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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 ...

The Astronomical Journal, 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 100 times larger than any of our samples, we propose an easily accessible citizen science project in search of USNO-B1.0 objects which have disappeared from the SDSS.

2014

existed. Starting in the late 1950s, researchers have been performing progressively more sensitive searches, but each search has been limited by the technologies available at the time. As radio frequency technologies have become more efficient and computers have become faster, the searches have grown larger and more sensitive. The

2019

The discovery of the ubiquity of habitable extrasolar planets, combined with revolutionary advances in instrumentation and observational capabilities, have ushered in a renaissance in the millenia-old quest to answer our most profound question about the Universe and our place within it - Are we alone? The Breakthrough Listen Initiative, announced in July 2015 as a 10-year 100M USD program, is the most comprehensive effort in history to quantify the distribution of advanced, technologically capable life in the universe. In this white paper, we outline the status of the on-going observing campaign with our primary observing facilities, as well as planned activities with these instruments over the next few years. We also list collaborative facilities which will conduct searches for technosignatures in either primary observing mode, or commensally. We highlight some of the novel analysis techniques we are bringing to bear on multi-petabyte data sets, including machine learning tools we ...

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?"

Malaga International Astronautical Federation Congress, 1989

This paper estimates the maximum range at which radar signals from the Earth could be detected by a search system similar to the NASA Search for Extraterrestrial Intelligence Microwave Observing Project (SETI MOP) assumed to be operating out in the galaxy. Figures are calculated for the Targeted Search, and for the Sky Survey parts of the MOP, both operating, as currently planned, in the second half of the decade of the 1990s. Only the most powerful terrestrial transmitters are considered, namely, the planetary radar at Arecibo in Puerto Rico, and the ballistic missile early warning systems (BMEWS). In each case the probabilities of detection over the life of the MOP are also calculated. The calculation assumes that we are only in the eavesdropping mode. Transmissions intended to be detected by SETI systems are likely to be much stronger and would of course be found with higher probability to a greater range. Also, it is assumed that the transmitting civilization is at the same level of technological evolution as ours on Earth. This is very improbable. If we were to detect another technological civilization, it would, on statistical grounds, be much older than we are and might well have much more powerful transmitters. Both factors would make detection by the NASA MOP a much more likely outcome.

In the book On the Origin of Extraterrestrial Industrial Civilizations, four cases of analysis of possible existence of earth like civilization in the cosmos are setup. That is, projected future Type III civilizations derived from earth analog-based civilizations are both rare in space and time. Projected future Type III civilizations derived from earth analog-based civilizations are becoming more frequent in space but not in time, Projected future Type III civilizations derived from earth analog-based civilizations are becoming more frequent in time but not in space, and finally, the projected future Type III civilizations derived from earth analog-based civilizations are becoming both more frequent in time and in space. The majority of the book was focused on the modeling of the last case, which is the most likely scenario in which a contact can become possible and the most complex case compares to the former three since it is based on global regulatory mechanism and the relative ease at abiogenesis. In the book, we proposed the nearest civilizations possible to earth given our current understanding of biology and evolution and assuming earth biological history served as the typical trajectory. In this paper, using the concept of self indication assumption, the lower bound can also be settled, surprisingly the lower bound is likely be only two orders of magnitudes below the upper bound, despite a much larger possible spread of prior probability on the chance of low likelihood of abiogenesis. We also used self indication assumption for our earliest window, and we find that despite a possible window size of 4 Gyr according to the Lineweaver scale, much more recent, shorter earliest window is favored. Abstract Finally, over the course of time, other authors have proposed various explanatory mechanisms for possible detection/non-detection of extraterrestrial civilizations, we try to clarify the entire landscape by presenting all possible cases all at once and fitting them into our conceptual framework.

Publications of the Astronomical Society of the Pacific, 2017

We present the target selection for the Breakthrough Listen search for extraterrestrial intelligence during the first year of observations at the Green Bank Telescope, Parkes Telescope and Automated Planet Finder. On the way to observing 1,000,000 nearby stars in search of technological signals, we present three main sets of objects we plan to observe in addition to a smaller sample of exotica. We choose the 60 nearest stars, all within 5.1 pc from the sun. Such nearby stars offer the potential to observe faint radio signals from transmitters having a power similar to those on Earth. We add a list of 1649 stars drawn from the Hipparcos catalog that span the Hertzprung-Russell diagram, including all spectral types along the main sequence, subgiants, and giant stars. This sample offers diversity and inclusion of all stellar types, but with thoughtful limits and due attention to main sequence stars. Our targets also include 123 nearby galaxies composed of a "morphological-type-complete" sample of the nearest spirals, ellipticals, dwarf spherioidals, and irregulars. While their great distances hamper the detection of technological electromagnetic radiation, galaxies offer the opportunity to observe billions of stars simultaneously and to sample the bright end of the technological luminosity function. We will also use the Green Bank and Parkes telescopes to survey the plane and central bulge of the Milky Way. Finally, the complete target list includes several classes of exotica, including white dwarfs, brown dwarfs, black holes, neutron stars, and asteroids in our Solar System.