We've long discussed intercepting not only beacons but stray radio traffic from other civilizations. The latter may be an all but impossible catch for our technology, but there is a third possibility: Perhaps we can intercept the 'leakage' from a beamed power infrastructure used to accelerate another civilization's spacecraft. The idea has been recently quantified in the literature, and Jim Benford examines it here in light of a power-beaming infrastructure he has studied in detail on the interplanetary level. The CEO of Microwave Sciences, Benford is a frequent contributor to these pages and an always welcome voice on issues of SETI and its controversial cousin METI (Messaging to Extraterrestrial Intelligence). by James Benford Beaming of power to accelerate sails for a variety of missions has been a frequent topic on this site. It has long been pointed out that beaming of power for interplanetary commerce has many advantages. Beaming power for space transportation purposes can...

I have no idea whether we would be able to recognize a Kardashev Type III civilization if we saw one, but the search is necessary as we rule out some possibilities and examine others. As we saw yesterday, the Glimpsing Heat from Alien Technologies project at Penn State has examined data on 100,000 galaxies, finding 93 with mid-infrared readings that merit further study. One thing that we, operating with what we know about physics, would expect from a super-civilization is the production of waste heat, in the temperature range between 100 and 600 K, and that’s why previous searches for Dyson spheres have gone looking for such signatures. But Kardashev Type III is an extreme reach. We’re talking about a civilization capable of using the energies not just of its own star but of its entire galaxy, and just how this would be done is a question about which we can only speculate. As Erik Zackrisson (Uppsala University) and colleagues do in a new paper that balances nicely against Michael...

‘Dysonian SETI’ is all about studying astronomical data in search of evidence of advanced civilizations. As such, it significantly extends the SETI paradigm both backwards and forwards in time. It moves forward because it offers entirely new search space in not just our own galaxy but galaxies throughout the visible universe. But it also moves backward in the sense that we can use vast amounts of stored observational data from telescopes both ground- and space-based to do the work. We don’t always need new instruments to do SETI, or even new observations. With Dysonian SETI, we can do a deep dive into our increasingly abundant digital holdings. At Penn State, Jason Wright and colleagues Matthew Povich and Steinn Sigurðsson have been conducting the Glimpsing Heat from Alien Technologies (G-HAT) project, which scans data in the infrared from the Wide-field Infrared Survey Explorer (WISE) mission and the Spitzer Space Telescope. This is ground-breaking work that I’ve written about here...

Would panspermia, the idea that primitive life can spread from star to star, be theoretically observable? Henry Lin and Abraham Loeb (both associated with the Harvard-Smithsonian Center for Astrophysics) believe the answer is yes. In a paper accepted for publication in Astrophysical Journal Letters, the duo make the case that panspermia would create statistical correlations regarding the distribution of life. Detecting biosignatures in the atmospheres of exoplanets may eventually allow us to apply statistical tests in search of these clustering patterns. If panspermia occurs, the paper argues, we can in principle detect it. "In our theory,” says Lin, “clusters of life form, grow, and overlap like bubbles in a pot of boiling water." The paper argues that future surveys like TESS (Transiting Exoplanet Survey Satellite) could be an early step in building the statistical database needed. TESS could detect hundreds of terrestrial-class explanets, some of whose atmospheres will be subject...

We recently looked at the $100 million infusion into the SETI effort by Yuri Milner, with backing by major figures in the field. When I'm considering SETI developments, I always look to Michael Michaud, whose judicious perspective in his book Contact with Alien Civilizations (Copernicus, 2007) remains a touchstone. He served in senior international science and technology positions with the U.S. State Department and two American embassies and acted as chairman of working groups at the International Academy of Astronautics that discuss SETI issues, in addition to publishing numerous articles and papers on the implications of contact. Michaud recently addressed the Astrobiology Science Conference 2015 (AbSciCon2015) in Chicago in mid-June, more than a month before the Breakthrough Initiatives announcement, and touched on many of the relevant themes. What follows is an essay drawn from that talk but expanded with new material and references. What if a very advanced technology is...

