Can rapidly advancing laser technology and optics augment the way we do SETI? At the University of California, Santa Barbara, Phil Lubin believes they can, and he's behind a project called the Trillion Planet Survey to put the idea into practice for the benefit of students. As an incentive for looking into a career in physics, an entire galaxy may be just the ticket. For the target is the nearest galaxy to our own. The Trillion Planet Survey will use a suite of meter-class telescopes to search for continuous wave (CW) laser beacons from M31, the Andromeda galaxy. But TPS is more than a student exercise. The work builds on Lubin's 2016 paper called "The Search for Directed Intelligence," which makes the case that laser technology foreseen today could be seen across the universe. And that issue deserves further comment. Centauri Dreams readers are familiar with Lubin's work with DE-STAR, (Directed Energy Solar Targeting of Asteroids and exploRation), a scalable technology that involves...

"Not all discoveries come from new observations," says Pete Worden, in a comment referring to original thinking as applied to an existing dataset. Worden is executive director of the Breakthrough Initiatives program, which includes Breakthrough Listen, an ambitious attempt to use SETI techniques to search for signs of technological activity in the universe. Note that last word: The targets Breakthrough Listen examines do extend to about one million stars in the stellar neighborhood, but they also go well outside the Milky Way, with 100 galaxies being studied in a range of radio and optical bands. A major and sometimes neglected aspect of SETI as it is reported in the media is the fact that such careful observation can turn up highly useful astronomical information unrelated to any extraterrestrial technologies. Worden's comment underlines the fact that we are generating vast data archives as our multiplying space- and ground-based instruments continue to scan the heavens at various...

While we pursue SETI by listening to and looking at nearby stars within our own galaxy, the possibility of going extragalactic remains. Consider the activity at Penn State, where Jason Wright and colleagues Matthew Povich and Steinn Sigurðsson have been conducting the Glimpsing Heat from Alien Technologies (G-HAT) project, looking at infrared data from both the Wide-field Infrared Survey Explorer mission (WISE) and the Spitzer Space Telescope. An unusual infrared signature could conceivably be a sign of waste heat from such a culture. Turning up the signature of a Kardashev Type III civilization, one capable of tapping the energy output of an entire galaxy, would be a spectacular find, a search well worth continuing. But there are other ways of looking for evidence that might fit what Wright has written about in terms of 'Schelling points.' The idea is to draw on game theory to analyze a situation in which two players who cannot communicate are engaged in a cooperative activity. They...

Now that we're getting closer to analyzing the atmospheres of terrestrial-size exoplanets, it's worth remembering how difficult the call on the existence of life is going to be. Long-time Centauri Dreams contributor Alex Tolley takes on the issue in his essay for today, pointing out along the way just how easy it is to see what we want to see in our data. While we can learn much from terrestrial biology, new approaches looking at 'pathway complexity' may offer useful indications of biology and a set of markers not constrained by our own unique sample of life on Earth. A lecturer in biology at the University of California, Alex brings us up to speed with extending our methods of life detection in ways that are 'biology agnostic.' Expect controversy ahead -- will we know life when we see it, and how can we be sure? by Alex Tolley Manuel Werner, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=633977 Life: [noun]? The condition that distinguishes animals and plants from...

Light of the Stars: Alien Worlds and the Fate of the Earth, by Adam Frank. W.W. Norton & Co. (2018), 272 pp. Although he has published several previous books and is well represented in the technical literature, Adam Frank (University of Rochester) found himself suddenly thrust onto the public stage with an op-ed he wrote in the New York Times in 2016. Chosen by the paper's editors, the title "Yes, There Have Been Aliens" injected a certainty Frank didn't intend, but it brought up an intriguing point: We may not know whether other technological civilizations exist now, but the odds are exceedingly good that at some point, somewhere, they once did. Frank and colleague Woody Sullivan had written the original idea up for Astrobiology, the result of their pondering how exoplanet data now streaming in could be used to refine the original Drake equation, which sets up the factors thought to determine the prevalence of technological societies in the universe. In his new book Light of the...

