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...

Yesterday's post about planets in red dwarf systems examined the idea that the slow formation rate of these small stars would have a huge impact on planets that are today in their habitable zone. We can come up with mechanisms that might keep a tidally locked planet habitable, but what do we do about the severe effects of water loss and runaway greenhouse events? Keeping such factors in mind plays into how we choose targets -- very carefully -- for future space telescope missions that will look for exoplanets and study their atmospheres. But the question of atmospheres on early worlds extends far beyond what happens on M-dwarf planets. At MIT, Hilke Schlichting has been working on what happened to our own Earth's atmosphere, which was evidently obliterated at least twice since the planet's formation four billion years ago. In an attempt to find out how such events could occur, Schlichting and colleagues at Caltech and Hebrew University have been modeling the effects of impactors that...

As the Thanksgiving holiday approaches here in the US, I'm looking at a new paper in the journal Anthropocene that calls the attention of those studying sustainability to the discipline of astrobiology. At work here is a long-term perspective on planetary life that takes into account what a robust technological society can do to affect it. Authors Woodruff Sullivan (University of Washington) and Adam Frank (University of Rochester) make the case that our era may not be the first time "...where the primary agent of causation is knowingly watching it all happen and pondering options for its own future." How so? The answer calls for a look at the Drake Equation, the well-known synthesis by Frank Drake of the factors that determine the number of intelligent civilizations in the galaxy. What exactly is the average lifetime of a technological civilization? 500 years? 50,000 years? Much depends upon the answer, for it helps us calculate the likelihood that other civilizations are out there,...

Last year the New Frontiers in Astronomy & Cosmology program, set up by the John Templeton Foundation as a grant-awarding organization, dispensed three grants with a bearing on what Clément Vidal calls 'Zen SETI.' The idea of looking into our astronomical data and making new observations to track possible signs of an extraterrestrial civilization at work is not new, and yesterday we looked at Freeman Dyson's early contribution. Carl Sagan and Josif Shklovskii are also among those in a lineage we can extend back at least to the early 20th Century. The recent grants show a gathering momentum for extending SETI in new directions. The team of Jason Wright (Pennsylvania State) and colleagues Steinn Sigurðsson and Matthew Povich is embarking on a hunt for Dyson spheres, which if observed in a distant galaxy colonized by a Kardashev Type III civilization, should throw an unmistakable signature in the infrared. Could we find such an object in our data from WISE, the Wide-field...

If we're trying to extend the boundaries of the search for extraterrestrial intelligence, how do we proceed? A speculative mind is essential, and one of the delights of science fiction is the ability to move through an unrestricted imaginative space, working out the ramifications of various scenarios. But we have to prioritize what we're doing, which is why Freeman Dyson settled on the idea of looking for conspicuous examples of intelligence using technology. It's no surprise that the term 'Dysonian SETI' has arisen to describe how such a search might proceed. The Dyson sphere is a case in point. We can imagine a civilization vastly more ancient and technologically adept than our own deciding to maximize the amount of power it can draw from a star. Although Dyson spheres are sometimes pictured as shells completely surrounding a star, Dyson's ideas are more readily thought of in terms of a 'swarm' of objects soaking up as much power as possible. Other configurations are in the mix,...

The SETI challenge has often been likened to archaeology, and for good reason. In both cases, we are trying to recover information about cultures from the past. When Heinrich Schliemann dug into the numerous layers of Troy -- and in the process inadvertently damaged precious remnants of later eras -- he and his team were exploring the heroic age of Homer. Any SETI detection will likewise deal with a signal from the past. Just how old it is will depend upon how far away the source world is, for this information travels at the speed of light. The archaeology analogy is hardly perfect, because on Earth we are dealing with artifacts of our own species and are often working with linguistic remains we can decipher to aid our understanding. Figuring out Egyptian hieroglyphs wasn’t easy, but the stele known as the Rosetta Stone gave us a text in three scripts that helped us make sense of them. Even Linear B, the script of the Mycenaean Greeks before the emergence of the Greek alphabet, can...

With one interstellar conference in the books for 2014, I'll be headed next for the Tennessee Valley Interstellar Workshop, whose upcoming gathering will be held in Oak Ridge this November. Last week's coverage of the 100 Year Starship Symposium in Houston has allowed several interesting stories to back up in the queue, and I'll spend the next few days going over some of the latest findings, starting with the discovery that a large fraction of the water in Earth's oceans may be substantially older than we think. The results make a strong case for water as a common ingredient in planet formation no matter where the planet forms or around what kind of star. Ilsedore Cleeves (University of Michigan) is lead author on the new paper in Science that argues the case. What Cleeves and colleagues have found is that up to half of the water in our Solar System formed before the Sun itself emerged from the primordial gas and dust cloud that gave it birth. That encompasses more than the Earth's...

Gatherings like the 100 Year Starship Symposium have tough organizational choices to make, and the solutions aren't always obvious. A good part of any aerospace conference is involved in presenting papers, but do you set up a multi-track system or take a single-track approach? In Houston, the 100 Year Starship organization chose multiple tracks: We had, for example, a track on Life Sciences, one on Data Communications, another on Propulsion & Energy, and there were several others including a useful track on Interstellar Education. The problem is that with all these tracks running at once, it was a matter of picking and choosing, and that often meant getting up after a presentation, switching rooms, and entering another track. I missed papers in Kathleen Toerpe's Education track that I wanted to hear because I needed to hear many of the Propulsion & Energy papers, and while I caught a paper in the Becoming an Interstellar Civilization track, it was at the expense of some promising...

I like George Johnson's approach toward SETI. In The Intelligent-Life Lottery, he talks about playing the odds in various ways, and that of course gets us into the subject of gambling. What are the odds you'll hit the right number combination when you buy a lottery ticket? Whenever I think about the topic, I always remember walking into a casino one long ago summer on the Côte d'Azur. I've never had the remotest interest in gambling, and neither did the couple we were with, but my friend pulled a single coin out of his pocket and said he was going to play the slots. "This is it," he said, holding up the coin, a simple 5 franc disk (this was before the conversion to the Euro). "No matter what happens, this is all I play." He went up to the nearest slot machine and dropped the coin in. Immediately lights flashed and bells rang, and what we later calculated as the equivalent of about $225 came pouring out. Surely, I thought, he'll take at least one of these coins and play it again --...

We tend to assume that our mistakes as a species flag us as immature, a young civilization blundering about with tools it is misusing on a course that may lead to extinction. But assume for a moment that an intelligent extraterrestrial civilization goes through phases more or less like our own. If we're sifting through radio signals and looking for optical flashes to find them, shouldn't we consider other ways such a civilization announces itself? What if we're not the only polluters in the universe, for example, and other cultures are making the same mistakes? In a 2010 paper, Jean Schneider (Observatoire de Paris-Meudon) and colleagues noted the possibility of using pollutants as a way of moving beyond biosignatures to find ETI. Let me quote from the paper: ...another type of far from equilibrium signals can be seen as techno-signatures, i.e., spectral features not explained by complex organic chemistry, like laser emissions. In the present state of our knowledge one cannot...