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Astrometry Bags a ‘Cold Jupiter’

by Paul Gilster | May 29, 2009 | Exoplanetary Science | 29 Comments

We're now up to 347 detected exoplanets around 293 stars. The latest find turns out to be intriguing on several counts. VB 10 is a red dwarf about 20 light years away in the constellation Aquila. Its newly detected planet is a gas giant with a mass six times that of Jupiter, a 'cold Jupiter' not so different from our own. Interestingly, although the star is considerably more massive, both planet and star should have roughly the same diameter. Image: This artist's diagram compares our solar system (below) to the VB 10 star system. Astronomers successfully used the astrometry planet-hunting method for the first time to discover a gas planet, called VB 10b, around a very tiny star, VB 10. All of the bodies in this diagram are shown in circular insets at the same relative scales. Astrometry involves measuring the wobble of a star on the sky, caused by an unseen planet yanking it back and forth. Because the VB 10b planet is so big relative to its star, it really tugs the star around. The...

Radio Supernovae and the ATA

by Paul Gilster | May 28, 2009 | Deep Sky Astronomy & Telescopes | 6 Comments

We think of the Allen Telescope Array, currently comprising only 42 of the 350 radio dishes planned, as a SETI instrument, capable of digging faint signals out of a wider field of stars than ever before. But the ATA is also engaged in an astrophysical survey of the sky at radio wavelengths, one that will look for radio bursts from supernovae. A glimpse of what it is looking for has just been reported in M82, a small irregular galaxy about twelve million light years from Earth. We're talking about a so-called 'radio supernova,' an exploding star undetectable by optical or X-ray telescopes. The new object is the brightest supernova seen in radio wavelengths in the last twenty years, and one of only a few dozen of its kind observed so far. And while the ATA will help us locate future radio objects of its kind, this one was found with the Very Large Array in New Mexico, and later confirmed through the NRAO's Very Long Baseline Array. Image (click to enlarge): Zooming into the center of...

Maps of an Alien Earth

by Paul Gilster | May 27, 2009 | Exoplanetary Science | 7 Comments

Anyone who thought the Deep Impact mission was over when the spacecraft drove an impactor into comet Tempel 1 some four years ago has been given a lesson in the strategy of extended missions. Now heading for a flyby of comet Hartley 2 (late in 2010), Deep Impact is also doing yeoman work in the study of extrasolar planets. That phase of the mission is called Extrasolar Planet Observations and Characterization (EPOCh), but the spacecraft housing both investigations is now referred to as EPOXI. If the acronyms can be confusing, the latest news from EPOXI is straightforward, and encouraging. A paper slated for summer publication in the Astrophysical Journal reports on the spacecraft's observations of our own planet, made in 2008 when it was between 17 and 33 million miles from Earth. The idea was to tune up our capabilities at observing distant planets, using spectral information to map the distribution of continents and oceans. EPOXI's High Resolution Imager thus set up a trial of...

Growing the Interstellar Probe

by Paul Gilster | May 26, 2009 | Autonomy and Robotics | 20 Comments

Centauri Dreams reader Brian Koester passed along a link to a provocative video last month that spurs thoughts about the nature of interstellar probes. The video is a TED talk delivered by Paul Rothemund in 2007. For those not familiar with it, TED stands for Technology, Entertainment, Design, a conference that began in 1984 and now brings together interesting scientific figures whose challenge is to give the best talk they can on their specialty within the span of eighteen minutes. I've been pondering Rothemund's talk for some time. You can call this Caltech bioengineer a 'DNA origamist,' meaning that he is exploring ways to fold DNA into shapes and patterns. As becomes clear in his presentation, folding DNA into 'smiley' faces or maps has a certain wow factor, but once you get past the initial wonder of working at this level, you begin to appreciate how research in DNA nanotechnology points toward self-assembling devices that can be built at the micro-scale. Molecular Computing to...

Creating Stars in the Laboratory

by Paul Gilster | May 25, 2009 | Advanced Rocketry | 15 Comments

The 192 lasers of the National Ignition Facility at Lawrence Livermore National Laboratory in California can focus 500 trillion watts of power onto a pellet of hydrogen fuel the size of a pencil eraser. With full-scale experiments slated to begin soon, we'll learn much about the feasibility of nuclear fusion on Earth, hoping to extract more energy from the process than goes into making it happen. The forms of hydrogen at play here are deuterium and tritium, which fuse to form helium. Image: All of the energy of NIF's 192 beams is directed inside a gold cylinder called a hohlraum, which is about the size of a dime. A tiny capsule inside the hohlraum contains atoms of deuterium (hydrogen with one neutron) and tritium (hydrogen with two neutrons) that fuel the ignition process. Credit: National Ignition Facility. Inertial confinement fusion using lasers is a different approach than the magnetic confinement method used at the International Thermonuclear Experimental Reactor (ITER),...

