Search For Extraterrestrial Intelligence Research Articles

Project Hephaistos – II. Dyson sphere candidates from Gaia DR3, 2MASS, and WISE

Abstract The search for extraterrestrial intelligence is currently being pursued using multiple techniques and in different wavelength bands. Dyson spheres, megastructures that could be constructed by advanced civilizations to harness the radiation energy of their host stars, represent a potential technosignature, that in principle may be hiding in public data already collected as part of large astronomical surveys. In this study, we present a comprehensive search for partial Dyson spheres by analyzing optical and infrared observations from Gaia, 2MASS, and WISE. We develop a pipeline that employs multiple filters to identify potential candidates and reject interlopers in a sample of five million objects, which incorporates a convolutional neural network to help identify confusion in WISE data. Finally, the pipeline identifies 7 candidates deserving of further analysis. All of these objects are M-dwarfs, for which astrophysical phenomena cannot easily account for the observed infrared excess emission.

Universidad del Atlántico Medio

The search for extraterrestrial intelligence on exoplanets is a rich field of conceptual exploration. Author introduces two definitions that could help to narrow down the possibilities that an extraterrestrial civilization may or may not have initiated exploration of its own star system and beyond. It is concluded that in some cases certain extraterrestrial civilizations may not be able to leave their home worlds before their biological extinction, purely because of physical limitations. Keywords: SETI, ETI, Exoplanets, Alien Civilizations, Alien Exploration

Research repertoires and boundary work in the search for extra-terrestrial intelligence (SETI)

ABSTRACT The idea of scouting the sky in search of extra-terrestrial signals (SETI) was first proposed in the late 1950s; soon afterwards, its scope was formalised in the so-called Drake Equation, a probabilistic argument to gauge the number of ‘civilisations’ capable of radio communication on the basis of astronomical, biological and cultural factors. Since then, radio telescopes around the world have been searching for an artificial signal from elsewhere in the universe, a sign of extraterrestrial communication. How have SETI practitioners claimed scientific legitimacy and epistemic authority over the search for extra-terrestrial life, a matter often regarded to be at the very periphery of science? And how have they succeeded (or failed) in maintaining them over time? The historical trajectory of SETI offers the opportunity to investigate how, over time, an interdisciplinary community coalesced around a research repertoire and navigated ebbs and flows of interest by rearticulating the methods and scope of their research. The ‘probability repertoire’ around which the SETI community coalesced is an evolving entity, entailing significant boundary work. As with every successful repertoire, it is a flexible but always entailing a recognisable alignment of material, social and epistemic components instrumental for a research community in gaining recognition and negotiating its epistemic positioning within the always shifting boundaries of science.

Deciding Technosignature Search Strategies: Multi-Criteria Fuzzy Logic to Find Extraterrestrial Intelligence

This study presents the implementation of Multi-Criteria Decision-Making (MCDM) methodologies, particularly the fuzzy technique for order of preference by similarity to ideal solution (TOPSIS), in prioritizing technosignatures (TSs) for the search for extraterrestrial intelligence (SETI). By incorporating expert opinions and weighted criteria based on the established Axes of Merit, our analysis offers insights into the relative importance of various TSs. Notably, radio and optical communications are emphasized, in contrast to dark side illumination and starshades in transit. We introduce a new axis, Scale Sensitivity, designed to assess the variability of TS metrics. A sensitivity analysis confirms the robustness of our approach. Our findings, especially the highlighted significance of artifacts orbiting Earth, the Moon, or the Sun, indicate a need to broaden evaluative criteria within SETI research. This suggests an enhancement of the Axes of Merit, with a focus on addressing the plausibility of TSs. As the quest to resolve the profound question of our solitude in the cosmos continues, SETI efforts would benefit from exploring innovative prioritization methodologies that effectively quantify TS search strategies.

