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Planets in the Process of Formation

by Paul Gilster | Mar 24, 2016 | Exoplanetary Science | 5 Comments

Back in 2014, astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to produce high-resolution images of the planet-forming disk around the Sun-like star HL Tau, about 450 light years away in the constellation Taurus. The images were striking, showing bright and dark rings with gaps, suggesting a protoplanetary disk. Scientists believed the gaps in the disk were caused by planets sweeping out their orbits. All this was apparent confirmation of planet formation theories, but also a bit of a surprise given the age of the star, a scant million years, making this a young system indeed. Here is the ALMA image, along with the caption that ran with the original release of the story from NRAO. Image: The young star HL Tau and its protoplanetary disk. This image of planet formation reveals multiple rings and gaps that herald the presence of emerging planets as they sweep their orbits clear of dust and gas. Credit: ALMA (NRAO/ESO/NAOJ); C. Brogan, B. Saxton (NRAO/AUI/NSF)....

Gravity, Impartiality & the Media

by Paul Gilster | Mar 23, 2016 | Culture and Society | 85 Comments

Marc Millis is once again in the media, this time interviewed by a BBC crew in a show about controlling gravity. The impetus is an undertaking I described in the first chapter of Frontiers of Propulsion Science, Project Greenglow. The former head of NASA's Breakthrough Propulsion Physics project and founding architect of the Tau Zero Foundation, as well as co-editor with Eric Davis of the aforesaid book, Millis has some thoughts on how we discuss these matters in the media, and offers clarifications on how work on futuristic technologies should proceed. by Marc Millis A BBC 'Horizons' episode will air next Wednesday, March 23 (8pm UK) about the Quest for Gravity Control. The show features, among other things, an interview with myself about my related work during NASA's Breakthrough Propulsion Physics project and thereafter with the Tau Zero Foundation. Quoting from an advertisement for the show, Project Greenglow - The Quest for Gravity Control: This is the story of an extraordinary...

TVIW 2016: Homo Stellaris Working Track

by Paul Gilster | Mar 22, 2016 | Culture and Society | 8 Comments

Herewith the first of several reports on the recent Tennessee Valley Interstellar Workshop; more next week. It comes from Doug Loss, who was a participant in the Homo Stellaris working track I had hoped to attend before illness changed my plans. An experienced network and IT security administrator, Doug attended and eventually organized The Asimov Seminar from 1977 until the early 2000s, a yearly, four-day-long retreat at a conference center in upstate New York. Isaac Asimov, the noted science fiction author, was the star of the Seminar and its main draw until his death in 1992. Each year the Seminar would explore a different topic having to do with the future of human society, with Seminar attendees assuming roles that would allow them to examine the questions associated with that year's topic on a personal basis. TVIW is likewise following a highly interactive workshop strategy, as Doug's report attests. The photos below come from New York photojournalist Joey O'Loughlin, and are...

Making Centauri Dreams Reality, Virtually

by Paul Gilster | Mar 18, 2016 | Culture and Society | 31 Comments

I often think about virtual reality and the prospect of immersive experience of distant worlds using data returned by our probes. But what of the state of virtual reality today, a technology that is suddenly the talk of the computer world with the imminent release of the Oculus Rift device? Frank Taylor is just the man to ask. He has worked with computer graphics since the 1970s, starting at the University of Arizona. He worked several years at aerospace companies in support of DoD and NASA including simulation and virtual reality technology in support of astronaut training at NASA JSC. Frank has also been a successful entrepreneur doing work with Internet and other computer technologies. His most notable recent accomplishment was the completion of one orbit of the Earth at 0 MSL - he and his wife left in 2009 and sailed around the world arriving back in the US in 2015. Frank is the publisher of Google Earth Blog since 2005. Have a look now at the surprisingly wide possibilities...

