In the ever growing realm of acronyms, you can't do much better than COSMIC - the Commensal Open-Source Multimode Interferometer Cluster Search for Extraterrestrial Intelligence. This is a collaboration between the SETI Institute and the National Radio Astronomy Observatory (NRAO), which operates the Very Large Array in New Mexico. The news out of COSMIC could not be better for technosignature hunters: Fiber optic amplifiers and splitters are now installed at each of the 27 VLA antennas. What that means is that COSMIC will have access to the complete datastream from the entire VLA, in effect an independent copy of everything the VLA observes. Now able to acquire VLA data, the researchers are proceeding with the development of high-performance Graphical Processing Unit (GPU) code for data analysis. Thus the search for signs of technology among the stars gains momentum at the VLA. Image: SETI Institute post-doctoral researchers, Dr Savin Varghese and Dr Chenoa Tremblay, in front of one...

What expectations do we bring to the hunt for life elsewhere in the universe? Opinions vary depending on who has the podium, but we can neatly divide the effort into two camps. The first looks for biosignatures, spurred by our remarkably growing and provocative catalog of exoplanets. The other explicitly looks for signs of technology, as exemplified by SETI, which from the start hunted for signals produced by intelligence. My guess is that a broad survey of those looking for biosignatures would find that they are excited by the emerging tools available to them, such as new generations of ground- and space-based telescopes, and the kind of modeling we saw in the last post applied to a hypothetical Alpha Centauri planet. We use our growing datasets to examine the nature of exoplanets and move beyond observation to model benchmarks for habitable worlds, including their atmospheric chemistry and even geology. Technosignatures are a different matter, and it's fascinating to read through a...

Before getting into the paper I want to discuss today, I want to mention the new biography of John von Neumann by Ananyo Bhattacharya. I make no comment on The Man from the Future (W. W. Norton & Company, 2022) yet because while I have a copy, I haven't had time to read it. But be aware that it’s out there – it’s getting good reviews, and given the impact of this remarkable figure on everything from programmable computers to game theory and the interstellar dispersion of civilizations, it’s a book you’ll at least want to stick on your reference list. I figure anyone who masters calculus by the age of eight, as von Neumann is reputed to have done, is going to turn out to make a substantial contribution somewhere. I’m also interested in how polymaths function, moving with what seems effortless ease through diverse fields of study and somehow leaving their mark on each. What a contrast to our age of micro-specialization, where relentless drilling down into a single topic – and this...

The Dyson sphere has become such a staple of SETI as well as science fiction that it’s hard to conceive how lightly Freeman Dyson himself took the idea. In a 2008 interview with Slate, he described the Dyson sphere as no more than ‘a little joke,’ and noted “it's amusing that of course you get to be famous only for the things you don't think are serious.” Indeed, Dyson’s 1960 paper “Search for Artificial Stellar Sources of Infrared Radiation,” was but a one-page document in Science that grew out of his notion that an intelligent civilization might not have any interest in communicating. How, then, would astronomers on Earth go about finding it? Waste heat was his answer, a nod to the laws of thermodynamics and the detectability of such heat in the infrared. Coming hard on the heels of Frank Drake’s Project Ozma (a likewise playful name, coined out of affection for L. Frank Baum's imaginary land of Oz), Dyson saw a search for what would come to be called Dyson spheres as a complement...

Although so-called Dysonian SETI has been much in the air in recent times, its origins date back to the birth of SETI itself. It was in 1960 – the same year that Frank Drake used the National Radio Astronomy Observatory in Green Bank, West Virginia to study Epsilon Eridani and Tau Ceti – that Freeman Dyson proposed the Dyson sphere. In fiction, Olaf Stapledon had considered such structures in his novel Star Maker in 1937. As Macy Huston and Jason Wright (both at Penn State) remind us in a recent paper, Dyson’s idea of energy-gathering structures around an entire star evolved toward numerous satellites around the star rather than a (likely unstable) single spherical shell. We can’t put the brakes on what a highly advanced technological civilization might do, so both solid sphere and ‘swarm’ models can be searched for, and indeed have been, for in SETI terms we’re looking for infrared waste heat. And if we stick with Dyson (often a good idea!), we would be looking for structures...