Shuffled frog Leaping algorithm based circular patterns loaded ring shaped fractal antenna for multistandard wireless applications

This paper describes the design and experimental behavior of a 2nd iterated modified Square Ring Shaped Fractal Antenna (SRSFA). The radiator geometry consists of three symmetrical square-shaped rings loaded with circular patterns at the corners. The designed fractal patch is placed on a slot loaded ground structure. The electrical dimensions possessed by the realized structure are 0.15λ0 x 0.15λ0 x 0.080 λ0, and the whole antenna is implemented using FR4 substrate. In this design, transmission line width ‘WF’ and position ‘FP’ are optimized using Shuffled Frog Leaping Algorithm (SFLA) and Artificial Bee Colony (ABC) strategies. It has been examined that the optimized values of ‘WF’ and ‘FP’ using SFLA and ABC are 2.6 and 12.4 mm, and 3.2 and 15.9 mm, respectively. Results reveal that SFLA offers better solution quality and convergence speed than ABC. Further, experimental analysis has been demonstrated to effectively illustrate the recommended fractal approach. The equivalent circuit of the designed structure is implemented successfully. The conducted measurements show that for VSWR ≤ 2, the fabricated structure produces six resonance points with adorable S11 values. The resonances appear at 1.53 GHz (1.35–1.67 GHz), 4.30 GHz (4.20–4.40 GHz), 7.58 GHz (7.43–7.70 GHz), 11.35 GHz (10.37–11.58 GHz), 14.03 GHz (13.85–14.35 GHz), and 15.93 GHz (15.43–16.25 GHz). The examined −10 dB impedance bandwidth at the respective resonance points is 20.9 %, 4.6 %, 3.5 %, 11.3 %, 2.9 %, and 5.23 %. Healthy concordance is noticed among the experimental measurements and electromagnetic simulations. The demonstrated radiation patterns are arbitrary bidirectional/omnidirectional at the respective resonances with good stability. Additionally, the offered gain is within the range of 4.91–7.00 dB. Hence, by utilizing the above-mentioned approaches, miniaturization of 65 % has been achieved. Practical outcomes suggest that the introduced prototype exhibiting multiband behavior, can be effectively applied in Radio location, Radio astronomy, Long-range tracking, Weather location Broadcasting, Search for extra-terrestrial intelligence, Radar altimeters, High resolution mapping, Aeronavigation, and Miscellaneous Radars.

Psychological aspects in unidentified anomalous phenomena (UAP) witnesses

Abstract In this study, we surveyed a total of 245 people about unidentified anomalous phenomena (UAP), 93 who directly witnessed UAP. Paying special attention to the psychological impact of UAP, our study survey covered different aspects, including opinions on official UAP releases, the scientific approach to the phenomena and the search for extra-terrestrial intelligence. This study found that UAP had a clear psychological impact on witnesses, with a transformative effect, and a benign form of a non-pathological obsessive-like interest in the topic we defined as the UAP deep psychological engagement triad. This deep psychological engagement triad is characterized by UAP topic being present in a witness's mind daily, with a self-recognized interest and appreciation for the topic and a need to talk about UAP topic, not necessarily the event they experienced. UAP appear to have a very specific impact focused on extra-terrestrial aspects and the phenomena itself, which is experienced as a life-changing event by direct witnesses. These psychological aspects are quantitatively and qualitatively objectifiable, and further research is needed in this direction since all research efforts appear currently focused on the physical aspects of these phenomena.

Polarization Criterion in Targeted SETI Observation

In this paper, we propose a novel method for distinguishing extraterrestrial intelligence (ETI) signals from radio frequency interference (RFI) by leveraging polarization features. We exploit the sinusoidal variation of the linearly polarized components of Stokes parameters with the parallactic angle as a characteristic signature of ETI signals, while such linearly polarized components remain relatively stable for terrestrial RFI. Typically, a minimum of 4–8 hr of observation time is required to detect these sinusoidal variations. The polarization approach in the search for extraterrestrial intelligence also enables us to study the radio stellar bursts emitted by M-type stars as ancillary science, which is relevant to assessing the habitability of exoplanets. Compared to the frequency drift method, the polarization method effectively reduces the required observation time for signal identification while improving the signal identification process.