Protecting Life on the Early Earth

by Paul Gilster | Mar 17, 2016 | Exoplanetary Science | 28 Comments

Kappa Ceti is a young star -- 400 to 600 million years old -- in the constellation Cetus (the Whale). It's a tremendously active place, its surface disfigured by starspots much larger and more numerous than we find on our more mature Sun. In fact, Kappa Ceti hurls enormous flares into nearby space, 'superflares' releasing 10 to 100 million times the energy of the largest flares we've ever observed on the Sun. What would be the fate of planets around a star like this? The question is directly relevant to our own system because Kappa Ceti is a G-class dwarf much like the Sun, giving us a look at what conditions would have been like when our own system was forming. The calculated age of the star, extrapolated from its spin, corresponds to the time when life first appeared on the Earth. Thus we're seeing a model of our distant past, one that makes it clear that a magnetic field is an essential for planetary habitability. The violent activity on the surface of Kappa Ceti is driving a...

What Ceres’ Bright Spots Can Tell Us

by Paul Gilster | Mar 16, 2016 | Outer Solar System | 18 Comments

Garrett P. Serviss was a writer whose name has been obscured by time, but in his day, which would be the late 19th and early 20th Century, he was esteemed as a popularizer of astronomy. He began with the New York Sun but went on to write fifteen books, eight of which focused on the field. He was also a science fiction author whose Edison's Conquest of Mars (1898) used Wellsian ideas right out of War of the Worlds. It was a sequel to an earlier story, involving master inventor Thomas Edison in combat against the Martians both on the Martian surface and off it. I think this is the first appearance of spacesuits in fiction. In any case, Serviss anticipates the 'space opera' to come, and will always have a place in the history of science fiction. I can only wonder what he would have made of the Dawn mission at Ceres. In Edison's Conquest of Mars, he refers to a race of 'Cerenites' who are, because of the low gravity of their world, about forty feet tall. They are at war with the...

StarSearch: Our Hunt for a New Home World

by Paul Gilster | Mar 14, 2016 | Culture and Society | 91 Comments

His interest fired by an interview with interstellar researcher Greg Matloff, Dale Tarnowieski became fascinated with the human future in deep space. One result is the piece that follows, an essay that feeds directly into a recent wish of mine. I had been struck by how many people coming to Centauri Dreams are doing so for the first time, and thinking that I would like to run the occasional overview article placing the things we discuss here in a broader context. Dale's essay does precisely this, looking at our future as a species on time frames that extend to the death of our planet. Dale retired in January 2015 from the position of assistant director of communications with New York City College of Technology/CUNY, a veteran journalist and editor of "Connections," the college's print and online magazine. He also did considerable writing for the New York City College of Technology Foundation and its annual Best of New York Award Dinner (and continues to do so on a freelance basis)....

Agriculture on Other Worlds

by Paul Gilster | Mar 11, 2016 | Culture and Society | 163 Comments

Because Centauri Dreams focuses on the outer system and beyond, I haven't had much to say about Mars, knowing how many good sites there are that cover developments there. But today's post is timely not only because of recent depictions of Mars in film but also because long-term sustainability is critical to a lasting human presence off-world. Dr. Ioannis Kokkinidis is a native of Piraeus, Greece. He graduated with a Master of Science in Agricultural Engineering from the Department of Natural Resources Management and Agricultural Engineering of the Agricultural University of Athens. He holds a Mastère Spécialisé Systèmes d'informations localisées pour l'aménagement des territoires (SILAT) from AgroParisTech and AgroMontpellier and a PhD in Geospatial and Environmental Analysis from Virginia Tech. Have a look now at what we could do to sustain a human settlement on another world. By Ioannis Kokkinidis I believe most readers of this blog have seen Ridley...

