No Catastrophic Collision at KIC 8462852

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,...

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Will We Stop at Mars?

In the heady days of Apollo, Mars by 2000 looked entirely feasible. Now we're talking about the 2030s for manned exploration, and even that target seems to keep receding. In the review that follows, Michael Michaud looks at Louis Friedman's new book on human spaceflight, which advocates Mars landings but cedes more distant targets to robotics. So how do we reconcile ambitions for human expansion beyond Mars with political and economic constraints? A career diplomat whose service included postings as Counselor for Science, Technology and Environment at U.S. embassies in Paris and Tokyo, and Director of the State Department's Office of Advanced Technology, Michael is also the author of Contact with Alien Civilizations (Copernicus, 2007). Here he places the debate over manned missions vs. robotics in context, and suggests a remedy for pessimism about an expansive future for Humankind. by Michael A.G. Michaud Many people in the space and astronomy communities will know of Louis Friedman,...

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A Cometary Solution for KIC 8462852?

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....

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Huge Flares from a Tiny Star

Just a few days ago we looked at evidence that Kepler-438b, thought in some circles to be a possibly habitable world, is likely kept out of that category by flare activity and coronal mass ejections from the parent star. These may well have stripped the planet’s atmosphere entirely (see A Kepler-438b Caveat - and a Digression). Now we have another important study, this one out of the Harvard-Smithsonian Center for Astrophysics, taking a deep look at the red dwarf TVLM 513–46546 and finding flare activity far stronger than anything our Sun produces. Led by the CfA’s Peter Williams, the team behind this work used data from the Atacama Large Millimeter/submillimeter Array (ALMA), examining the star at a frequency of 95 GHz. Flares have never before been detected from a red dwarf at frequencies as high as this. Moreover, although TVLM 513 is just one-tenth as massive as Sol, the detected emissions are fully 10,000 times brighter than what our star produces. The four-hour observation...

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The 3 Most Futuristic Talks at IAC 2015

Justin Atchison’s name started appearing in these pages all the way back in 2007 when, in a post called Deep Space Propulsion via Magnetic Fields, I described his work at Cornell on micro-satellites the size of a single wafer of silicon. Working with Mason Peck, Justin did his graduate work on chip-scale spacecraft dynamics, solar sails and propulsion via the Lorentz force, ideas I’ve tracked ever since. He’s now an aerospace engineer at the Johns Hopkins University Applied Physics Laboratory, where he focuses on trajectory design and orbit determination for Earth and interplanetary spacecraft. As a 2015 NIAC fellow he is researching technologies that enable asteroid gravimetry during spacecraft flybys. In the entry that follows, Justin reports on his trip to Jerusalem for this fall’s International Astronautical Congress. by Justin A. Atchison Greetings. I’m Justin Atchison, an aerospace engineer at the Johns Hopkins University Applied Physics Laboratory. I’m proud to have previously...

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The Cereal Box

"No matter how these issues are ultimately resolved, Centauri Dreams opts for the notion that even the back of a cereal box may contain its share of mysteries." I wrote that line in 2005, and if it sounds cryptic, read on to discover its origins, ably described by Christopher Phoenix. I first encountered Christopher in an online discussion group made up of physicists and science fiction writers, where his knack for taking a topic apart always impressed me. A writer whose interest in interstellar flight is lifelong, he is currently turning his love of science fiction into a novel that, he tells me "incorporates some of the ideas we talk about on Centauri Dreams as a background setting." Today's essay examines the ideas of a physicist who dismissed the idea of interstellar flight entirely, while using a set of assumptions Christopher has come to challenge. by Christopher Phoenix "All this stuff about traveling around the universe in space suits -- except for local exploration which I...

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Directly Imaging a Young ‘Jupiter’

Centauri Dreams continues to follow the fortunes of the Gemini Planet Imager with great interest, and I thank Horatio Trobinson for a recent note reminding me of the latest news from researchers at the Gemini South installation in Chile. The project organized as the Gemini Planet Imager Exoplanet Survey is a three-year effort designed to do not radial velocity or transit studies but actual imaging of young Jupiters and debris disks around nearby stars. Operating at near-infrared wavelengths, the GPI itself uses adaptive optics, a coronagraph, a calibration interferometer and an integral field spectrograph in its high-contrast imaging work. Launched in late 2014, the GPIES survey has studied 160 targets out of a projected 600 in a series of observing runs, all the while battling unexpectedly bad weather in Chile. Despite all this, project leader Bruce Macintosh (Stanford University), the man behind the construction of GPI, has been able to announce the discovery of the young 'Jupiter'...