If SETI is all about intelligence, and specifically technology, at the other end of astrobiology is the question of abiogenesis. Does life of any kind in fact occur elsewhere, or does Earth occupy a unique space in the scheme of things? Alex Tolley looks today at one venue where life may evolve, deep inside planetary crusts, with implications that include what we may find "locally" at places like Europa or Titan. In doing so, he takes a deep dive into a new paper from Jeffrey Dick and Everett Shock, while going on to speculate on broader questions forced by life's emergence. Organisms appearing in the kind of regions we are discussing today would doubtless be undetectable by our telescopes, but with favorable energetics, deep ocean floors may spawn abundant life outside the conventional habitable zone, just as they have done within our own 'goldilocks' world. by Alex Tolley Are the deep hot ocean vents more suitable for life than previously thought? In a previous article [1] I...

As we puzzle out the best observing strategies to pick up a bio- or technosignature, we're also asking in what ways our own world could be observed by another civilization. If such exist, they would have a number of tools at their disposal by which to infer our existence and probe what we do. Extrapolation is dicey, but we naturally begin with what we understand today, as Brian McConnell does in this, the third of a three-part series on SETI issues. A communications systems engineer, Brian has worked with Alex Tolley to describe a low-cost, high-efficiency spacecraft in their book A Design for a Reusable Water-based Spacecraft Known as the Spacecoach (Springer, 2015). His latest book is The Alien Communication Handbook -- So We Received A Signal, Now What? recently published by Springer Nature. Is our existence so obvious to the properly advanced observer? That doubtless depends on the state of their technology, about which we know nothing, but if the galaxy includes billion-year old...

If you were crafting a transmission to another civilization -- and we recently discussed Alexander Zaitsev's multiple messages of this kind -- how would you put it together? I'm not speaking of what you might want to tell ETI about humanity, but rather how you could make the message decipherable. In the second of three essays on SETI subjects, Brian McConnell now looks at enclosing computer algorithms within the message, and the implications for comprehension. What kind of information could algorithms contain vs. static messages? Could a transmission contain programs sufficiently complex as to create a form of consciousness if activated by the receiver's technnologies? Brian is a communication systems engineer and expert in translation technology. His book The Alien Communication Handbook (Springer, 2021) is now available via Amazon, Springer and other booksellers. by Brian S McConnell In most depictions of SETI detection scenarios, the alien transmission is a static message, like...

If we ever do receive a targeted message from another star – as opposed to picking up, say, leakage radiation – will we be able to decipher it? We can’t know in advance, but it's a reasonable assumption that any civilization wanting to communicate will have strategies in place to ease the process. In today's essay, Brian McConnell begins a discussion on SETI and interstellar messaging that will continue in coming weeks. The limits of our understanding are emphasized by the problem of qualia; in other words, how do different species express inner experience? But we begin with studies of other Earth species before moving on to data types and possible observables. A communication systems engineer and expert in translation technology, Brian is the author of The Alien Communication Handbook -- So We Received A Signal, Now What?, recently published by Springer Nature under their Astronomer’s Bookshelf imprint, and available through Amazon, Springer and other booksellers. by Brian McConnell...

I always knew where I stood with Alexander Zaitsev. In the period 2008-2011, he was a frequent visitor on Centauri Dreams, drawn initially by an article I wrote about SETI, and in particular whether it would be wise to go beyond listening for ETI and send out directed broadcasts to interesting nearby stars. At that time, I was straddling the middle on METI -- Messaging to Extraterrestrial Intelligence -- but Dr. Zaitsev found plenty of discussion here on both sides, and he joined in forcefully. Image: Alexander Leonidovich Zaitsev, METI advocate and radio astronomer, whose messages to the cosmos include the 1999 and 2003 'Cosmic Calls' from Evpatoria. Credit: Seth Shostak. The Russian astronomer, who died last week, knew where he stood, and he knew where you should stand as well. As my own views on intentional broadcasts moved toward caution in future posts, he and I would have the occasional email exchange. He was always courteous but sometimes exasperated. When I was in his good...