Aftermath: Debris Disk around a Red Giant

by Paul Gilster | Mar 10, 2016 | Deep Sky Astronomy & Telescopes | 11 Comments

Debris disks around young stars are keys to understanding how planets form. But what about debris around older stars? We now have the best view ever achieved of the dusty disk around an aging star -- a red giant -- and we’re forced to ask whether such a debris disk, so similar to what we see around young stars, could itself form a second generation of planets. The star in question is a binary designated IRAS 08544-4431, first detected by the Infrared Astronomical Satellite in the 1980s. Some 4000 light years from Earth in the direction of the southern constellation Vela (The Sails), the system contains a red giant (the source of the material in the surrounding disk) and a much smaller, less evolved companion star. Image: The dusty ring around the aging double star IRAS 08544-4431. Credit: ESO. Here we’re working with data from the Very Large Telescope Interferometer at the European Southern Observatory’s Paranal Observatory (Chile) using the PIONIER (Precision Integrated-Optics...

Into the ‘Transit Zone’

by Paul Gilster | Mar 9, 2016 | Astrobiology and SETI | 18 Comments

Given how powerful the transit method has proven for detecting exoplanets, we can assume great things are ahead. It won't be that many years before we're actually analyzing the atmospheric constituents of worlds much smaller than the gas giants for which we perform such studies now. That would make it possible for us to discover possible biosignatures. As I've speculated in these pages before, it may well be that we discover life on a planet around a distant star before we manage to discover it -- if it exists -- elsewhere in our Solar System. We're looking at worlds around other suns with something of the same spirit that Carl Sagan and the Voyager team looked back from the outer reaches and saw the Earth as a 'pale blue dot.' It's a comparison that René Heller and Ralph E. Pudritz draw in their recent paper on SETI strategy. Except here we're talking about extraterrestrial observers looking at our planet, the assumption being that if we can make these studies using our...

SETI: Knowing Where to Look

by Paul Gilster | Mar 8, 2016 | Astrobiology and SETI | 22 Comments

Running a site like Centauri Dreams means adapting and reconfiguring on a daily basis. The best laid plans and all that… When I wrote recently about the SETI efforts at KIC 8462852, my plan had been to follow up that discussion with a broader SETI issue -- where is the best place in the sky to search for a SETI signal? Then life intervened, first with my preparations to go to the Tennessee Valley Interstellar Workshop in Chattanooga, and then with the illness that cancelled those plans and left me with a thoroughly disrupted train of thought. I'm now ready to tackle that SETI question with particular reference to a new paper by René Heller and Ralph E. Pudritz, but I still want to put the discussion into context. With the KIC 8462852 SETI effort, we looked at a targeted observation campaign using the Allen Telescope Array to see if researchers could find any evidence of unusual activity associated with the star. As we saw in Jim and Dominic Benford's recent work (see...

New Eyes on the Kuiper Belt

by Paul Gilster | Mar 7, 2016 | Deep Sky Astronomy & Telescopes | 3 Comments

You probably recall how tricky it was to find 2014 MU69, the small Kuiper Belt Object that will be the next destination for our New Horizons probe. The actual extended mission to 2014 MU69 awaits a summer 2016 review within NASA, but because trajectory changes to get there could not be delayed, the New Horizons craft performed four maneuvers late last year to set the course. The search for a suitable KBO began in 2011 and it was not until 2014, working with data from the Hubble Space Telescope, that scientists were able to find their best candidate. Now consider that 2014 MU69 has a diameter of about 45 kilometers, making it ten times larger than the average comet. How difficult, then, to assess the true population of smaller Kuiper Belt Objects. We'd like to know a lot more about much smaller KBOs, because assessing the abundance and collisional processes of these objects is way of understanding the debris disks we're seeing around other stars. Current theory suggests that KBOs...

