting laser beacon signals rather than monochromatic, continuous wave beacons. Some examples of commercial detection equipment that may be employed for either type of OSETI are given. It is expected that in time, some of the great telescopes of the world will be employed in this optical search for ETI signals. This may take the form of either dedicated observations or a type of Optical SERENDIP program, as had been done with Microwave SETI. There will also be large observatories built dedicated only to the optical search. Just as the microwave SETI@Home project has proved very popular with the public, the time has come for its optical equivalent. This paper also speculates on the eventual need to move Optical SETI observatories into space with high altitude balloons and space-based telescopes. It is expected that by the end of the first decade of the Third Millennium, the electromagnetic search for extraterrestrial intelligence on planet Earth will be dominated by SETI of the optical kind.

1. The SETI Project and its restrictions The present SETI (Search for Extraterrestrial Intelligence) Project is devoted to the search for signals coming from technological civilizations living in other planets. Due to their capability to cross efficiently the interstellar medium (Cocconi and Morrison, 1959), radio frequencies have been chosen as the best method to receive and send communications from/to ET civilizations. This project is operational since a few decades and it is generally named Microwave Observing Project (MOP). The typically used frequency window ranges from 1 to 10 GHz. The goal of this investigation is to search for very narrow, possibly modulated radio signals, with a more or less marked polarization, which are presumably transmitted intentionally or unintentionally by emitters located on an extrasolar planet and characterized by a Doppler effect due to planet rotation and revolution around its star. The strategies which are currently adopted for this research ar...