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A Kepler-438b Caveat (and a Digression)

Before we go interstellar, a digression with reference to yesterday's post, which looked at how we manipulate image data to draw out the maximum amount of information. I had mentioned the image widely regarded as the first photograph, Joseph Nicéphore Niépce's 'View from the Window at Le Gras.' Centauri Dreams regular William Alschuler pointed out that this image is in fact a classic example of what I'm talking about. For without serious manipulation, it's impossible to make out what you're seeing. Have a look at the original and compare it to the image in yesterday's post, which has been processed to reveal the underlying scene. Image: New official image of the first photograph in 2003, minus any manual retouching. Joseph Nicéphore Niépce's View from the Window at Le Gras. c. 1826. Gernsheim Collection Harry Ransom Center / University of Texas at Austin. Photo by J. Paul Getty Museum. And here again is the processed image, a much richer experience. The...

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Pluto and How We See It

As I did after yesterday's post, I occasionally get requests for pictures of objects in natural color, as opposed to significantly enhanced images (at various wavelengths) designed to tease out structure or detail. Here are Pluto and Charon as seen by New Horizons' LORRI (Long Range Reconnaissance Imager), with color data supplied by the Ralph instrument. The images in this composite are from July 13 and 14 and according to JHU/APL, "...portray Pluto and Charon as an observer riding on the spacecraft would see them." For those interested, Jenna Garrett wrote a fine piece for WiReD last summer called What We're Really Looking at When We Look at Pluto that goes into the instrumentation aboard New Horizons and discusses the philosophical issues separating what we see from what is really there. Let me quote briefly from this: It's not hard for a photographer to understand why you'd question actually seeing Pluto—the same question has nagged photographers since Nicéphore...

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Pluto’s Unexpected Complexities

Keeping up with a site like this can be a daunting task, especially when intriguing papers can pop up at any time and announcements of new finds by our spacecraft come in clusters. But site maintenance itself can be tricky. Recently Centauri Dreams regular Tom Mazanec wrote in with a project to be added to the links on the home page and before long, with my encouragement, he had sent a number of solid suggestions on exoplanet projects both Earth- and space-based, most of which have now been added. My thanks to Tom and all those who have at various times caught a broken link or added a suggestion for new links or stories. We begin the week looking at work discussed at the Division for Planetary Sciences meeting in Maryland, starting with the continuing bounty coming in from New Horizons. I always like to quote Alan Stern, because as principal investigator for New Horizons, he is not only its chief spokesman but the guiding force that saw this mission become a reality. And I think he's...

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The Initiative for Interstellar Studies: A Three Year Update

Kelvin Long is chief editor of the Journal of the British Interplanetary Society and the author of Deep Space Propulsion (Springer, 2011). A founder and first project leader of Project Icarus, the ongoing re-design of the Project Daedalus starship, Kelvin is also a co-founder of the non-profit Icarus Interstellar. He now serves as executive director of the Institute for Interstellar Studies, an organization whose mission ('Scientia ad Sidera: Knowledge to the Stars') he describes in the following essay. by Kelvin F. Long The Initiative for Interstellar Studies (i4is) is a not-for-profit foundational institute incorporated in the United Kingdom with the mandate to develop interstellar capabilities. We at the initiative just successfully passed our third anniversary since our founding. We began work in August 2012 and went live on the 12th September 2012. Shortly after, we ratified our purpose through our innovative logo, and our mission and vision statements. And today we are focused...

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The Most Distant Dwarf Planet Yet

Back in the days when Clyde Tombaugh was using a blink comparator to search for 'Planet X,' finding a new object in the outer Solar System was highly unusual. Uranus had been found in 1781, Neptune in 1846, and I suppose I should add Ceres in 1801, although it's a good deal closer than the other two. The real point is that the Solar System seemed straightforward in Clyde Tombaugh's day. There were eight planets and an asteroid belt. It wouldn't be until 1943 that Kenneth Edgeworth argued that the outer system might have 'a very large number of comparatively small bodies,' with Gerard Kuiper publishing his own speculations in 1951. Estonian astronomer Ernst Öpik first described what we now know as the Oort Cloud in 1932, with Jan Oort, a Dutch astronomer, reviving the idea in 1950. The Oort Cloud was a way to explain why comets behave the way they do. Oort believed that there must be a cometary 'reservoir' far away from the Sun -- he chose 20,000 AU as a likely range because of the...

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A Relatively Nearby Earth-Sized Planet

Given my abiding interest in red dwarf stars and the planets that circle them, I always keep an eye on what's happening with the MEarth project. Two arrays of robotically controlled telescopes are involved in MEarth (pronounced 'mirth'), one at the Fred Lawrence Whipple Observatory on Mt. Hopkins (AZ), the other a cluster of eight at the Cerro Tololo Inter-American Observatory in Chile. Both these arrays are controlled from MEarth's offices in Cambridge (MA). MEarth is all about observing nearby M-dwarfs in the hunt for Earth-class planets. My fascination in these stars is simply a result of the numbers. We've learned that M-dwarfs comprise as much as 80 percent of the stars in the Milky Way. Earth is not, in other words, orbiting the most common type of star out there. We also know that M-dwarfs host planets. If we learn that conditions on such worlds can support life, then we've dramatically expanded the search space for astrobiology. The prospect of a living world, probably...

