I think you'll find Jon Lomberg's new essay in Slate as interesting as I do. We Need a World Cup for SETI uses a familiar figure at many sports events -- the guy in the stands holding up a Biblical reference on a poster -- to dig into a far more interesting issue. How does one go about maximizing visibility? The guy with the sign knows how to do it and if we think about his methods, we can better understand SETI. For as we think about radio and optical SETI, we're usually looking for signals that have been intentionally sent. Here we run into the particularly tricky business of trying to understand the thinking of an alien being, but there are certain principles that may apply to any civilization trying to send out a beacon-like message. The message needs to be short, cheap, easy to find, and in a place where it's likely to be seen. So what kind of beacon is this going to be? We've discussed 'Benford beacons' in these pages before (see, among others in the archive, Detecting a...

Last week I mentioned that I wanted to get into Massimo Marengo’s new paper on KIC 8462852, the interesting star that, when studied by the Kepler instrument, revealed an intriguing light curve. I’ve written this object up numerous times now, so if you’re coming into the discussion for the first time, plug KIC 8462852 into the archive search engine to get up to speed. Marengo (Iowa State) is himself well represented in the archives. In fact, I began writing about him back in 2005, when he was working on planetary companions to Epsilon Eridani. In the new paper, Marengo moves the ball forward in our quest to understand why the star I’ll abbreviate as KIC 8462 poses such problems. The F3-class star doesn’t give us the infrared signature we’d expect from a debris disk, yet the light curves we see suggest objects of various sizes (and shapes) transiting across its surface. What we lacked from Tabetha Boyajian’s earlier paper (and it was Boyajian, working with the Planet Hunters group,...

KIC 8462852 is back in the news. And despite a new paper dealing with the unusual star, I suspect it will be in the news for some time to come, for we’re a long way from finding out what is causing the unusual light curves the Planet Hunters group found in Kepler data. KIC 8462, you’ll recall, clearly showed something moving between us and the star, with options explored by Tabetha Boyajian, a Yale University postdoc, in a paper we examined here in October (see KIC 8462852: Cometary Origin of an Unusual Light Curve? and a series of follow-up articles). To recap, we’re seeing a light curve around this F3-class star that doesn’t look anything like a planetary transit, but is much more suggestive of debris. Finding a debris disk around a star is not in itself unusual, since we’ve found many such around young stars, but KIC 8462 doesn’t appear to be a young star when looked at kinematically. In other words, it’s not moving the way we would expect from a star that has recently formed....

Plasma physicist James Benford, CEO of Microwave Sciences, is well known here on Centauri Dreams. Today he is joined by his son Dominic, whose work focuses on the development of ultrasensitive technologies for far-infrared through millimeter-wave astronomy. The younger Dr. Benford is Program Scientist for NASA's WFIRST mission, which is designed to conduct major surveys in the near-infrared to answer fundamental questions on the nature of dark energy, the distribution of dark matter, the occurrence of planets around other stars, and even to enable the direct imaging of planetary systems. Previously, Dominic was Chief Scientist for the Cosmic Origins Program Office, as well as Deputy Mission Scientist for WISE, the Wide-field Infrared Survey Explorer. In today's entry, the Benfords look at the SETI Institute's recent observations of KIC 8462852 and analyze the detectability of power beaming at these distances. by James and Dominic Benford The recent report from the SETI Institute of...

I've mentioned before that I think the name 'Tabby's Star' is a wonderful addition to the catalog. It trips off the tongue so much more easily than the tongue-twisting KIC 8462852, and of course it honors the person who brought this unusual object to our attention, Yale University postdoc Tabetha Boyajian. 1480 light years away, Tabby's Star is an F3 with a difference. It produces light curves showing objects transiting across its face, some of them quite large, and the search is on to find an explanation that fits within the realm of natural causes. Five articles about Tabby's Star have already appeared in these pages, with the most likely explanation being some kind of cometary activity, an answer that seems to satisfy no one. We've also consulted both Boyajian's paper on the subject and a paper by Jason Wright and colleagues out of the Glimpsing Heat from Alien Technologies project at Penn State. The light curves we're looking at do fit the scenario of a 'Dyson swarm,' a cluster...