SETI received a much needed boost this morning as Russian entrepreneur Yuri Milner, along with physicist Stephen Hawking and a panel including Frank Drake, Ann Druyan, Martin Rees and Geoff Marcy announced a $100 million pair of initiatives to reinvigorate the search. The first of these, Breakthrough Listen, dramatically upgrades existing search methods, while Breakthrough Message will fund an international competition to create the kind of messages we might one day send to other stars, although the intention is also to provoke the necessary discussion and debate to decide the question of whether such messages should be sent in the first place. With $100 million to work with, SETI suddenly finds itself newly affluent, with significant access to two of the world's largest telescopes -- the 100-meter Green Bank instrument in West Virginia and the 64-meter Parkes Telescope in New South Wales. The funding will also allow the Automated Planet Finder at Lick Observatory to search at...

Imagine a civilization one million years old. As Nick Nielsen points out in today's essay, the 10,000 year span of our terrestrial civilization would only amount to one percent of the older culture's lifetime. The 'zoo hypothesis' considers extraterrestrials studying us as we study animals in controlled settings. Can a super-civilization study a planetary culture for the whole course of its technological development? Nielsen, an author and strategic analyst, runs a thought experiment on two possible courses of observation, asking how we would be perceived by outsiders, and how they might relate us to the history of their own development. by J. N. Nielsen In 1973 John A. Ball wrote a paper published in Icarus called "The Zoo Hypothesis" in which he posited an answer to the Fermi paradox involving the deliberate non-communication of advanced ETI (extraterrestrial intelligence) elsewhere in our universe: "…the only way that we can understand the apparent non-interaction between...

Our definition of the habitable zone is water-based, focusing on planetary surfaces warm enough that liquid water can exist there. New work by Steven Benner (Foundation for Applied Molecular Evolution) and colleagues considers other kinds of habitable zones, specifically those supporting hydrocarbons, which can be liquids, solids or gases depending on the ambient temperature and pressure. Benner's work focuses on compounds called ethers that can link together to form polyethers, offering life a chance to emerge and adapt in hydrocarbon environments. Out of this comes the notion of 'warm Titans,' moons with hydrocarbon seas that are not made up of methane. We have no such worlds in our Solar System, and they needn't be moons of gas giants to fit the bill. Think of them, as this Astrobio.net news release does, as being oily Earths drenched in hydrocarbons like propane or octane. Although they do not appear in any genetic molecules on Earth, ethers may be the key to fill the function of...

It was natural enough that Richard Carrigan would come up with the model for what he called ‘Fermi bubbles,’ which I invoked in Monday’s post. A long-time researcher of the infrared sky, Carrigan (Fermi National Accelerator Laboratory, now retired) had mined data from the Infrared Astronomical Satellite (IRAS) in 2009 to mount a search for interesting sources that could be Dyson spheres, entire stars enclosed by a swarm of power stations, or conceivably wrapped entirely by a sphere of material presumably mined from the planetary population of the system. Carrigan’s work on infrared sources goes back well over a decade, involving not only data mining but theorizing about the nature of truly advanced civilizations. If we were to find a civilization transforming a galaxy by gradually building Dyson spheres to exploit all the energies of its stars, we would be witnessing the transformation from Kardashev Type II (a culture that uses all the power of its star) to Type III (a culture that...

I’m enough of a perfectionist that when I get something wrong, I can’t rest easy until I figure out how and why I missed the story. Such a case occurred in an article I wrote for Aeon Magazine called Distant Ruins. The article covered the rise of so-called ‘Dysonian SETI,’ which is adding an entirely new dimension to current radio and optical methods by looking into observational evidence for advanced civilizations in our abundant astronomical data. In the story, I homed in at one point on the work that Jason Wright and his colleagues Matthew Povich and Steinn Sigurðsson are doing with the Glimpsing Heat from Alien Technologies (G-HAT) project at Penn State. Keith Cooper went over the basics of this effort on Friday, putting his own spin on the group’s recent search of 100,000 galaxies. For more background, see Jason Wright’s Glimpsing Heat from Alien Technologies essay. I noted in the Aeon article that the G-HAT team was examining infrared data from the Wide-field Infrared Survey...