A Dark Matter Collapse near M87?

by Paul Gilster | May 22, 2009 | Deep Sky Astronomy & Telescopes | 8 Comments

When we talk about the diameter of the Milky Way, it's usual to cite a figure of about 100,000 light years. But the much more diffuse halo of stars surrounding the galaxy actually extends almost twice as far. You would expect to find more or less the same situation in other galaxies, but new observations of the giant galaxy M87 have turned up a surprising fact: Its halo of stars is much smaller than expected. It's true that the halo is three times the size of that around the Milky Way, but its diameter of a million light years is still much smaller than anticipated given the size of the parent galaxy. Mysteries like this seem just the thing for the weekend, so consider the possibility, raised in the paper on this work, that the truncated halo is the result of a collapse of dark matter in the Virgo Cluster, where M87 resides. The Virgo Cluster is approximately 50 million light years from us and contains hundreds of galaxies of all descriptions, including spirals like the Milky Way....

Life’s Persistence through the Bombardment

by Paul Gilster | May 21, 2009 | Asteroid and Comet Deflection | 12 Comments

None of us would have wanted to be around during the Late Heavy Bombardment, that frenetic bashing of our planet as the young Solar System worked out its debris problems between 4.1 and 3.8 billion years ago. The Hadean period was a time when enormous asteroids pummeled our world over a span lasting as long as 200 million years, an ongoing series of events one would have assumed lethal for whatever organisms may have evolved by then. But was the Late Heavy Bombardment really the deadly rain we've always assumed? A new paper in Nature questions the idea, basing its results on computer modeling of the Earth's heating during the bombardment. Oleg Abramov and Stephen J. Mojzsis (University of Colorado) argue that our planet's surface would likely have been sterilized during this period, but microbial life below the surface or in underwater conditions would almost certainly have survived. "Our new results point to the possibility life could have emerged about the same time that evidence...

The Hunt for Centauri Planets

by Paul Gilster | May 20, 2009 | Exoplanetary Science | 26 Comments

Finding Earth-like planets around any star would be a stunning feat, and either Kepler or CoRoT may deliver such news before too long. But how much more exciting still if we find a planet like this around a star as close as Centauri B? After all, the Centauri stars are our closest stellar neighbors, close enough (a mere 40 trillion kilometers!) to conjure up the possibility of a robotic mission there and, if we play our propulsion cards right in the future, perhaps a manned trip as well. A Radial Velocity Long Shot But can we pick up the faint signature of a terrestrial world in this system, given that it would be akin to 'detecting a bacterium orbiting a meter from a sand grain -- from a distance of 10 kilometers'? The phrase is Lee Billings', from his fine essay in SEED called The Long Shot, on an ongoing project to do just that. Most radial velocity surveys are spread out over numerous stars, picking off close-in worlds whose traces should be obvious in short periods of time....

Building the Interstellar Message

by Paul Gilster | May 19, 2009 | Astrobiology and SETI | 14 Comments

I'm glad to see the phrasing of the key question used in the SETI Institute's 'Earth Speaks' project. Assuming we one day detect a signal from an extraterrestrial civilization, the Institute asks, 'Should we reply, and if so, what should we say?' Given the apparent ease with which broadcasts to the stars have been made in the last few years, advertising everything from snack foods to movies, this question might easily have been 'What should we say when we respond to an extraterrestrial signal?' When or if? I come down on the side of the 'if' formulation, because the question deserves a global response, one reflecting a broad range of disciplines and perspectives. Such a response takes time to build. Another thing I like about 'Earth Speaks' is that it will give us an interesting take on our own species. The plan here is to encourage people to submit messages, pictures and sounds online, using the Internet to solicit ideas. Fine-Tuning an Interstellar Greeting The site is here, where...

Tau Zero Update

by Paul Gilster | May 18, 2009 | Tau Zero Foundation | 17 Comments

Tau Zero's Kelvin Long seems to be everywhere these days, his most recent publication being a summary of the interstellar sessions at the UK Space Conference, held in early April. You can read that one here, where you'll discover that Long also provides a thorough backgrounder on the Tau Zero Foundation, its goals and vision for the future. Some of these goals are much discussed in these pages -- to make incremental progress toward the robotic and human exploration of the stars by using philanthropic funding to support credible research by Tau Zero 'practitioner' scientists. Other goals include practical ways to expand the public perception of interstellar issues, including supporting students through scholarships, offering educational products, and organizing sessions at established conferences. Echoes naturally arise from the Breakthrough Propulsion Physics project that Marc Millis once managed for NASA, but in fact Tau Zero hopes to take a significantly different course, and one...

