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GRB Burst Tests Special Relativity

by Paul Gilster | Oct 30, 2009 | Exotic Physics | 23 Comments

Gamma ray bursts (GRBs) are much in the news. GRB 090423 turns out to be the most distant explosion ever observed, an event that occurred a scant 630 million years after the Big Bang. We're detecting the explosion of a star that occurred when the first galaxies were beginning to form. Current thinking is that the earliest stars in the universe were more massive than those that formed later, and astronomers hope to use GRB events to piece together information about them. GRB 090423 was evidently not the death of such a star, but more sensitive equipment like the Atacama Large Millimeter/submillimeter Array (ALMA) will soon be online (ALMA within three years) to study more distant GRBs and open up more from this early epoch. And then there's all the fuss about Einstein. The Fermi Gamma Ray Space Telescope, which has already captured more than a thousand discrete sources of gamma rays in its first year of observations, captured a burst in May that is tagged GRB 090510. Evidently the...

Advancing Action at NASA (and Beyond)

by Paul Gilster | Oct 29, 2009 | Culture and Society | 15 Comments

Back in 2003, I went to Glenn Research Center in Cleveland for a meeting with Marc Millis. The Breakthrough Propulsion Physics project that Millis headed had recently been shut down, but I had the sense that this might be temporary and was eager to talk to him about what BPP had thus far accomplished. My feeling about its reinstatement proved to be inaccurate, and just four years later, NASA also shut down its Institute for Advanced Concepts in Atlanta, leaving a conceptual void at the agency's core. Two Takes on Futuristic Studies NIAC and BPP were working opposite sides of the street even when both were fully funded. Whereas NIAC took a more short-term perspective, funding research projects with implications for space in the not distant future, BPP plunged into far more theoretical terrain, looking at everything from engineering the vacuum to wormhole physics and the potential for warp drive. You could trace some of this impulse back to the Vision-21 gathering in 1990 at what was...

NIAC Redux: A Visionary Future

by Paul Gilster | Oct 28, 2009 | Culture and Society | 8 Comments

The decision to close NASA's Institute for Advanced Concepts (NIAC) in 2007 was a blow to the research community, especially given the fact that the agency's Breakthrough Propulsion Physics project had been shelved some years previously. These twin haymakers to the study of futuristic technologies emphasized the lack of support for spending money on anything beyond the near-term, and reminded us that forty years after the fact, we still can't manage even a return to the Moon. NIAC seemed to offer better. Established in 1998, the Atlanta-based program offered non-NASA scientists a chance to delve into revolutionary space and aeronautics concepts, with a multi-tiered funding strategy and the potential for the best ideas to receive further study within the agency (or in a number of cases, from sources outside it). NIAC was hardly a budget-breaker, totalling $36.2 million spread across the nine years of its existence. A New Report Looks at Invigorating Research Now we have a new report...

Habitable Moons and Kepler

by Paul Gilster | Oct 27, 2009 | Exoplanetary Science | 26 Comments

While we've looked several times in these pages at David Kipping's work on exomoons, the investigation of moons much closer to home reminds us that finding a habitable satellite of another planet may not be out of our reach. After all, we're gaining insights into possible habitats for at least microbial life on (or in) places like Europa and Enceladus, and speculations about similar biospheres within some Kuiper Belt objects also keep them in contention. So what about a habitable moon around a distant gas giant? Kipping (University College London) has now gone to work on the question in relation to the Kepler space telescope. His findings are striking: A Saturn-sized planet in the habitable zone of an M-dwarf star would allow the detection of an exomoon down to 0.2 Earth masses. Image: A habitable exomoon would offer an exotic vista, a view that may be more common in the galaxy than we have previously imagined. Credit: Dan Durda. Now that sounds unusual, given that Kepler can't find...

Refining the Deuterium Starship

by Paul Gilster | Oct 26, 2009 | Advanced Rocketry | 25 Comments

by Adam Crowl Adam Crowl has been following Friedwardt Winterberg's fusion concepts for some time, and now weighs in with a look at Winterberg's latest thinking on the use of deuterium reactions in advanced propulsion designs. If fusion is our best bet for interstellar missions, we need to get past the limitations of deuterium/tritium, which produces a neutron flux of such proportion that a manned mission would pay a huge penalty in shielding. Winterberg's ideas on thermonuclear deuterium reactions offer a technique with high exhaust velocities, one with interesting echoes of Project Orion. Back in the 1960s Robert Enzmann imagined immense fusion-propelled starships which saved tankage mass by storing frozen fusion fuel - chiefly deuterium - as a huge frozen ball. Enzmann and his co-workers eventually found that deuterium isn't a very strong solid and a tank of some sort would be needed for mechanical support under acceleration. Even so attaching a starship to a great big mass of...

