Computer failures can happen any time, but it's been so long since I've had a hard disk failure that I rarely worry about such problems. Part of my relaxed stance has to do with backups, which I always keep in triplicate, so when I discovered Friday afternoon that one of my hard disks had failed -- quickly and catastrophically -- it was more of a nuisance than anything else. It meant taking out the old disk, going out to buy a new one and installing same, and then loading an operating system on it. Because I do 90 percent of my work in Linux, I opted for Linux Mint as a change of pace from Ubuntu, making it the tenth version of Linux I've used over the years. My weekend was mildly affected, but the new disk went in swiftly and the operating system load went without incident, so I was still able to get to two concerts, one of them an absolutely brilliant handling of Elgar's 'Enigma Variations,' and to see the new Tommy Lee Jones movie 'Emperor.' Hardware failures in the midst of an...
Biological Evolution in Interstellar Human Migration
Centauri Dreams is happy to welcome Dr. Cameron M. Smith, a prehistorian at Portland State University's Department of Anthropology in Portland, OR, with an essay that is the capstone of this week's worldship theme. Dr. Smith began his career excavating million-year-old stone tools in Africa and today combines his archaeological interests with a consideration of human evolution and space colonization. He is applying this interest in his collaboration with the scientists at Icarus Interstellar's Project Hyperion, a reference study for an interstellar craft capable of voyaging to a distant star. Recently Dr. Smith presented a paper at the NASA/DARPA '100 Year Starship Study' conference in Houston, Texas. His recent popular science publications in this field include "Starship Humanity" (Scientific American 2013) and the book Emigrating Beyond Earth: Human Adaptation and Space Colonization (Springer-Praxis, 2013). We can look forward to a follow-up article to this one in coming weeks. by...
Habitable Zone Planets: Upping the Numbers
Whether we're planning to go to the stars on a worldship or with faster transportation, the choice of targets is still evolving, and will be for some time. Indeed, events are moving almost faster than I can keep up with them. It was in early February that Courtney Dressing and David Charbonneau (Harvard-Smithsonian Center for Astrophysics) presented results of their study of 3897 dwarf stars with temperatures cooler than 4000 K, revising their temperatures downward and reducing their size by 31 percent. The scientists culled the stars from the Kepler catalog, and their revisions had the effect of lowering the size of the 95 detected planets in their data. They went on to deduce that about 15 percent of all red dwarf stars have an Earth-sized planet in the habitable zone. [PG note: The 15% figure is a revised estimate that I've just learned about from Ravi kumar Kopparapu. Dressing and Charbonneau call attention to this change at the end of their paper. See citation below]. That would...
Life Aboard the Worldship
Konstantin Tsiolkovsky is the first person I know of to talk about worldships and their ramifications, which he did in an essay originally published in 1928. "The Future of Earth and Mankind" was the rocket pioneer's take on the need for enormous ships that could reach the stars in journeys taking thousands of years. The notion percolated quickly through science fiction, and by 1940 we have Don Wilcox's "The Voyage that Lasted 600 Years," which ran in Amazing Stories. Wilcox, who taught creative writing at Northwestern University, imagined a ship's captain who, though kept in hibernation, wakes up every 100 years to check on his ship, watching the gradual degeneration of the successive generations of the crew. It's a bleak take on worldship travel that has often been echoed in later science fiction. But would a worldship actually be this horrific, a cruise from hell that lasted entire lifetimes? See Ken MacLeod's Learning the World: A Novel of First Contact (2005) for the worldship...
Space Habitats and Nearby Resources
If humans go out into the Solar System and beyond drawing on the resources they find along the way, they don't necessarily have to do it on worldships of the kind we talked about yesterday. But it's a reasonable assumption that creating large space habitats would make engineering projects in deep space easier to implement, housing workers and providing a base for operations. Ken Roy presented ideas about habitats in the Kuiper Belt at Huntsville, including the possibility of a large colony being created inside objects like Pluto. If we choose to go that route, we'll have the kind of space expertise to create artificial objects similar to worldships to help ourselves along. Of course, we hardly need to limit ourselves to the Kuiper Belt for this kind of thinking. Whatever the design of the ships we use, we can also consider expansion into the vast cometary resources of the Oort Cloud and any other objects that may lurk there, including so-called rogue planets. For years we've kicked...