Children of time: the geological recency of intelligence and its implications for SETI

Abstract Of all species on Earth, only one – Homo sapiens – has developed a technological civilization. As a consequence, estimates of the number of similar civilizations beyond Earth often treat the emergence of human-like intelligence or ‘sophonce’ as an evolutionary unicum: a contingent event unlikely to repeat itself even in biospheres harbouring complex brains, tool use, socially transmitted behaviours and high general intelligence. Here, attention is drawn to the unexpected recency and temporal clustering of these evolutionary preconditions to sophonce, which are shown to be confined to the last ≤102 million years. I argue that this pattern can be explained by the exponential biotic diversification dynamics suggested by the fossil record, which translated into a nonlinearly expanding range of cognitive and behavioural outcomes over the course of Earth's history. As a result, the probability of sophonce arising out of a buildup of its enabling preconditions has been escalating throughout the Phanerozoic. The implications for the Silurian hypothesis and the search for extraterrestrial intelligence (SETI) are discussed. I conclude that the transition from animal-grade multicellularity to sophonce is likely not a rate-limiting step in the evolution of extraterrestrial technological intelligences, and that while H. sapiens is probably the first sophont to evolve on Earth, on macroevolutionary grounds it is unlikely to be the last.

A Solution to Continuous RFI in Narrowband Radio SETI with FAST: The MultiBeam Point-source Scanning Strategy

Narrowband radio search for extraterrestrial intelligence (SETI) in the 21st century suffers severely from radio frequency interference (RFI), resulting in a high number of false positives, and it could be the major reason why we have not yet received any messages from space. We thereby propose a novel observation strategy, called MultiBeam Point-source Scanning (MBPS), to revolutionize the way RFI is identified in narrowband radio SETI and provide a prominent solution to the current situation. The MBPS strategy is a simple yet powerful method that sequentially scans over the target star with different beams of a telescope, creating real-time references in the time domain for cross-verification and thus potentially identifying all continuous RFI with a level of certainty never achieved in any previous attempts. By applying the MBPS strategy during the observation of TRAPPIST-1 with the Five-hundred-meter Aperture Spherical radio Telescope, we successfully identified all 6972 received signals as RFI using the solid criteria introduced by the MBPS strategy. Therefore, we present the MBPS strategy as a promising tool that should bring us much closer to the first discovery of a genuine galactic greeting.

The Most Sensitive SETI Observations Toward Barnard's Star with FAST

Search for extraterrestrial intelligence (SETI) has been mainly focused on nearby stars and their planets in recent years. Barnard’s star is the second closest star system to the Sun and the closest star in the Five-hundred-meter Aperture Spherical radio Telescope (FAST) observable sky which makes the minimum Equivalent Isotropic Radiated Power required for a hypothetical radio transmitter from Barnard’s star to be detected by FAST telescope a mere 4.36 × 108 W. In this paper, we present the FAST telescope as the most sensitive instrument for radio SETI observations toward nearby star systems and conduct a series of observations to Barnard’s star (GJ 699). By applying the multibeam coincidence matching strategy on the FAST telescope, we search for narrow-band signals (∼Hz) in the frequency range of 1.05–1.45 GHz, and two orthogonal linear polarization directions are recorded. Despite finding no evidence of radio technosignatures in our series of observations, we have developed predictions regarding the hypothetical extraterrestrial intelligence signal originating from Barnard’s star. These predictions are based on the star’s physical properties and our observation strategy.