My Own Private Star Trek

by Paul Gilster | May 15, 2009 | Culture and Society | 30 Comments

by Jon Lomberg I had no idea when the week started that I would be publishing not one but two essays on Star Trek. But Jon Lomberg was inspired by Athena Andreadis' take on the new movie to write down his own reflections on the series in its many forms. Lomberg's name should be instantly recognizable to this readership. Jon was Carl Sagan's principal artistic collaborator for many years, illustrating Sagan's books and serving as chief artist for COSMOS. He storyboarded many of CONTACT's astronomical animations and designed the cover for the Voyager Interstellar Record, which is now pushing into the heliosheath and bound for true interstellar space. In addition to regular lecturing, Jon is the creator of the remarkable Galaxy Garden in Kona, Hawaii and remains an active astronomical artist in many media. Herewith his thoughts and recollections of Star Trek, Sagan, Roddenberry and more. I wasn't a fan of the series when it first came out. The first episode I recall seeing was in the...

Kepler Observations Begin

by Paul Gilster | May 14, 2009 | Exoplanetary Science | 7 Comments

With the Herschel/Planck telescopes now on their way -- the successful launch took place at 1312 UTC from the European Space Agency's launch pad at Kourou, and the two spacecraft are now on separate trajectories -- we can take a breather to reflect on what a busy time it's been of late for space telescopes. The ongoing Hubble repairs are a fascinating story in and of themselves, but we've also got Kepler to think about as its hunt for Earth-like planets around other stars now gets underway. Shaking out the instrumentation has taken some time, but the Kepler operations team slowed the pace of communications about a week ago to eighteen hours per day, a number that will drop to six as science observations now proceed. For the balance of the mission, according to JPL project manager Jim Fanson, communications will occur only twice per week as Kepler sends home precious data. "Now the fun begins," said William Borucki, Kepler science principal investigator at NASA's Ames Research Center,...

Reflections on the New Star Trek

by Paul Gilster | May 13, 2009 | Culture and Society | 44 Comments

by Athena Andreadis This morning I have the pleasure of introducing my friend Athena Andreadis, who will give us her thoughts on the recent Star Trek film. Dr. Andreadis is Associate Professor of Cell Biology at the University of Massachusetts Medical School, and the author of To Seek Out New Life: The Biology of Star Trek. In her basic molecular neurobiology research, she studies the fundamental gene regulatory mechanism known as alternative splicing. The long-term goal of her research is to understand how the brain works, and contribute to the struggle against mental retardation and dementia. When not conjuring in the lab, Athena writes essays on science and science fiction, while writing her own SF/F fiction, some of which appears at the site Starship Reckless, which she founded. We Now Interrupt Our Regular Programming… … so that, stepping into Paul's hospitable parlor, I can hold forth on the Star Trek reboot (henceforth ST||, for parallel timeline). I assume that...

Thursday Launch for Herschel and Planck

by Paul Gilster | May 12, 2009 | Deep Sky Astronomy & Telescopes | 6 Comments

While we're thinking about space telescopes like the aging but potentially repairable Hubble, let's not forget the launch now scheduled for Thursday from the Guiana Space Centre in Kourou. The European Space Agency's Herschel instrument will be lifted into an orbit 1.5 million kilometers from Earth, stationed at the second Lagrange point (L2) so that Sun, Moon and Earth can all be hidden behind a sunshade to afford the instrument a clear view without disturbance from its celestial neighbors. Image: About 0.5 hours after launch, Herschel separates from the launcher upper stage and starts its cruise to L2 (the second Lagrangian point), situated at about 1.5 million kilometers from Earth. Credit: ESA/D. Ducros, 2009. Along with Herschel goes Planck, also scheduled for the L2 point (the two satellites will separate shortly after launch and reach L2 independently). Herschel is the largest infrared telescope ever launched, with a 3.5-meter primary mirror made of silicon carbide that is...

New Missions for Hubble and Spitzer

by Paul Gilster | May 11, 2009 | Deep Sky Astronomy & Telescopes | 0 Comments

With all eyes on the mission to service the Hubble telescope, it's fascinating to see that technology created for the James Webb Space Telescope is going to be used to enhanced Hubble's Advanced Camera for Surveys (ACS). The particular Application-Specific Integrated Circuit, or ASIC, design in question mirrors that of the Webb instrument and also equipment recently installed at the 2.2-meter University of Hawaii telescope on Mauna Kea, where it is part of the Charge-Coupled Device (CCD) detection system. An ASIC is a small, specialized integrated circuit, and the one about to go into Hubble could be transformative. That's because new spectrographic instruments going into Hubble will work with the repaired and upgraded ACS instrument in the study of dark energy and distant galaxies, a truly enhanced imaging capability for the aging workhorse. The ASIC next goes into space on the Webb telescope, leading one to ponder what a repair mission to that instrument would look like. After all,...