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Quantifying KIC 8462852 Power Beaming

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...

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Alpha Centauri Planet Reconsidered

Finding a habitable world around any one of the three Alpha Centauri stars would be huge. If the closest of all stellar systems offered a blue and green target with an atmosphere showing biosignatures, interest in finding a way to get there would be intense. Draw in the general public and there is a good chance that funding levels for exoplanet research as well as the myriad issues involving deep space technologies would increase. Alpha Centauri planets are a big deal. The problem is, we have yet to confirm one. Proxima Centauri continues to be under scrutiny, but the best we can do at this point is rule out certain configurations. It appears unlikely, as per the work of Michael Endl (UT-Austin) and Martin Kürster (Max-Planck-Institut für Astronomie), that any planet of Neptune mass or above exists within 1 AU of the star. Moreover, no 'super-Earths' have been detected in orbits with a period of less than 100 days. This doesn't rule out planets around Proxima, but if they are there,...

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SETI: No Signal Detected from KIC 8462852

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...

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A 3D Look at GJ 1214b

An old friend used to chide me about the space program, asking good-naturedly enough why it mattered to travel nine years to get to a place like Pluto (this was not long after the New Horizons launch). 'Just another rock,' he would say. 'Why go all that way to look at just another rock?' Although we had many disagreements, Abe was one of the shrewdest people I've ever known. I had met him when he was in his sunset years, but in his prime he had run a large financial operation, been the subject of a story on the front page of the Wall Street Journal and had made a serious fortune in real estate speculation. So what about this 'just another rock' meme? Abe died a few years back but I think about him in relation to things like yesterday's story on Charon. The point is, it's not just another rock. It's this particular rock. And maybe it's not a rock at all; maybe it's a ball of icy slush. And maybe, as we've learned, it's a seriously interesting thing that surpasses expectation. Each...

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Unusual Crater on Charon

Another surprise from New Horizons, in a year which will surely see a few more before it ends. After all, we have a long flow of data ahead as the spacecraft continues to return the information it gathered during the July flyby of Pluto/Charon. Now we focus on Charon and the crater being called Organa, which produced an anomaly when scientists studied the highest resolution infrared compositional scan of the moon available. This crater and some of the surrounding materials show infrared absorption at about 2.2 microns, indicating frozen ammonia. Not far away on Charon's Pluto-facing hemisphere is Skywalker crater, which under infrared scrutiny shows the same composition as the rest of Charon's surface. Here water ice -- not ammonia -- dominates. As this JHU/APL news release notes, ammonia absorption was first detected on Charon as far back as 2000, but what we're seeing here is unusually concentrated. In any case, why is Organa so different from Skywalker and the rest of Charon's...

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Exoplanetology Beyond Kepler

Useful synergies continue to emerge among our instruments as we ponder the future of exoplanet studies. Consider the European Space Agency’s PLATO mission (PLAnetary Transits and Oscillations of stars). Operating from the L2 Lagrangian point, PLATO will use 34 telescopes and cameras on a field of view that includes a million stars, using transit photometry, as Kepler did, to find planetary signatures. Working at optical wavelengths, PLATO will look for nearby Earth-sized and ‘super-Earth’ planets in the habitable zone of their stars. This mission is scheduled to be launched in 2024, an interesting date because it’s also the year that the European Extremely Large Telescope (E-ELT) is scheduled to see first light. Huge new installations like these, although ground-based, are so powerful that they should be able, with the help of adaptive optics, to study planetary atmospheres on the PLATO-discovered planets. Thus we get the best of both worlds, with repairable and upgradable ground...

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Voyager Update: Probing the Boundary

I always feel that my day starts right when a story involving the Voyagers crosses my desk. The scope, the sheer audacity of these missions in their day cheers me up, and the fact that they are still communicating with us is a continual cause for celebration. With Voyager 1 now moving beyond the heliosphere, we've got an interstellar craft on our hands, one that's telling us a good deal about the perturbed regions through which it moves. Every day that the Voyagers stay alive is a triumph for an inquisitive and exploring species, and one day we'll be launching their successor, targeting the local interstellar medium with instruments designed for the task. Image: This artist's concept shows NASA's Voyager spacecraft against a backdrop of stars. Credit: NASA/JPL-Caltech. The heliosphere is that 'bubble' blown by the particles of the Sun's solar wind in surrounding interstellar space. As such, it's a moving and malleable thing, flexing, flowing, contracting here, expanding there...

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Charter

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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