Planetary biotechnospheres, biotechnosignatures and the search for extraterrestrial intelligence

AbstractThe concept of planetary intelligence as collective intelligence is used to consider possible evolutionary paths of biotechnospheres that emerge on the intersection of the technosphere with the biosphere and support coupling of the technosphere with the biosphere, thus affecting planetary evolution. In mature biotechnospheres, the intelligence of technologies and the intelligence of life forms, including engineered life forms, could act in concert to perform various tasks (e.g. monitoring planetary biospheres and environments; restoring planetary environments and biodiversity; steading planetary environments; providing support for space missions; terraforming cosmic objects). Space exploration can expand biotechnospheres beyond planets and create cosmic ecosystems encompassing planets and other cosmic objects; biotechnospheres, spacecraft and the environments of near-planetary, interplanetary space or interstellar space. Humankind, other civilizations or their intelligent machines may produce biotechnosignatures (i.e. observables and artefacts of biotechnospheres) in the Solar System and beyond. I propose ten possible biotechnosignatures and strategies for the search for these biotechnosignatures in situ and over interstellar distances. For example, if a non-human advanced civilization existed and built biotechnospheres on Earth in the past, its biotechnospheres could use engineered bacteria and the descendants of that bacteria could currently exist on Earth and have properties pertaining to the functions of the ancient bacteria in the biotechnospheres (such properties are proposed and discussed); intelligent technologies created by the ancient civilization could migrate to the Solar System's outer regions (possible scenarios of their migration and their technosignatures and biotechnosignatures are discussed); these two scenarios are described as the Cosmic Descendants hypothesis. Interstellar asteroids, free-floating planets, spacecraft and objects gravitationally bound to flyby stars might carry extraterrestrial biotechnospheres and pass through the Solar System. In connection to the fate of post-main-sequence stars and their Oort clouds, the probability for interstellar asteroids to carry biotechnospheres or to be interstellar spacecraft is estimated as very low.

A Search for Extraterrestrial Technosignatures in Archival FAST Survey Data Using a New Procedure

The search for extraterrestrial intelligence (SETI) commensal surveys aim to scan the sky to find possible technosignatures from an extraterrestrial intelligence (ETI). The mitigation of radio frequency interference (RFI) is an important step, especially for the most sensitive Five-hundred-meter Aperture Spherical radio Telescope (FAST), which can detect more weak RFI. In this paper, we propose several new techniques for RFI mitigation and use our procedure to search for ETI signals from the archival data of FAST’s first SETI commensal survey. We detect the persistent narrowband RFI by setting a threshold of the signals’ sky separation and detect the drifting RFI (and potentially other types of RFI) using the Hough transform. We also use the clustering algorithms to remove more RFI and select candidates. The results of our procedure are compared to the earlier work on the same FAST data. We find that our methods, though relatively simpler in computation, remove more RFI (99.9912% compared to 99.9063% in the earlier work) but preserve the simulated ETI signals, except for those (5.1%) severely affected by the RFI. We also report more interesting candidate signals, about a dozen of which are new candidates that were not previously reported. In addition, we find that the proposed Hough transform method, with suitable parameters, also has the potential to remove the broadband RFI. We conclude that our methods can effectively remove the vast majority of the RFI while preserving and finding the candidate signals that we are interested in.

A sign in space: An interdisciplinary exploration of the potential reception of an extraterrestrial signal

A Sign in Space is an interdisciplinary project by media artist Daniela de Paulis, in collaboration with the Green Bank Observatory, the National Institute for Astrophysics, the SETI Institute and the European Space Agency.The project consists in transmitting a simulated extraterrestrial message as part of a live performance, using an ESA spacecraft as celestial source. The objective of the project is to involve the worldwide search for extraterrestrial intelligence (SETI) community, professionals from different fields and the broader public in the reception, decoding and interpretation of the message. This process will require global cooperation, bridging a conversation around the topics of SETI, space research and society, across multiple cultures and fields of expertise.