Notes & Queries 10/23/09

by Paul Gilster | Oct 23, 2009 | Culture and Society | 54 Comments

On Perfect Mornings Stan Getz' version of 'Early Autumn' is to me the definitive take on this standard, though so many fine musicians have attempted it that I'm sure to draw an argument from jazz buffs. But every year when the leaves have just begun to turn, the Getz interpretation runs through my mind on my morning walk, as it did today. A fine breeze was in the air and it carried the scent of approaching rain. The leaves wrapped the scene in muted gold and vermilion, not as bright as in some years, but lovely just the same. So perfect was the moment that it called up a quote from J.B Priestley that I only imperfectly remembered. When I got back to my desk, I looked up the exact wording: I have always been delighted at the prospect of a new day, a fresh try, one more start, with perhaps a bit of magic waiting somewhere behind the morning. Early CoRoT Results Available Early results from CoRoT are now appearing in a special issue of Astronomy & Astrophysics (Vol. 506 No. 1), running...

Updating the Dinosaur Killer

by Paul Gilster | Oct 22, 2009 | Asteroid and Comet Deflection | 6 Comments

Sankar Chatterjee (Texas Tech) and a team of researchers have been looking at something known as the Shiva basin, that area west of India that is heavily laden with oil and gas resources. Chatterjee believes the Shiva basin is in fact a huge, multi-ringed impact crater, one caused by a bolide perhaps as much as 40 kilometers in diameter, big enough, as the scientist says, to create its own tectonics. The supposed dinosaur killer impactor in the Yucatan, by contrast, is thought to have been between eight and ten kilometers wide. Is Shiva basin the crater left by the actual extinction event? Mostly submerged, Shiva's outer rim forms a 500-kilometer ring with a central peak extending some three miles from the ocean floor. One result of such a strike, if the team's theories hold up, is that the volcanic eruptions at the nearby Deccan Traps may well have been enhanced, not to mention the ensuing formation of the Seychelles Islands, which would have broken off the Indian tectonic plate....

HD 209458b: Comparing Exoplanet Atmospheres

by Paul Gilster | Oct 21, 2009 | Exoplanetary Science | 3 Comments

We're making progress at detecting the signatures of organic chemicals on other planets. Mark Swain (JPL) and team have already made a name for themselves in this arena by their detection of carbon dioxide in the atmosphere of the 'hot Jupiter' HD 189733b, which followed earlier Hubble and Spitzer observations that revealed water vapor and methane there. Now they've used the same observatories to study another hot gas giant, HD 209458b, which orbits a star 150 light years away in Pegasus. The result: A detection of basic materials necessary for life. Swain spells out what the team found and its significance: "[HD 209458b is] the second planet outside our solar system in which water, methane and carbon dioxide have been found, which are potentially important for biological processes in habitable planets. Detecting organic compounds in two exoplanets now raises the possibility that it will become commonplace to find planets with molecules that may be tied to life." No one is suggesting...

Beyond Darwin: The Future of Exoplanet Imaging

by Paul Gilster | Oct 20, 2009 | Exoplanetary Science | 20 Comments

After we've found an Earth-like planet with a potential for life, what further things can we do to investigate it? A team led by Jean Schneider (Paris Observatory) asks this question in a new paper, speculating that there are things a technological society does that leave a sure trace. Given the right instruments (no small requirement), we might look, for example, for Carbon Fluoro Compounds (CFCs). Well known for their damaging effects on our ozone layer, CFCs absorb infrared light at characteristic wavelengths, making their signature a revealing one. Spotting an Extraterrestrial 'Techno-Signature' Schneider calls markers like this 'techno-signatures' (as opposed to the more familiar 'bio-signatures'). They're spectral features that can't be explained by complex organic chemistry. Find CFCs in the atmosphere of a distant world and you've got a snapshot of technological chemical synthesis at work. We might speculate as to whether the average civilization produces CFCs in abundance,...

HARPS Bags 32 New Exoplanets

by Paul Gilster | Oct 19, 2009 | Exoplanetary Science | 17 Comments

More than 75 exoplanets in thirty different planetary systems is an impressive score, and that's what HARPS has compiled since its installation in 2003. The High Accuracy Radial Velocity Planet Searcher is the spectrograph for the European Southern Observatory's 3.6-meter telescope at La Silla (Chile). Built by a consortium led by Michel Mayor (Geneva Observatory), HARPS does its work by measuring the minute changes in a star's radial velocity that flag the presence of an unseen companion. Most of the roughly four hundred exoplanets discovered to date have been found through radial velocity methods. The figure of 400 includes the latest results from HARPS, which is back in the news with the announcement of 32 new exoplanets, found as part of a five year program using observing time given to the HARPS consortium in return for building the instrument. One of the new worlds is Gliese 667 Cb [see andy's note below], a six Earth-mass planet in a triple star system. The planets announced...