Yesterday I looked at the prospect of using technology to move entire stars, spurred on by Avi Loeb's recent paper "Securing Fuel for Our Frigid Cosmic Future." As Loeb recounts, he had written several papers on the accelerated expansion of the universe, known to be happening since 1998, and the resultant 'gloomy cosmic isolation' that it portends for the far future. It was Freeman Dyson who came up with the idea that a future civilization might move widely spaced stars, concentrating them into a small enough volume that they would remain bound by their own gravity. This escape from cosmic expansion has recently been explored by Dan Hooper, who likewise considers moving stellar populations. Image: Harvard's Avi Loeb, whose recent work probes life's survival at cosmological timescales. I gave a nod yesterday to the star-moving ideas of Leonid Shkadov, who suggested a 'Shkadov thruster' that would use the momentum of stellar photons to operate, but Loeb pointed out how inefficient the...

It's interesting to consider, as Hector Socas-Navarro does in a new paper, the various markers a technological civilization might leave. Searching for biosignatures is one thing -- we're developing the tools to examine the atmospheres of planets around nearby stars for evidence of life -- but how do we go about looking for astronomical evidence of a technological society, one found not by detection of a directed radio or laser beacon but by observation of the stars around us? Various candidates have been suggested, the most famous being the Dyson sphere, in which an advanced civilization might choose to trap the energy output of its entire star, and we're in the era of searches for such objects, as witness the Glimpsing Heat from Alien Technologies effort at Penn State. But there are many other suggestions, ranging from detecting antimatter used for power or propulsion, analyzing Fast Radio Bursts for evidence of manipulation as a propulsion system, and looking at depletion of metals...

Yesterday I looked at evidence for oxygen in a galaxy so distant that we are seeing it as it was a mere 500 million years after the Big Bang. It’s an intriguing find, because that means there was an even earlier generation of stars that lived and died, seeding the cosmos with elements heavier than hydrogen and helium. It’s hard to imagine the vast tracts of time since populated with stars and, inevitably, planets without speculating on where and when life developed. But as we continue to speculate, we should also look at the factors that could shape emerging life in galaxies like our own. Tying in neatly with yesterday’s post comes a paper from Amedeo Balbi (Università degli Studi di Roma “Tor Vergata”), working with colleague Francesco Tombesi. The authors are interested in questions of habitability not in terms of habitable zones in stellar systems but rather habitable zones in entire galaxies. For we know that at the center of our Milky Way lurks the supermassive black hole Sgr...

Ronald Bracewell's name doesn't come up as often in these pages as I might like, but today James Jason Wentworth remedies the lack. Bracewell (1921-2007), active in radio astronomy, mathematics and physics for many years at Stanford University, developed the concept of autonomous interstellar probes. Such a craft would be capable not only of taking numerous scientific readings but of communicating with any civilizations it encounters. His original paper on these matters dates back to 1960 and relies on artificial intelligence, long-life electronics and propulsion methods that don't necessarily involve high percentages of c. Jason considers these factors from the perspective of 2018 and explains what a program sending such probes to numerous stars might look like. If you're recalling Arthur C. Clarke's 'Starglider' from The Fountains of Paradise, you're not alone, but as the author notes, there are quite a few directions in which to take these ideas. by J. Jason Wentworth The writer...

How would an advanced society communicate its history and values to the stars? Bill St. Arnaud argues that just as we can uncover our own history through careful analysis of archaeological sites, so SETI might uncover traces of ETI cultures in the form of signals that take advantage of natural astrophysical processes. Read on for more on an idea Bill first broached in a Centauri Dreams post called Virtual Von Neumann Probes. A consultant and research engineer, Bill's work has involved everything from charging methods for electric vehicles to next generation Internet networks. But his interest in SETI continues to mesh with his expertise in networking in this examination of a novel way to speak from the deep past. by Bill St. Arnaud To date most SETI research has focused on the assumption that an advanced extra- terrestrial society will want to "communicate" with similar beings throughout the universe. But it is my belief that given the vast distances and time that communication via a...