Affordances in outer space: Forms of life, material engagement, and meaning within space exploration and SETI

Exploration of outer space is a mesmerizing and thought-provoking endeavor. The fascination about what may be out there is only matched by asking who might be out there. Exopsychology is concerned about how humans think about extraterrestrials, but also how extraterrestrials may think, feel, and behave. It strives to find generalizable psychological theories to enrich and extend the Search for Extraterrestrial Intelligence (SETI). Producing technosignatures requires that a species skillfully realizes the relevant possibilities for action, which the environment offers in all its socio-material richness. These possibilities are called affordances. They are not fixed but relational to individual and collective available abilities and customs. We apply an affordance perspective to specify the relation between information processing, body, environment, and material engagement in the context of space exploration and SETI. In this way, we can uncover aspects of the psychological configurations that SETI requires from its extraterrestrial targets, but which are also critical to the human practice of space exploration. Moreover, we elaborate on arguments against employing the concept of “intelligence” in SETI. A successful first contact requires a mutual attunement to species-typical diachronic backdrops, which constitute meaning. One possibility for a meaningful message form and content is the reference to the material environment and its respective engagement. Meaningfulness of affordances is conserved in a form of life and transmitted via social interaction. Considering affordances within SETI fosters an understanding of how the thinking, feeling, and behavior of life forms in the Universe emerge in relation to their socio-material environment.

An interferometric SETI observation of Kepler-111 b

ABSTRACT The application of very long baseline interferometry (VLBI) to the search for extraterrestrial intelligence (SETI) has been limited to date, despite the technique offering many advantages over traditional single-dish SETI observations. In order to further develop interferometry for SETI, we used the European VLBI network (EVN) at 21 cm to observe potential secondary phase calibrators in the Kepler field. Unfortunately, no secondary calibrators were detected. However, a VLBA primary calibrator in the field, J1926+4441, offset only ∼1.88 arcmin from a nearby exoplanet Kepler-111 b, was correlated with high temporal $\left(0.25 \, \rm {s}\right)$ and spectral $\left(16384 \times 488\, \rm {Hz \ channels}\right)$ resolution. During the analysis of the high-resolution data, we identified a spectral feature that was present in both the auto and cross-correlation data with a central frequency of 1420.424 ± 0.0002 MHz and a width of 0.25 MHz. We demonstrate that the feature in the cross-correlations is an artefact in the data, associated with a significant increase in each telescope’s noise figure due to the presence of H i in the beam. This would typically go unnoticed in data correlated with standard spectral resolution. We flag (excluded from the subsequent analysis) these channels and phase rotate the data to the location of Kepler-111 b aided by the Gaia catalogue and search for signals with $\rm {SNR}\gt 7$ . At the time of our observations, we detect no transmitters with an equivalent isotropically radiated power ≳4 × 1015 W.

Upper limits on transmitter rate of extragalactic civilizations placed by Breakthrough Listen observations

ABSTRACT The Search for Extra-Terrestrial Intelligence (SETI) has been conducted for over 60 yr, yet no technosignatures have been identified. Previous studies have focused on stars in our Galaxy, with few searches in the extragalactic Universe despite a larger volume being available. Civilizations capable of harvesting energy from a star or a galaxy are classified as KII or KIII on the Kardashev scale, respectively. Technosignatures from such advanced civilizations would be extremely luminous and detectable by current radio telescopes, even from distant galaxies. To explore the frontier of extragalactic SETI, we investigate the likely prevalence of extragalactic civilizations possessing a radio transmitter, known as the transmitter rate, based on observational results from the Breakthrough Listen (BL) observations. We calculated the transmitter rate by considering the background galaxies in the field of view of target stars in BL observations. We used a statistical method to derive the total mass of stars in those background galaxies from a galaxy stellar mass function. Our statistical method suggests that less than one in hundreds of trillions of extragalactic civilizations within 969 Mpc possess a radio transmitter above 7.7 × 1026 W of power, assuming one civilization per one-solar-mass stellar system. Additionally, we cross-matched the BL survey fields with the WISE × SuperCOSMOS Photometric Redshift Catalogue and compared with the statistical method. Our result sets the strictest limits to date on the transmitter rate at such high-power levels, emphasizing the high efficiency of searching for radio transmitters in galaxies and the rarity of technologically advanced civilizations in our Universe.

