Related papers: Too Damned Quiet?
Biological activities are often seen entrained onto the day-night and other celestial mechanical cycles (e.g., seasonal and lunar), but studies on the origin of life have largely not accounted for such periodic external environmental…
It is argued that the "generic" evolutionary pathway of advanced technological civilizations are more likely to be optimization-driven than expansion-driven, in contrast to the prevailing opinions and attitudes in both future studies on one…
We combine a semi-analytic model of galaxy evolution with constraints on circumstellar habitable zones and the distribution of terrestrial planets to probe the suitability of galaxies of different mass and type to host habitable planets,…
What is habitability? Can we quantify it? What do we mean under the term habitable or potentially habitable planet? With estimates of the number of planets in our Galaxy alone running into billions, possibly a number greater than the number…
Interstellar travel in the Milky Way is commonly thought to be a long and dangerous enterprise, but are all galaxies so hazardous? I introduce the concept of galactic traversability to address this question. Stellar populations are one…
Theory and observation for the search for life on exoplanets via atmospheric "biosignature gases" is accelerating, motivated by the capabilities of the next generation of space- and ground-based telescopes. The most observationally…
You and I are highly unlikely to exist in a civilization that has produced only 70 billion people, yet we find ourselves in just such a civilization. Our circumstance, which seems difficult to explain, is easily accounted for if (1) many…
The problem of the search for the satellites of the exoplanets (exomoons) is discussed recently. There are very many satellites in our Solar System. But in contrary of our Solar system, exoplanets have significant eccentricity. In process…
Comparison of the total number of the radar astronomy transmissions with respect to that used for sending messages to extra-terrestrial civilizations reveals that the probability of detection of the radio signals to extraterrestrials (ETs)…
Interstellar signals might be intermittent for many reasons, such as targeted sequential transmissions, or isotropic broadcasts that are not on continuously, or many other reasons. The time interval between such signals would be important,…
The discovery of an increasing number of Jupiter-like planets in orbit around other stars (or extra-solar planets) is a promising first step toward the search for Life in the Universe. We review all aspects of the question: - definition of…
Throughout the entire history of terrestrial civilization, only four projects involving transmitting of interstellar radio messages (IRMs) have yet been fully developed and realized. Nevertheless, we should understand a simple thing -- if…
In this article an analysis of the fundamentals used to search for extraterrestrial artificial signals in the galaxy, which have been developing for more than five decades, is presented. It is shown that the key factor for the success of…
Modern machine learning methods have been proposed to detect life in extraterrestrial samples, drawing on their ability to distinguish biotic from abiotic samples based on training models using natural and synthetic organic molecular…
The fermi paradox uses an appeal to the mediocrity principle to make it seem counter-intuitive that humanity has not been contacted by extraterrestrial intelligence. A numerical, statistical analysis was conducted to determine whether this…
A complex message from space may require the use of computers to display, analyze and understand. Such a message cannot be decontaminated with certainty, and technical risks remain which can pose an existential threat. Complex messages…
At this point in time, there is very little empirical evidence on the likelihood of a space-faring species originating in the biosphere of a habitable world. However, there is a tension between the expectation that such a probability is…
The astrobiology is an interdisciplinary science, combining the methods and the means of physics, biology, chemistry and astronomy. Its main purpose is to find out if the exoplanets are habitable and if so, to confirm life on them. The…
How good is our universe at making habitable planets? The answer to this depends on which factors are important for life: Does a planet need to be Earth mass? Does it need to be inside the temperate zone? are systems with hot Jupiters…
The observed orbits of extrasolar planets suggest that many giant planets migrate a considerable distance towards their parent star as a result of interactions with the protoplanetary disk, and that some of these planets become trapped in…