Toward a Space-Based Civilization
The assumptions we bring to interstellar flight shape the futures we can imagine. It's useful, then, to question those assumptions at every turn, particularly the one that says the reason we will go to the stars is to find other planets like the Earth. The thought is natural enough, and it's built into the exoplanet enterprise, for the one thing we get excited about more than any other is the prospect of finding small, rocky worlds at about Earth's distance from a Sun-like star. This is what Kepler is all about. From an astrobiological perspective, this focus makes sense, as we want to know whether there is other life -- particularly intelligent life -- in the universe. But interstellar expansion may not involve terrestrial-class worlds at all, though they would still remain the subject of intense study. Let's assume for a moment that a future human civilization expands to the stars in worldships that take hundreds or even thousands of years to reach their destination. The occupants...
Stranger Than Fiction
Just what does it take to make a habitable world? Keith Cooper is editor of Astronomy Now, the British monthly whose first editor was the fabled Patrick Moore. An accomplished writer on astronautics and astronomy as well as a Centauri Dreams regular, Keith has recently become editor of Principium, the newsletter of the Institute for Interstellar Studies, whose third issue has just appeared. In this essay, Keith looks at our changing views of habitable zones in light of recent work, and takes us to two famous science fictional worlds where extreme climates challenge life but do not preclude it. How such worlds emerge and how life might cope on them are questions as timely as the latest exoplanet findings. by Keith Cooper Literally overnight, two habitable planets - tau Ceti f and HD 85512b - were rendered barren and lifeless. What was the cause of this cataclysm? A nearby supernova? Asteroid impacts? On the contrary, it was something far more mundane. A dozen light years away,...
SETI: The Artificial Transit Scenario
Among the many memorable things Freeman Dyson has said in a lifetime of research, one that stands out for me is relatively recent. “Look for what is detectable, not for what is probable.” This was Dyson speaking at a TED conference in Monterey, CA back in 2003, making the point that the universe continually surprises us, and by making too many assumptions about what we are looking for, we may miss unexpected things that can advance our understanding. Dyson has been thinking about this for a long time considering that it was way back in 1960 that he first suggested looking for the excess infrared radiation that might flag a distant Dyson sphere. I would call this an unorthodox approach to SETI in its day except that when he first came up with it, Dyson didn’t have a SETI effort to consider. It was only in the same year that Cornell’s Frank Drake began SETI observations at Green Bank, and a scant year before that that Philip Morrison and Giuseppe Cocconi published the seminal paper...
Into Europa’s Ocean
Europa continues to fascinate us with the possibility of a global ocean some 100 kilometers deep, a vast body containing two to three times the volume of all the liquid water on Earth. The big question has always been how thick the icy crust over this ocean might be, and we've looked closely at Richard Greenberg's analysis, which shows surface features he believes can only be explained by interactions between the surface and the water, making for a thin crust of ice. See Unmasking Europa: Of Ice and Controversy for more, and ponder the prospects of getting some kind of future probe through a thin ice layer to explore the potentially habitable domain below. Possible interactions between the surface and the ice are considered in a new paper by Mike Brown (Caltech) and Kevin Hand (JPL), one that makes the case that there are two ways of thinking about Europa. One is to see the Jovian moon purely as an ice shell upon which the bombardment of electrons and ions have created a chemical...
A Framework for Interstellar Flight
Those of us who are fascinated with interstellar travel would love to see a probe to another star launched within our lifetime. But maybe we're in the position of would be flyers in the 17th Century. They could see birds wheeling above them and speculate on how humans might create artificial wings, but powered flight was still centuries ahead. Let's hope that's not the case with interstellar flight, but in the absence of any way of knowing, let's continue to attack the foundational problems one by one in hopes of building up the needed technologies. Marc Millis, who ran NASA's Breakthrough Propulsion Physics project at the end of the 20th Century, always points out in his talks that picking this or that propulsion technology as the 'only' way to get to the stars is grossly premature. In a recent interview with the Australian Broadcasting Corporation's Antony Funnell, Millis joined physicist and science fiction writer Gregory Benford, Icarus Interstellar president Richard Obousy and...