Our speculations about advanced civilizations invariably invoke Nikolai Kardashev’s scale, on which a Type III civilization is the most advanced, using the energy output of its entire galaxy. Given the age of our universe, a Type III has seemingly had time to emerge somewhere, yet a recent extensive survey shows no signs of them. All of this leads Keith Cooper to consider possible reasons for the lack, including societies that use their energies in ways other than we are imagining and cultures whose greatest interest is less in stars than in their galaxy’s black holes. Keith is an old friend of Centauri Dreams, with whom I’ve conducted published dialogues on interstellar issues in the past (look for these to begin again). A freelance science journalist and contributing editor to Astronomy Now, Keith's ideas in the essay below help to illuminate the new forms of SETI now emerging as we try to puzzle out the enigma of Kardashev Type III. By Keith Cooper It’s not often that SETI turns...

by James Benford Searching for the faintest of signals in hopes of detecting an extraterrestrial civilization demands that we understand the local environment and potential sources of spurious signals. But we've also got to consider how signals might be transmitted, the burden falling on SETI researchers to make sense out of the physics (and economics) that constrain distant beacon builders. James Benford, CEO of Microwave Sciences and a frequent Centauri Dreams contributor, now looks at the problem in light of recent transients and discusses how we should move forward. The recent activity on Perytons leads us to a major lesson. We have a vast microwave network all around us that can interfere with transient radio astronomy. Our cell phones, though not powerful, influence the stronger transmitters and antennas of the cell phone towers. Add to that the many Internet hubs, microwave ovens, wireless equipment and extensive communication webs. All these may have fast transients with...

A new paper out of the Glimpsing Heat from Alien Technologies search (G-HAT) at Penn State is packed with fascinating reading, and I’m delighted to send you in its direction (citation below) for a further dose of the energizing concepts of ‘Dysonian SETI.’ Supported by a New Frontiers in Astronomy and Cosmology grant funded by the John Templeton Foundation, G-HAT has been studying whether highly advanced civilizations are detectable through their waste heat at mid-infrared wavelengths, a tell-tale signature posited by Freeman Dyson in the 1960s. We now have the highly useful dataset of some 100 million entries gathered by WISE, the Wide-field Infrared Survey Explorer mission, to work with. G-HAT researcher Roger Griffith, lead author of the paper on this work, went through these data, culling out 100,000 galaxies that could be seen with sufficient detail, and searching for any that produced an unusually strong mid-infrared signature. Fifty galaxies do show higher levels of...

If you want to send a message to the stars, Jon Lomberg is the man to consult. A gifted artist and creator of the gorgeous Galaxy Garden in Kona, Hawaii, Lomberg may be most famous for his frequent work with Carl Sagan, including the celebrated Cosmos series. But it’s his involvement with the Voyager Interstellar Record, a project for which he served as design director, that makes him so uniquely qualified to embark on a new messaging effort, the One Earth: New Horizons Message project. Let’s talk about Voyager and how the new message differs. 115 images and 27 musical selections went into the Voyager record, along with abundant audio of the life and natural sounds of our planet. The 12-inch gold-plated copper disk included spoken greetings in fifty-five languages beginning with Akkadian (a language of ancient Sumer) and ending with Wu, a modern Chinese dialect. The ninety minutes of music can be played at 16 ? revolutions per minute using a cartridge and needle enclosed within the...

Recently we looked at Fast Radio Bursts (FRBs) and the ongoing effort to identify their source (see Fast Radio Bursts: SETI Implications?) Publication of that piece brought a call from my friend James Benford, a plasma physicist who is CEO of Microwave Sciences. Jim noticed that the article also talked about a different kind of signal dubbed 'perytons,' analyzed in a 2011 paper by Burke-Spolaor and colleagues. Detected at the Parkes radio telescope, as were all but one of the FRBs, perytons remain a mystery. As described in the essay below, Jim's recent trip to Australia gave him the opportunity to discuss the peryton question with key players in the radio astronomy community there. He has a theory about what causes these odd signals that is a bit closer to home than some of our speculations on the separate Fast Radio Burst question, and as he explains, we'll soon know one way or another if he's right. by James Benford A few weeks ago I visited Swinburne University in Melbourne...