If self-reproducing probes have ever been turned loose in the Milky Way, they may well have spread throughout the galaxy. Our planet is 4.6 billion years old, but the galaxy's age is 13 billion, offering plenty of time for this spread. A number of papers have explored the concept, including work by Frank Tipler, who in 1980 argued that even at the speed of current spacecraft, the galaxy could be completely explored within 300 million years. Because we had found no evidence of such probes, Tipler concluded that extraterrestrial technological civilizations did not exist. Robert Freitas also explored the consequences of self-reproducing probes in that same year, reaching similar conclusions about how quickly they would spread, although not buying Tipler's ultimate conclusion. It's interesting that Freitas went to work on looking for evidence, reasoning that halo orbits around the Lagrangian points might be one place to search. He was, to my knowledge, the first to use the term SETA --...

I’m looking at a paper just accepted at The Astrophysical Journal on the subject of panspermia, the notion that life may be distributed through the galaxy by everything from interstellar dust to comets and debris from planetary impacts. We have no hard data on this -- no one knows whether panspermia actually occurs from one planet to another, much less from one stellar system to another star. But we can investigate possibilities based on what we know of everything from the hardiness of organisms to the probabilities of ejecta moving on an interstellar trajectory. In “Panspermia in a Milky Way-like Galaxy,” lead author Raphael Gobat (Pontificia Universidad Católica de Valparaíso, Chile) and colleagues draw together current approaches to the question and develop a modeling technique based on our assumptions about galactic habitability and simulations of galaxy structure. Panspermia is an ancient concept. Indeed, the word first emerges in the work of Anaxagoras (born ca. 500–480 BC) and...

Extraterrestrial civilizations, if they exist, would pose a unique challenge in comprehension. With nothing in common other than what we know of physics and mathematics, we might conceivably exchange information. But could we communicate our cultural values and principles to them, or hope to understand theirs? It was Ludwig Wittgenstein who said "If a lion could speak, we couldn't understand him." True? One perspective on this is to look not into space but into time. Traditional SETI is a search through space and only indirectly, through speed of light factors, a search through time. But new forms of SETI that look for technosignatures -- and this includes searching our own Solar System for signs of technology like an ancient probe, as Jim Benford has championed -- open up the chronological perspective in a grand way. Now we are looking for conceivably ancient signs of a civilization that may have perished long before our Sun first shone. A Dyson shell, gathering most of the light...

If we were to find a civilization at Proxima Centauri, the nearest star, it would either be a coincidence of staggering proportions -- two technological cultures just happening to thrive around neighboring stars -- or an indication that intelligent life is all but ubiquitous in the galaxy. ‘Ubiquitous’ could itself mean different things: Many civilizations, scattered in their myriads amongst the stars, or a single, ancient civilization that had spread widely through the galaxy. If a coincidence, add in the time factor and things get stranger still. For only the tiniest fraction of our planet’s existence has been impinged upon by a tool-making species, and who knows what the lifetime of a civilization is? Unless civilizations can live for eons, how could two of them be found around stars so close? Thus the possibility that BLC1 -- Breakthrough Listen Candidate 1 -- was a valid technosignature at Proxima Centauri was greeted with a huge degree of skepticism within the SETI community...

If you could send out a fleet of small lightsails, accelerated to perhaps 20 percent of the speed of light, you could put something of human manufacture into the Alpha Centauri triple star system within about 20 years. So goes, of course, the thinking of Breakthrough Starshot, which continues to investigate whether such a proposal is practicable. As the feasibility study continues, we'll learn whether the scientists involved have been able to resolve some of the key issues, including especially data return and the need for power onboard to make it happen. The concept of beam-driven sails for acceleration to interstellar speeds goes back to Robert Forward (see Jim Benford's excellent A Photon Beam Propulsion Timeline in these pages) and has been examined for several decades by, among others, Geoffrey Landis, Gregory Matloff, Benford himself (working with brother Greg) in laboratory experiments at JPL, Leik Myrabo, and Chaouki Abdallah and team at the University of New Mexico. At the...