Multibeam Blind Search of Targeted SETI Observations toward 33 Exoplanet Systems with FAST

The search for extraterrestrial intelligence (SETI) is to search for technosignatures associated with extraterrestrial life, such as engineered radio signals. In this paper, we apply the multibeam coincidence matching (MBCM) strategy, and propose a new search mode based on the MBCM which we call the MBCM blind search mode. In our recent targeted SETI research, 33 exoplanet systems are observed by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). With this blind search mode, we search for narrowband drifting signals across 1.05–1.45 GHz in two orthogonal linear polarization directions separately. There are two special signals, one of which can only be detected by the blind search mode while the other can be found by both blind and targeted search modes. This result reveals huge advantages of the new blind search mode. However, we eliminate the possibility of the special signals being ETI signals based on much evidence, such as the polarization, drift, frequency, and beam coverage characteristics. Our observations achieve an unprecedented sensitivity and our work provides a deeper understanding to the polarization analysis of extraterrestrial signals.

The Breakthrough Listen Search for Intelligent Life: A Laser Search Pipeline for the Automated Planet Finder

The Search for Extraterrestrial Intelligence has traditionally been conducted at radio wavelengths, but optical searches are well-motivated and increasingly feasible due to the growing availability of high-resolution spectroscopy. We present a data analysis pipeline to search Automated Planet Finder (APF) spectroscopic observations from the Levy Spectrometer for intense, persistent, narrow-bandwidth optical lasers. We describe the processing of the spectra, the laser search algorithm, and the results of our laser search on 1983 spectra of 388 stars as part of the Breakthrough Listen search for technosignatures. We utilize an empirical spectra-matching algorithm called SpecMatch-Emp to produce residuals between each target spectrum and a set of best-matching catalog spectra, which provides the basis for a more sensitive search than previously possible. We verify that SpecMatch-Emp performs well on APF-Levy spectra by calibrating the stellar properties derived by the algorithm against the SpecMatch-Emp library and against Gaia catalog values. We leverage our unique observing strategy, which produces multiple spectra of each target per night of observing, to increase our detection sensitivity by programmatically rejecting events that do not persist between observations. With our laser search algorithm, we achieve a sensitivity equivalent to the ability to detect an 84 kW laser at the median distance of a star in our data set (78.5 ly). We present the methodology and vetting of our laser search, finding no convincing candidates consistent with potential laser emission in our target sample.

Frank Drake, “The Father of SETI”, May 28, 1930, to September 2, 2022

Frank Drake was a hero, a legend, an icon. His eponymous Drake Equation was the catalyst forSETI—the search for extraterrestrial intelligence. It is often called the second most famousequation in physics, right up there with E = mc2. His name is recognized by highschoolstudents—a pantheon that includes names such as Newton, Einstein, Gauss, Maxwell, Planck,Boltzmann.

Specular Reflections from Artificial Surfaces as Technosignature.

Direct imaging of exoplanets will allow for observation of a planet in reflected light. Such a scenario may eventually allow for the possibility to scan a planetary surface for the presence of artificial structures made by alien civilizations. Detectability of planetary-scale structures, called megastructures, has been previously explored. In this work, we show that it is possible to detect structures of much smaller scale on exoplanetary surfaces by searching for the specular reflection of host starlight from the corresponding structures. As the planet rotates, these reflections can manifest as an optical transient riding atop the rotational light curve of the planet. Due to the directional nature of specular reflection, the reflected signal is very strong, and it is comparable to the planetary flux for surfaces that cover only a few parts per million of the total planetary surface area. By tracking the planet around its orbit, it should be possible to scan the planetary surface for any such structures that cover a size larger than a few parts per million of planetary surface. The proposed method will aid in the search for extraterrestrial intelligence in the era of direct imaging of exoplanets.