With SETI on my mind after last week's series on Dysonian methods, it seems a good time to discuss Fast Radio Bursts, which have become prominent this week following the appearance of a new paper. A New Scientist piece titled Is this ET? Mystery of strange radio bursts from space is also circulating, pointing out that these powerful bursts of radio waves lasting for milliseconds, each covering a broad range of radio frequencies, are still unexplained, and that they seem to follow a mathematical pattern. Image: The 64-metre Parkes radio telescope in New South Wales (Australia), where Fast Radio Bursts of unknown origin have been detected. Credit: CSIRO Parkes Observatory. Eleven bursts have been detected so far, dating back to 2001. The paper, by Michael Hippke (Institute for Data Analysis, Neukirchen-Vluyn, Germany), Wilfried Domainko (Max-Planck-Institut fur Kernphysik, Heidelberg) and John Learned (University of Hawaii, Manoa), points out that the pulses have dispersion measures...

This has been a week devoted to extraterrestrial technologies and the hope that, if they exist, we can find them. Large constructions like Dyson spheres, and associated activities like asteroid mining on the scale an advanced civilization might use to make them, all factor into the mix, and as we've seen, so do starships imagined in a wide variety of propulsion systems and designs. Dysonian SETI, as it is called, takes us into the realm of the hugely speculative, but hopes through sifting our abundant astronomical data to find evidence of distant engineering. This effort is visible in projects like the Glimpsing Heat from Alien Technologies (G-HAT) SETI program, which proceeds in the capable hands of Jason Wright and colleagues Steinn Sigurðsson and Matthew Povich at Penn State (see Wright's Glimpsing Heat from Alien Technologies essay in these pages as well as his AstroWright blog). For those wanting to follow up these ideas, an excellent introduction is the paper "Dysonian Approach...

There is a wonderful moment in Larry Niven’s 1970 novel Ringworld when protagonist Louis Wu is first shown an image of an artificial ring completely encircling a star. These days the concept of a Dyson sphere is well established as a way for a civilization to capture as much energy as possible from the host star, but back then I had never heard of the concept. Dyson thought both a solid shell and a ring would be unstable and believed the best form for his concept was what he described as “...a loose collection or swarm of objects traveling on independent orbits around the star.” In that sense, Niven’s Ringworld wasn’t really Dysonian, but I found it staggering. What a place! An engineered ring the diameter of Earth’s orbit fully 1.6 million kilometers wide, giving a habitable inner surface equal to about three million Earth-sized planets. A broader backdrop for science fiction adventure could scarcely be imagined unless it were a full-blown Dyson sphere. And indeed, Ringworld became...

We've talked often enough about the so-called 'Fermi paradox' in these pages, but Gregory Benford recently passed along a new paper from Robert H. Gray making the case that there is in fact no paradox, and that Fermi's intentions have been misunderstood. It's an interesting point, because as it turns out, Fermi himself never published anything on the subject of interstellar travel or the consequences if it proved possible. The famous lunch conversation at Los Alamos in 1950 when he asked 'Where is everybody' (or perhaps 'Where are they') has often been seen as a venue for Fermi to express his doubts about the existence of any extraterrestrial civilization, and the 'Fermi Paradox' has become a common trope of interstellar studies. Robert Gray (Gray Consulting, Chicago) believes this is a misunderstanding, and sorts through the aftermath of that particular event. It would be another 27 years before the term 'Fermi paradox' even appeared in print, inserted into a JBIS paper by D. G....

We're discovering planets around other stars at such a clip that moving to the next step -- studying their atmospheres for markers of life -- has become a priority. But what techniques will we use and, more to the point, how certain can we be of their results? Centauri Dreams columnist Andrew LePage has been mulling these matters over in the context of how we've approached life on a much closer world. Before the Viking landers ever touched down on Mars, a case was being made for life there that seemed compelling. LePage's account of that period offers a cautionary tale about astrobiology, and a ringing endorsement of the scientific method. A senior project scientist at Visidyne, Inc., Drew is also the voice behind Drew ex Machina. by Andrew LePage Every time I read an article in the popular astronomy press about how some new proposed instrument will allow signs of life to be detected on a distant extrasolar planet, I cannot help but be just a little skeptical. For those of us with...