The SETI effort run by Breakthrough Listen is beginning to hit on all cylinders. Yesterday came news that observations at the CSIRO Parkes Radio Telescope in New South Wales have been extended. You may recall that work at the site began in November of 2016, when Parkes joined the Green Bank Telescope (GBT) in West Virginia, USA, and the Automated Planet Finder (APF) at Lick Observatory in California in Breakthrough's search for extraterrestrial signals. Invariably, when I start talking about SETI, I recall James Gunn's masterful The Listeners, written in 1972 but made up of previously published stories on the topic that Gunn melded together with interesting transitions. Here we get a tale of the first detection of a genuine extraterrestrial civilization, the narrative mixing with not just news reports but quotes on SETI and related matters from scientists to philosophers (the technique always reminds me of Dos Passos, but as I've written before, a science fiction reference is John...

Frank Wilczek has used the neologism 'quintelligence' to refer to the kind of sentience that might grow out of artificial intelligence and neural networks using genetic algorithms. I seem to remember running across Wilczek's term in one of Paul Davies books, though I can't remember which. In any case, Davies has speculated himself about what such intelligences might look like, located in interstellar space and exploiting ultracool temperatures. A SETI target? If so, how would we spot such a civilization? Wilczek is someone I listen to carefully. Now at MIT, he's a mathematician and theoretical physicist who was awarded the Nobel Prize in Physics in 2004, along with David Gross and David Politzer, for work on the strong interaction. He's also the author of several books explicating modern physics to lay readers. I've read his The Lightness of Being: Mass, Ether, and the Unification of Forces (Basic Books, 2008) and found it densely packed but rewarding. I haven't yet tackled 2015's A...

Juggling all the factors impacting the emergence of extraterrestrial civilizations is no easy task, which is why the Drake equation has become such a handy tool. But are there assumptions locked inside it that need examination? Robert Zubrin thinks so, and in the essay that follows, he explains why, with a particular nod to the possibility that life can move among the stars. Although he is well known for his work at The Mars Society and authorship of The Case for Mars, Zubrin became a factor in my work when I discovered his book Entering Space: Creating a Spacefaring Civilization back in 2000, which led me to his scientific papers, including key work on the Bussard ramjet concept and magsail braking. Today's look at Frank Drake's equation reaches wide-ranging conclusions, particularly when we begin to tweak the parameters affecting both the lifetime of civilizations and the length of time it takes them to emerge and spread into the cosmos. by Robert Zubrin There are 400 billion other...

Anomalous objects are a problem -- we need more than one to figure them out. One 'hot Jupiter' could have been an extreme anomaly, but we went on to find enough of them to realize this was a kind of planet that had a place in our catalog. Or think of those two Kuiper Belt objects that New Horizons imaged, as discussed in yesterday's post. Soon we'll have much closer imagery of MU69, but it will take more encounters -- and more spacecraft -- to begin to fathom the full range of objects that make up the Kuiper Belt. Ultimately, we'd like to see enough KBOs up close to start drawing statistically valid conclusions about the entire population. So where does the intriguing 'Oumuamua fit into all this? It was the first interstellar asteroid we've been able to look at, even if the encounter was fleeting. A friend asked me, having learned of the Breakthrough Listen SETI monitoring of the object, whether it wasn't absurd to imagine it could be a craft from another civilization. I could only...