‘Paradise Regained’: A Timely Optimism

by Paul Gilster | Oct 17, 2009 | Culture and Society | 4 Comments

There is welcome news from Greg Matloff. His new book, written with the artist C Bangs and physicist Les Johnson (NASA MSFC) will be published by Springer/Praxis in December. Following on the success of Solar Sails, the latest is Paradise Regained, a look at how we might use the resources of the Solar System to alleviate environmental problems here on Earth. Here's an absorbing video presentation on the book. [youtube yes7-rPQSjI 500 375] Extending Earth's resource base beyond our atmosphere, and in the process protecting the Earth from asteroid and comet impact, is essential as we gradually become not just a terrestrial but, in Matloff's words, a cosmic species. "If we are wise enough to work together on this, terrestrial life in the Solar System can live as long as the Sun," says the author, an optimism that should resonate with Centauri Dreams readers.

Reshaping the Solar System

by Paul Gilster | Oct 16, 2009 | Interstellar Medium | 3 Comments

Yesterday's story on IBEX is now complemented by images from the Ion and Neutral Camera, part of the Magnetospheric Imaging Instrument on the Cassini orbiter. The Cassini data confirm the fact that the heliosphere isn't shaped the way we've always thought. The assumption up to now has been that the collision of the solar wind with the interstellar medium would create a foreshortened nose in the direction of the Solar System's motion, and an elongated tail in the opposite direction. Both IBEX and Cassini argue otherwise. Stamatios Krimigis (Applied Physics Lab, Laurel, MD) notes the import of these findings: "These images have revolutionized what we thought we knew for the past 50 years; the sun travels through the galaxy not like a comet but more like a big, round bubble. It's amazing how a single new observation can change an entire concept that most scientists had taken as true for nearly fifty years." Amazing and invigorating, for we're opening up serious new ground here. Put...

A Surprise at the Termination Shock

by Paul Gilster | Oct 15, 2009 | Interstellar Medium | 5 Comments

Findings that are outside our expectations seem par for the course as we explore the Solar System. From the volcanoes of Io to the geysers of Enceladus, unusual things show up with each new mission. Why should IBEX be any different? The Interstellar Boundary Explorer is the first spacecraft expressly designed to study what happens at the edge of the Solar System, where nearby space meets the interstellar medium. The 'bubble' around the Sun called the heliosphere comes about as charged particles in the solar wind move continuously away from the Sun. Although IBEX is far from the heliopause (it's orbiting the Earth with an apogee of 322,000 kilometers and a perigee of 16,000 kilometers), its instruments are tuned to study energetic neutral particles (ENAs) swept up by the solar wind in the boundary between the edge of the heliosphere and interstellar space beyond. IBEX has been mapping this area since last October. And here comes the surprise, as explained by IBEX principal...

Adrift on Ligeia Mare

by Paul Gilster | Oct 14, 2009 | Outer Solar System | 24 Comments

Imagine a boat from Earth drifting across an alien sea. Something like that could happen as early as 2022 if Ellen Stofan (Proxemy Research) can talk the powers that be into the venture. Stofan envisions a new mission to Titan, the only other place in the Solar System known to have bodies of liquid on its surface. The methane and ethane lakes revealed by Cassini show some bodies as large as the Black Sea or the Great Lakes of North America. Stofan's target: Ligeia Mare or Kraken Mare, two of the larger possibilities revealed by the orbiter. Image: Radar data from Cassini allowed the creation of this artificially colorized view of Ligeia Mare, with liquid methane/ethane shown in blue. Credit: NASA/JPL/USGS. What an interesting off-shoot from the conventional rover concept, but then, Titan seems to inspire such things. Various types of airship designs have been put forward for studying the Saturnian moon, and at the Aosta conference in July, Giancarlo Genta described the workings of a...

TNO Project: Mapping the Unexplored

by Paul Gilster | Oct 13, 2009 | Outer Solar System | 4 Comments

Back when I was a kid I found an old atlas that had been on the family shelves since the early 1900's. I used to browse through it looking at all the places that had changed. The map of eastern Europe was, as you can imagine, a far cry from what it later became, with the pre-World War I world vividly sketched in those musty pages. But what really caught my eye was one of the maps of South America, showing an area of Brazil that was still marked 'unexplored.' It was the only such place I could find on any of the maps, and it filled my adolescent head with thoughts of adventure. I wish I had that atlas nearby to scan from, but the image below gets across the feel of those old maps. Henry M. Stanley I'm not, but exploration has huge appeal, and to get the pure product today, we have to move into space. Out there most everything could be marked 'unexplored.' Sure, we're getting to know the planets, but we've only had a few missions beyond Mars, have yet to see Pluto/Charon close up, and...