I try to keep my ear to the ground (rather than my eye to the sky) when it comes to SETI. What I mean is that there are enough scientists working SETI issues that it's a challenge to know who is doing what. I try to track ongoing discussions even when, as at a conference, people keep ducking into and out of audibility. Hence the possibility of overlap in SETI efforts and, as Jason Wright points out in a discussion on his AstroWright site, the circulation of the same ideas without moving the ball forward. This is hardly a new phenomenon, as a look back at my own grad school experience in a much different area reveals. I was a medievalist with an ear for language, and I was always struck by how compartmentalized we tended to be when discussing medieval linguistics. At that time, northern European tongues like Gothic, Old Icelandic, Anglo-Saxon and Old Saxon formed a scholarly thicket I happily wandered through, but in the absence of computerized resources back in the day, the Gothic...

Vladimir Airapetian, senior astrophysicist in the Heliophysics Division at NASA’s Goddard Space Flight Center, has a somewhat unusual ambition. Most attention related to finding a ‘second Earth’ revolves around locating a world not only similar to ours in its characteristics but also similarly situated in terms of its host star’s evolution. In other words, a rocky world scorched by its star’s transition to red giant status isn’t a true analogue of our own, but a glimpse of what it will be at another stage. What Airapetian has in mind, though, is going in the other direction. His projected Earth analogue is one that mimics what our planet was in its early days, not all that long after the birth of its stellar system. It’s an ambition that points to learning where we came from, and thus what we might expect when we see a system like ours evolving around other stars. It has led to a search for a star like the Sun in its infancy. Says Airapetian: “It’s my dream to find a rocky exoplanet...

If we ever find life on a planet orbiting a white dwarf star, it will be life that has emerged only after the red giant phase has passed and the white dwarf has emerged as a stellar relic. That's the conclusion of a study being discussed today at the National Astronomy Meeting of Britain's Royal Astronomical Society, which convened online due to COVID concerns. The work is also recently published in Monthly Notices of the Royal Astronomical Society. At issue is the damage caused by powerful stellar winds that occur as a star makes the transition from red giant to white dwarf stage. This is the scenario that awaits our own Sun, which should swell to red giant status in roughly five billion years, eventually becoming a dense white dwarf about the size of the Earth. We've speculated in these pages about life surviving this phase of stellar evolution, but the study, in the hands of Dimitri Veras (Warwick University) concludes that this is all but impossible. We know that the Earth is...

I sometimes rely on nudges from my software to remind me of directions I've been meaning to take in a Centauri Dreams article. Seeing that Caleb Scharf has a new book out (The Ascent of Information), I was setting about ordering it when I noticed how many notes I had on my hard disk related to Scharf's work, a reminder of how provocative I find his writings. That took me back to a 2018 article called The Selfish Dataome, and also to the recent article The Origin of Technosignatures, which appeared a few days ago in Scientific American. Scharf (Columbia University) has the habit of asking questions no one else seems to have thought of. So let's kick this around a bit. The notion of a 'dataome' is about external things that a species generates. Scharf defines it as: a deeper way to quantify intelligent life, based on the external information that a species generates, utilizes, propagates and encodes in what we call technology—everything from cave paintings and books to flash...

Although we've been focusing lately on photosynthesis, radiolysis -- the dissociation of molecules by ionizing radiation -- can produce food and energy for life below the surface and in deep oceans. Our interest in surface conditions thus needs to be complemented by the investigation of what may lie within, as Alex Tolley explains in today's essay. Indeed, biospheres in a planet's crust could withstand even the destruction of all surface life. The possible range of microorganisms well beyond the conventional habitable zone defined by liquid water is wide, and while detecting it will be challenging, we may be able to investigate the possibilities in our own system with landers, looking to a day when interstellar probes are possible to explore exoplanet interiors. by Alex Tolley "There may be only one garden of Eden here for large life forms such as ourselves. But living beings small enough to populate tiny pore spaces may well exist within several - and perhaps many-other planetary...