If for some reason I had to come up with a different name for Centauri Dreams, I think it might just be Magellanic Dreams. I say this because, like the Alpha Centauri stars themselves, the Magellanics have been something of an obsession since my childhood. Dwarf galaxies orbiting the Milky Way, the Large and Small Magellanic Clouds took my imagination outside our galaxy to a place where it could be viewed in all its splendor (or maybe not: See The Milky Way from Outside for why galaxy viewing can be problematic). The Large Magellanic Cloud is 160,000 light years away (contrast this with M-31’s 2.5 million light years), while the SMC is about 200,000 light years out. Science fiction brought us Olaf Stapledon’s telepathic aliens living in the LMC -- these guys were made to order for the emerging field of Dysonian SETI in that they did engineering on a planetary scale (see Star Maker for more). And remember where the spacecraft in Arthur C. Clarke’s Rendezvous with Rama was heading at...

Science fiction dealt with interstellar navigation issues early on. In fact, Clément Vidal's new paper, discussed in these pages yesterday, notes a George O. Smith story called "Troubled Star," which originally ran in a 1953 issue of Startling Stories and later emerged as a novel (Avalon Books, 1957). Smith is best remembered for a series of stories collected under the title Venus Equilateral, but the otherwise forgettable Troubled Star taps into the idea of using an interstellar navigation network, one that might include our own Sun. The story includes this bit of dialogue between human and the alien being Scyth Radnor, the latter explaining why his civilization would like to turn our Sun into a variable star: "We use the three-day variable to denote the galactic travel lanes. Very effective. We use the longer variable types for other things - dangerous places like cloud-drifts, or a dead sun that might be as deadly to a spacecraft as a shoal is to a seagoing vessel. It's all...

Pulsar navigation may be our solution to getting around not just the Solar System but the regions beyond it. For millisecond pulsars, a subset of the pulsar population, seem to offer positioning, navigation, and timing data, enabling autonomous navigation for any spacecraft that can properly receive and interpret their signals. The news that NASA's SEXTANT experiment has proven successful gives weight to the idea. Station Explorer for X-ray Timing and Navigation Technology is all about developing X-ray navigation for future interplanetary travel. At work here is NICER -- Neutron-star Interior Composition Explorer -- which has been deployed on the International Space Station since June as an external payload. NICER deploys 52 X-ray telescopes and silicon-drift detectors in the detection of the pulsing neutron stars called pulsars. Radiation from their magnetic fields sweeps the sky in ways that can be useful. A recent demonstration used four millisecond pulsar targets —...

Research into Boyajian's Star, otherwise known as KIC 8462852 or 'Tabby's Star,' has continued in robust fashion even as many of us were distracted by that other curiosity with a faint SETI potential, the interstellar asteroid `Oumuamua. In both cases, a highly interesting object provoked speculation as to its origins, with Boyajian's Star getting the lion's share of attention because the unusual dips in its lightcurve proved hard to explain. Now a team of more than 200 researchers led by Tabetha Boyajian herself is drawing useful conclusions about the star. Also on the team is Penn State's Jason Wright, whose interest in possible SETI signatures led him to point out that engineering on a vast scale could not immediately be ruled out. The paper now being made available in The Astrophysical Journal Letters shows that the star dims more at some wavelengths than at others. And that is, to say the least, problematic for the idea that an artificial megastructure orbits Boyajian's Star....

While the debate over sending messages to nearby stars continues, it’s interesting to probe the issue quantitatively, as Jim Benford did on Friday, asking whether recent attempts at METI could be heard at destination. The subject prompts Keith Cooper, now editor at Astrobiology Magazine, to examine ways of reaching consensus on a matter that raises strong opinions whenever it is raised. If these messages are unlikely to be heard, is there a technological window here that we can use to find consensus through continuing research? Keith is well-known to Centauri Dreams readers, having engaged with me in a series of dialogues over the years on various interstellar topics. Look for a new dialogue early in 2018. By Keith Cooper On Friday, Jim Benford’s brilliant essay showed how the latest METI signal will not even be heard at its target destination, the planet GJ 273b, which is only 12.4 light years away. Whichever side of the debate you fall on, messages that can’t be detected at their...