A Transiting Jupiter Analog

by Paul Gilster | Mar 4, 2016 | Exoplanetary Science | 9 Comments

David Kipping and colleagues have discovered what they describe as ‘the first validated transiting Jupiter analog,’ a planet orbiting the K-class dwarf KIC-3239945. Kepler-167e is about 90 percent the size of Jupiter and orbits its star at about twice the distance that the Earth orbits the Sun. Given the fact that the star is cooler than the Sun -- an orange rather than a yellow dwarf -- temperature estimates for the planet are in the 130 K range, only about 20 K warmer than Jupiter. The discovery is discussed on the Cool Worlds YouTube channel, an outreach project launched by the Cool Worlds Lab at Columbia University, and is the subject of a paper submitted to The Astrophysical Journal (citation below). Kepler-167e isn’t just another ‘hot Jupiter’, a class of worlds that is well populated. ‘Hot Jupiters’ occupy orbits extremely close to the parent star. Finding a true Jupiter analog -- i.e., a planet in a close to circular orbit in a position roughly analogous to Jupiter’s in our...

A New Kind of ‘Fast Radio Burst’

by Paul Gilster | Mar 3, 2016 | Deep Sky Astronomy & Telescopes | 13 Comments

A new paper in Nature offers further information about Fast Radio Bursts (FRBs), which we last looked at only a few days back. The February 24 post examined work on FRBs that were consistent with what has been seen before -- transient pulses lasting mere milliseconds, while emitting huge amounts of energy (see Fast Radio Bursts: First Distance Measurement). Now we have further work out of the Max Planck Institute for Radio Astronomy (MPIfR) in Germany that describes the detection of the first source of repeating bursts, an object outside our own galaxy that is producing multiple short bursts. Lead author Laura Spitler (MPIfR) explains that a McGill University graduate student named Paul Scholz, using data from the Arecibo radio telescope in Puerto Rico, discovered the repeat signals last November. Scholz found a total of 10 new bursts. "Not only does this source repeat, but the brightness and spectra of the bursts also differs from those of other FRBs," adds Spitler. We may be...

False Positives in the Search for Extraterrestrial Life

by Paul Gilster | Mar 2, 2016 | Astrobiology and SETI | 26 Comments

I'm still smarting about having to cancel my travel plans for the Tennessee Valley Interstellar Workshop in Chattanooga, particularly since the Tau Zero Foundation was one of the sponsors of the event. But fortunately, I do have people offering to write up the workshop for Centauri Dreams, so we'll have some coverage and photos soon. Onward… Hunting for Biosignatures We only have two years before the James Webb Space Telescope is scheduled to launch. Assuming all goes well, JWST should help ease us into the era of biosignature detection, as we look for the characteristic signs of living organisms in the atmospheres of their worlds. But just how definitive are such signatures? A new paper from the University of Washington digs into potential false positives and offers specifics on the signatures that could fool us. One way to study biosignatures is by transit spectroscopy, using data gathered from starlight as it passes through a planet's atmosphere during a transit. This...

Administrivia: Disrupted Schedule, Server Upgrade

by Paul Gilster | Mar 1, 2016 | Administrative | 21 Comments

My plan to attend the Tennessee Valley Interstellar Workshop this week fell through when I became ill two days before departure date. Talk about bad timing. TVIW is a wonderful conference, and not only was my son Miles flying in for the event, but I had planned many good conversations with friends in the interstellar community. I was also looking forward to the Homo Stellaris working track led by Robert Hampson. I've been at all previous TVIWs and deeply regret having missed this one. I'm hoping for a less foggy mind by tomorrow, at which point I'll resume the schedule here, which is four or five posts per week unless interrupted by travel. Complicating this past few days has been a server migration which apparently went well (this, thankfully, was out of my hands), and the need for a PHP upgrade, which should be occurring by the end of the week. Fingers crossed, I am hoping for no disruption. I'll hope to get some reports from TVIW and pass along links to presentations from the...

Power Beaming Parameters & SETI re KIC 8462852

by Paul Gilster | Feb 26, 2016 | Astrobiology and SETI | 111 Comments

When I first got interested in SETI, I naively assumed that we would get a detection fairly soon, and that we would detect not a directed beacon but simple background traffic in a remote civilization. I had no idea at the time how difficult it would be to pick up the kind of radio traffic we routinely generate on Earth from a distant star, and as a matter of fact, my interest in shortwave radio led me to assume that, just as I enjoyed the sport of DX -- listening for distant signals -- so SETI would simply be an offshoot of this, with a harder-to-get QSL card. Some time in the mid-1980s I wrote a piece called “Where the Real DX Is” for Glenn Hauser’s Review of International Broadcasting, running through a list of the nearest stars and talking about SETI projects that had been tried up to then. I haven’t gone back to read that article in years and would probably find it an embarrassing chore. But it’s interesting to me that the idea of leakage radiation does have its place,...