How do you feel about a universe that shows no signs of intelligent life? Let’s suppose that we pursue various forms of SETI for the next century or two and at the end of that time, find no evidence whatsoever for extraterrestrial civilizations. Would scientists of that era be disappointed or simply perplexed? Would they, for that matter, keep on looking? I suspect the latter is the case, not because extraterrestrial civilizations would demonstrate that we’re not alone, but because in matters of great scientific interest, it’s the truth we’re after, not just the results we want to see. In my view, learning that there was no other civilization within our galaxy -- at least, not one we can detect -- would be a profoundly interesting result. It might imply that life itself is rare, or even more to the point, that any civilizations that do arise are short-lived. This is that tricky term in the Drake equation that refers to the lifespan of a technological civilization, and if that...

Back from my break, I have to explain to those who asked about what exotic destination I was headed for that I didn’t actually go anywhere (the South Pacific will have to wait). The break was from writing Centauri Dreams posts in order to concentrate on some other pressing matters that I had neglected for too long. Happily, I managed to get most of these taken care of, all the while keeping an eye on interstellar news and especially the interesting case of KIC 8462852 (for those just joining us, start with KIC 8462852: Cometary Origin of an Unusual Light Curve? and track the story through the next two entries). Whatever the explanation for what can only be described as a bizarre light curve from this star, KIC 8462852 is a significant object. While Dysonian SETI has been percolating along, ably studied by projects like Glimpsing Heat from Alien Technologies, the public has continued to see SETI largely in terms of radio and deliberate attempts to communicate. Tabetha Boyajian and...

I had no idea when the week began that I would be ending it with a third consecutive post on Dysonian SETI, but the recent paper on KIC 8462852 by Tabetha Boyajian and colleagues has forced the issue. My original plan for today was to focus in on Cassini’s work at Enceladus, not only because of the high quality of the imagery but the fact that we’re nearing the end of Cassini’s great run investigating Saturn’s icy moons. Then last night I received Jason Wright’s new paper (thanks Brian McConnell!) and there was more to say about KIC 8462852. Actually, I’m going to look at Wright’s paper in stages. It was late enough last night that I began reading it that I don’t want to rush a paper that covers a broad discussion of megastructures around other stars and how their particular orbits and properties would make them stand out from exoplanets. But the material in the paper on KIC 8462852 certainly follows up our discussion of the last two days, so I’ll focus on that alone this morning....

I want to revisit the paper on KIC 8462852 briefly this morning, as I’m increasingly fascinated with the astrophysics we’re digging into here. The fact that the star, some 1480 light years away, is also a candidate for further SETI investigation makes it all the more intriguing, but all my defaults lean toward natural processes, if highly interesting ones. Let’s think some more about what we could be looking at and why the ‘cometary’ hypothesis seems strongest. Remember that we’re looking at KIC 8462852 not only because the Kepler instrument took the relevant data, but because the Kepler team took advantage of crowdsourcing to create Planet Hunters, where interested parties could sign up to study the light curves of distant stars on their home computers. KIC 8462852 has been causing ripples since 2011 because while we do seem to be seeing something passing between its light and us, that something is not a planet but a large number of objects in motion around the star. Some of the...

Dysonian SETI operates under the assumption that our search for extraterrestrial civilizations should not stop with radio waves and laser communications. A sufficiently advanced civilization might be visible to us without ever intending to establish a dialogue, observed through its activities around its parent star or within its galaxy. Find an anomalous object difficult to explain through conventional causes and you have a candidate for much closer examination. Is KIC 8462852 such a star? Writing for The Atlantic, Ross Andersen took a look at the possibilities yesterday (see The Most Mysterious Star in Our Galaxy), noting that this F3-class star puts out a light curve indicating not a planetary transit or two, but a disk of debris. That wouldn't be cause for particular interest, as we've found numerous debris disks around young stars, but by at least one standard KIC 8462852 doesn't appear to be young. In a paper on this work, Tabetha Boyajian, a Yale University postdoc, and...

We often conceive of SETI scenarios in which Earth scientists pick up a beacon-like signal from another star, obviously intended to arouse our attention and provide information. But numerous other possibilities exist. Might we, for example, pick up signs of another civilization's activities, perhaps through intercepting electromagnetic traffic, or their equivalent of planetary radars? Even more interesting, as Brian McConnell speculates below, is the idea of listening in on a galactic network that contains information not just from one civilization but many. As Centauri Dreams readers know, McConnell and Alex Tolley have been developing the 'spacecoach' concept of interplanetary travel, discussed in the just published A Design for a Reusable Water-Based Spacecraft Known as the Spacecoach (Springer, 2015). It's a shrewd and workable way to get us deep into the Solar System. Today McConnell turns his attention to a SETI network whose detection could offer a big payoff for a young...

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...