Freezing Out the Dark Energy Field

by Paul Gilster | May 9, 2009 | Exotic Physics | 19 Comments

A testable prediction about dark energy? Such is the promise of a new formulation from Sourish Dutta and Robert Scherrer (Vanderbilt University), whose dark energy model interacts with normal matter and has observable results, including a prediction about the expansion rate of the universe. Astronomical surveys in the next decade should be able to detect the slowdown in the expansion rate predicted by this model, if it exists. Think 'quintessence,' a new field with the unique property that it can act like antigravity, forcing nearby objects to move away from each other rather than pulling them together. The quintessence field as developed by Dutta and Scherer likely went through a phase transition somewhere around 2.2 billion years after the Big Bang. 'Freezing out' as the universe cooled creates a scenario where the energy density of the field remained high until, with the phase transition, it dropped abruptly to a level it retains to this day. Another result: The release of some of...

A Look Back at Star Trek’s Biology

by Paul Gilster | May 8, 2009 | Culture and Society | 21 Comments

The appearance of the new Star Trek film has inspired Athena Andreadis to revisit the epilogue of her 1998 book To Seek Out New Life: The Biology of Star Trek (Random House). Andreadis (University of Massachusetts) is a frequent commenter on issues of space exploration on this and other sites, including her own Astrogator's Logs, where you'll find the updated epilogue. It's well worth reading in the context of how and why we explore. Sharply critical of the Star Trek franchise, Andreadis nonetheless commends its celebration of the human thirst for knowledge, something she believes may be the one thing we have in common with whatever extraterrestrial beings we find out there. This is bracing stuff, even for those of us who leaned more toward Heinlein than Star Trek in our youths. Here, the author speaks about dreaming of possibilities and making them accessible: Scientific understanding does not strip away the mystery and grandeur of the universe; the intricate patterns only become...

New Title on Gravitational Focus Mission

by Paul Gilster | May 7, 2009 | Missions, Research Tools | 14 Comments

Claudio Maccone's new book is out, an extension and re-analysis of the material in two earlier titles that examined the author's innovative ideas on deep space systems. Maccone is best known to Centauri Dreams readers as the major proponent of a mission to the Sun's gravitational focus where, at 550 AU and beyond, a spacecraft could take advantage of lensing properties that would allow detailed observations of distant stars and their planets. The Italian physicist, formerly associated with Alenia Spazio and now working independently on deep space matters, has developed the idea as an interstellar precursor mission loaded with good science. But in the second part of Deep Space Flight and Communications: Exploiting the Sun as a Gravitational Lens (Springer, 2009), he also examines the mathematics of what is known as the Karhunen-Loève Transform (KLT), analyzing the tools that seem to offer the best choices for optimized communications as we eventually develop star-faring capabilities....

EGR: A ‘Hail Mary’ Pass to the Stars

by Paul Gilster | May 6, 2009 | Missions | 30 Comments

EGR, standing for Embryo/Gestation/Rearing, is the name of a mission presented by John Hunt on Tibor Pacher's PI Club site, where Tibor encourages the development of what he calls 'crazy ideas.' Crazy, that is, in terms of brainstorming, getting concepts out there for comment and growth. Hunt's is likely to be controversial on several levels, although its goal -- an insurance policy for the species -- is one this site can endorse. Why an insurance policy? As we've discussed recently, the number of existential threats facing our species makes the Fermi question pointed. Self-destruction would be an ignominious end for any culture, but one not inconsistent with factors as diverse as incoming asteroids, nuclear war or biological weaponry run amok. Hunt prefers to focus on a specific threat: Advances in the area of biotech, nanotech, and artificial intelligence are accelerating. Molecular manufacturing will also bring us the ability to produce chemicals which are entirely novel and...

Wired Looks at Advanced Propulsion

by Paul Gilster | May 5, 2009 | Breakthrough Propulsion | 26 Comments

Wired has picked up on our Frontiers of Propulsion Science book with just published interviews of Marc Millis and Eric Davis, co-editors of the volume. Interviewer Sharon Weinberger had a tough assignment, dealing with a 739 page collection of technical and scientific papers aimed, as she notes, at scientists and university students. But her questions were well chosen, particularly in drawing out why a book like this was necessary. Defining the Terms Marc Millis, founder of the Tau Zero Foundation, noted the need for a single, defining reference point outlining the current status of research and the opportunities presented. Thus the motivation: To clear the way for progress, my colleagues and I decided to compile this one document covering the status, issues, and unresolved questions behind a variety of known concepts, and to link the ideal goals back to real physics details. To the extent possible, we endeavored to treat these subjects impartially; showing both their visionary...

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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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