Interstellar Ice Grains and Life’s Precursors
One of the first science fiction novels I ever read was The Black Cloud, by astrophysicist Fred Hoyle. I remember that one of my classmates had smuggled it into our grade school and soon we were passing it around covertly instead of reading whatever it was we had been assigned. In Hoyle's novel, scientists discover that the cloud, which approaches the Solar System and decelerates, may be a life-form with which they can communicate. My young self was utterly absorbed by this book and I suspect it will hold up well to re-reading. What brings The Black Cloud to mind is recent work using data from the Green Bank Telescope in West Virginia, where scientists have been studying an enormous gas cloud some 25,000 light years from Earth near the center of the Milky Way in the star forming region Sagittarius B2(N). This cloud is not, of course, behaving as entertainingly as Hoyle's, but it's offering up information about how interstellar molecules that are intermediate steps toward the final...
Icarus Interstellar – A Grass Roots Community
One of the pleasures of conferences like the recent Huntsville gathering is the chance to meet up with old friends. Richard Obousy and I had been talking about his offering a review of Icarus Interstellar's recent work for some time, and Huntsville gave us the chance to firm up the idea. The article below is the result, an examination of the Icarus team's current structure and planning as they continue with the Project Icarus starship design and look toward other interstellar possibilities. The president and senior scientist for Icarus, Richard is a familiar face on Centauri Dreams. He did his doctoral work at Baylor University, studying the possibility that dark energy could be an artifact of Casimir energy in extra dimensions. He's now engaged in planning the Icarus conference this summer, about which more shortly. By Richard Obousy Having served as President of Icarus Interstellar for 18 months now, I've been privileged to be knee deep in the evolving face of this exciting...
Mars Flyby: Daring to Venture
Existential risks, as discussed here yesterday, seem to be all around us, from the dangers of large impactors to technologies running out of control and super-volcanoes that can cripple our civilization. We humans tend to defer thinking on large-scale risks while tightly focusing on personal risk. Even the recent events near Chelyabinsk, while highlighting the potential danger of falling objects, also produced a lot of fatalistic commentary, on the lines of 'if it's going to happen, there's nothing we can do about it.' Some media outlets did better than others with this. Risk to individuals is understandably more vivid. When Apollo 8 left Earth orbit for the Moon in 1968, the sense of danger was palpable. After all, these astronauts were leaving an orbital regime that we were beginning to understand and were, by the hour, widening the distance between themselves and our planet. But even Apollo 8 operated within a sequenced framework of events. Through Mercury to Gemini and Apollo, we...
Bostrom: From Extinction to Transcendence
At the top of my list of people I'd someday like to have a long conversation with is Nick Bostrom, a philosopher and director of Oxford's Future of Humanity Institute. As Centauri Dreams readers will likely know, Bostrom has been thinking about the issue of human extinction for a long time, his ideas playing interestingly against questions not only about our own past but about our future possibilities if we can leave the Solar System. And as Ross Andersen demonstrates in Omens, a superb feature on Bostrom's ideas in Aeon Magazine, this is one philosopher whose notions may make even the most optimistic futurist think twice. I suppose there is such a thing as a 'philosophical mind.' How else to explain someone who, at the age of 16, runs across an anthology of 19th Century German philosophy and finds himself utterly at home in the world of Schopenhauer and Nietzsche? Not one but three undergraduate degrees at the University of Gothenburg in Sweden followed. Now Bostrom applies his...
Life Around Dying Stars
Where is the best place to look for life? At first glance, a red dwarf would seem to be the ideal choice because a transiting terrestrial-class world in the habitable zone of a red dwarf is going to block a larger part of the star’s light than a similarly sized world orbiting a larger star. Red dwarfs pose their own problems for life, including the possibility of tidal lock and severe flares, but in terms of detectability, they seem made to order for planet hunters with transit methods in mind. But white dwarfs turn out to be interesting targets in their own right, and in at least one significant way may offer even more advantages. So says a new paper by Avi Loeb (Harvard-Smithsonian Center for Astrophysics) and Don Maoz (Tel Aviv University), who point out that a habitable planet orbiting a white dwarf would have to be close to its star indeed, perhaps as close as 1.5 million kilometers. As with a red dwarf, a transit here will block a large fraction of the star’s light --...