A Test for Exotic Propulsion?

by Paul Gilster | Oct 12, 2009 | Exotic Physics | 21 Comments

Can we calculate the gravitational field of a mass moving close to the speed of light? Franklin Felber (Starmark Inc) believes he can, with implications for propulsion. Back in 2006 we looked briefly at Felber's work, describing what the physicist believes to be a repulsive gravitational field that emerges from his results. Felber discussed the matter at the Space Technology and Applications International meeting that year, where he presented his calculations of the 'relativistically exact motion of a payload in the gravitational field of a source moving with constant velocity.' Above a certain critical velocity, Felber believes, any mass will gravitationally repel other masses, an effect that is twice as strong in the forward direction of motion, but also works in the backward direction. An object lying in the narrow beam thus produced could be accelerated quickly and with little stress. He described the effect in a paper he submitted in 2005 to the arXiv site: At radial approach or...

Asteroids: A Near Miss, An Informative Hit

by Paul Gilster | Oct 9, 2009 | Asteroid and Comet Deflection | 8 Comments

New observations of asteroid Apophis, reported at the Division for Planetary Sciences meeting in Puerto Rico, indicate that the chances of its striking the Earth in 2036 must be recalculated, diminishing from roughly 1 in 45,000 to 1 in 250,000. There goes one disaster scenario, but enter another: An impact possibility exists for the year 2068. Says David Tholen (University of Hawaii): "Our new orbit solution shows that Apophis will miss Earth's surface in 2036 by a scant 20,270 miles, give or take 125 miles. That's slightly closer to Earth than most of our communications and weather satellites." Too close for comfort, but a miss is a miss. Apophis reappears from behind the Sun in 2010 and is sure to be the object of even more intense scrutiny in years to come. But bear in mind that, just as we were able to refine our figures for the 2029 and 2036 encounters, we will probably be able to reduce the 1 in 333,000 chance now calculated for Apophis to actually strike in 2068. Image:...

An Oxygen-Rich Europan Ocean?

by Paul Gilster | Oct 8, 2009 | Outer Solar System | 14 Comments

Long-time Centauri Dreams readers already know of my admiration for Richard Greenberg's work on Europa, admirably summarized in his 2008 title Unmasking Europa: The Search for Life on Jupiter's Ocean Moon (Copernicus). It's a lively and challenging book, one which Greenberg used to take sharp issue with many of his colleagues, and although he played this aspect of the work down in a phone conversation when I reviewed the book, the animated back and forth makes for a fascinating look at how planetary science gets done. In his book, Greenberg argues forcefully that the thickness of Europa's ice is unlikely to be more than a few kilometers, and that its active resurfacing would make it possible for life-forms below the ice to occasionally be carried above it. That would be good news for our hopes of detecting life, of course, for it would obviate the need to drill through the ice sheet. A spacecraft's electronics might not last long given radiation levels this close to Jupiter, but...

Planetary Habitability Quantified

by Paul Gilster | Oct 7, 2009 | Astrobiology and SETI | 30 Comments

Habitability is always a matter of definition. Is it a measure of suitability for human life? Or do we take the larger astrobiological view that it's based on suitability for microbial life, in which case we go from a narrowly defined habitable zone here in our Solar System to one that could potentially stretch from the upper atmosphere of Venus to the suspected subsurface aquifers on some Kuiper Belt objects. But these qualitative definitions have thus far lacked a quantitative counterpart, a method to quantify and compare potentially living worlds. The matter has drawn the attention of Abel Mendez (University of Puerto Rico, Arecibo), who discussed his quantitative evaluation of planetary habitability at the Division for Planetary Sciences meeting this week in Fajardo, Puerto Rico. One of his results stands out immediately. Using finely tuned planetary models, Mendez found that among Mars, Venus, Europa, Titan and Enceladus, the latter has the highest subsurface habitability. That...

Dark Energy’s Elusive Signature

by Paul Gilster | Oct 6, 2009 | Exotic Physics | 6 Comments

It's odd to think that there would be a connection between the large-scale structure of the universe and what we hope to achieve with deep space propulsion. But figuring out how things work on the largest scale may offer us valuable clues about what is possible and what is not. If we understand correctly how gravity works at the macro scale, then the evidence for 'dark energy' seems persuasive. Something is causing the universe not only to expand but to accelerate its expansion, and that something must operate against the force of gravity, which ought to be slowing the process down. Which brings us to BOSS, the Baryon Oscillation Spectroscopic Survey, now beginning its operations after taking first light on the night of September 14-15. A part of the Sloan Digital Sky Survey III, BOSS will use the 2.5-meter telescope at Apache Point Observatory in New Mexico to measure the spectra of 1.4 million galaxies and 160,000 quasars by 2014. Out of this we should derive the most accurate data...

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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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