SETI: Power Beaming in Context

by Paul Gilster | Feb 25, 2016 | Astrobiology and SETI | 18 Comments

Thinking that we can understand the motivations of an extraterrestrial civilization seems like a fool's gambit, but we have to try. The reason is obvious: We have exactly one technological society to work with -- we're all we have -- and if we want to look for SETI signals, we have to interpolate as best we can. An alien culture, it is assumed, will do the same. This was the procedure outlined by Giuseppe Cocconi and Philip Morrison in their classic 1959 paper "Searching for Interstellar Communications," that began the modern era of SETI. If there are civilizations around stars like the Sun, the paper reasons, then some will be motivated to reach out elsewhere. From the paper: To the beings of such a society, our Sun must appear as a likely site for the evolution of a new society. It is highly probable that for a long time they will have been expecting the development of science near the Sun. We shall assume that long ago they established a channel of communication that would one day...

Fast Radio Bursts: First Distance Measurement

by Paul Gilster | Feb 24, 2016 | Deep Sky Astronomy & Telescopes | 11 Comments

Have we finally traced a Fast Radio Burst to its place of origin? News from the CSIRO (Commonwealth Scientific and Industrial Research Organisation) radio telescopes in eastern Australia, along with confirming data from the Japanese Subaru instrument in Hawaii, suggests the answer is yes. Fast Radio Bursts (FRBs) are transient radio pulses that last scant milliseconds. In that amount of time, they have been known to emit as much energy as the Sun emits in 10,000 years. And exactly what causes FRBs is still a mystery. Take the so-called 'Lorimer Burst' ( FRB 010724) which was discovered in archival data from 2001 at the Parkes radio telescope in New South Wales. Here we're dealing with a 30-jansky dispersed burst that was less than 5 milliseconds in duration. Although the burst appeared roughly in the direction of the Small Magellanic Cloud, the FRB is not thought to be associated with our galaxy at all. A 2015 event, FRB 110523, was discovered in data from the Green Bank dish in West...

An Exoplanet Changing Over Time

by Paul Gilster | Feb 23, 2016 | Exoplanetary Science | 15 Comments

Keep your eye on a program called the Hubble Cloud Atlas. This is a collaboration between fourteen exoplanet researchers around the globe that is intent on creating images of exoplanets using the Hubble Space Telescope. But while we've been able to directly image a small number of planets before now, the Cloud Atlas project brings a new twist. The plan is to create time-resolved images that can tease out details about planetary atmospheres. The test case is the planet 2M1207b, about 160 light years out in the constellation Centaurus. Infrared imaging made it possible to directly observe this planet in April of 2004, a task accomplished by researchers from the European Southern Observatory using data from the Very Large Telescope at Paranal (Chile). What we know about this planet makes it a formidable -- and definitely uninhabitable -- object, one with a surface temperature in the 1700 K range. Image: The 2M1207 star system, showing the faint red object 2M1207b, a planet four times...

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In Centauri Dreams, Paul Gilster looks at peer-reviewed research on deep space exploration, with an eye toward interstellar possibilities. For many years this site coordinated its efforts with the Tau Zero Foundation. It now serves as an independent forum for deep space news and ideas. In the logo above, the leftmost star is Alpha Centauri, a triple system closer than any other star, and a primary target for early interstellar probes. To its right is Beta Centauri (not a part of the Alpha Centauri system), with Beta, Gamma, Delta and Epsilon Crucis, stars in the Southern Cross, visible at the far right (image courtesy of Marco Lorenzi).

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