Looking Back from Deep Space
It's reasonable to call the two Voyager spacecraft our first interstellar probes, in the sense that they are approaching the heliopause and are still transmitting data. Long before controllers shut them down -- which should occur somewhere in the 2020s -- Voyager 1 will have left the Solar System and we'll have data on what happens when the solar wind gives way to the stellar winds from beyond. A case could be made for the Pioneer craft as interstellar probes as well, but while Pioneer 10 has reached a distance of 107 AU, the Pioneers are no longer transmitting data. Voyager 1 is now 123.45 AU out, for a round-trip light time of 34 hours, 15 minutes. But does leaving the Solar System mean we've truly entered interstellar space? An entertaining piece called Postcards from the edge, published in early February by The Economist, notes that much depends on how we define 'interstellar.' Gravity, says its author, defines the universe at the largest scales, and if we're talking about...
Starships of the Mind
Michael Michaud wrote the essay that follows back in 1978 for a now-defunct magazine that never published it. In recent correspondence about Daedalus designer Alan Bond, Michael referred to the essay and I asked him to forward a copy, which had also passed through the hands of Freeman Dyson and Bob Forward not long after he wrote it. Although it is dated, Starships of the Mind does a wonderful job presenting the major interstellar propulsion ideas, leavened with Michael's innate optimism, which has inspired me for many years. It's a bit of starship history that deserves to be in circulation, and Michael was kind enough to agree. Many thanks are owed as well to my friend David Warlick, who scanned the original and, through the wonders of optical character recognition, rendered it into digital form. Centauri Dreams readers will know Michael Michaud as the author of Contact with Alien Civilizations: Our Hopes and Fears about Encountering Extraterrestrials (Springer, 2007), an essential...
Small Planets Confirm Kepler’s Capabilities
The planetary system around Kepler-37, some 210 light years from Earth in the constellation Lyra, had its place in the media spotlight yesterday, although it will surely be a brief one. But it's heartening to see the quickening interest in exoplanets that each new discovery brings. Will the interest continue? In the Apollo days, public enthusiasm reached a frenzy as we moved toward the first lunar landings, then plummeted. What the media see as the big event in exoplanetary science is the discovery of a terrestrial world around a star like the Sun. Let's hope there is no similar letdown afterwards. After all, we're getting close, and discoveries like those announced yesterday remind us that Kepler can find very small worlds indeed. Kepler-37b lays claim to being the smallest planet yet found around a star similar to the Sun, similar in this case meaning a G-class star with a radius about three-quarter's of the Sun's. The new planet is just a bit larger than our Moon, as the image...
Resources Between the Stars
Yesterday we looked at the possibility of colonizing worlds much different from the Earth. Seen in one light, pushing out into the Kuiper Belt and building settlements there is part of a slow migration to the stars that may occur without necessarily being driven by that purpose. Seen in another, experimenting with human settlements in extreme environments is a way of exploiting the resources of nearby space, pushing the human presence out into the Oort Cloud. Either way, we can find places that, while not 'habitable' in the classic sense of liquid water at the surface, are nonetheless colonizable. In his Tale of Two Worlds, novelist Karl Schroeder works on a definition of a colonizable world. It has to have an accessible surface, for one thing, meaning one we can work with -- obviously a surface gravity of 4 g's is going to be a problem. Much smaller worlds like Pluto, as we saw yesterday in Ken Roy's work on possible colonies there, pose less of a challenge, as we can imagine...
Interstellar Expansion: Colonizing Ice Dwarfs
Are habitable planets the best places to look for life? The question seems odd, because we're assuming life has to have clement conditions to emerge and survive. But step beyond the question of life's formation and the issue can be framed differently. Where beyond its birthplace might life migrate? In SETI terms, where might we look for the signature of a civilization advanced enough to move beyond its home world and expand between the stars? A lot of ideas seem to be converging here. In Huntsville, Ken Roy (whose description at the recent interstellar conference was 'an engineer living and working amidst the relics of the Manhattan Project in Oak Ridge, Tennessee') described potential habitats stretching far out into the Solar System and beyond. Roy has been working for some time with Robert Kennedy and David Fields on colonization scenarios. My own talk covered the kind of places where we might extract resources, ranging from icy dwarfs like Pluto to cometary objects and 'rogue'...