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Pluto/Charon: Surface Features Emerging

by Paul Gilster | Apr 30, 2015 | Outer Solar System | 17 Comments

One of the more memorable moments from yesterday's teleconference on the New Horizons mission was Alan Stern's comment that the latest pixelated images of Pluto/Charon constituted his 'meet Pluto moment.' If anyone has an interest in meeting Pluto, it's Stern (Southwest Research Institute), who serves as principal investigator and whose unflagging efforts made it possible. As for those pixelated views, well, they're a glimpse of what is to come, but even now, they're telling us helpful things about the target. The animation below speaks volumes, with the first showing Charon's rotation with the center of Pluto fixed in the frame. The images were acquired with the Long Range Reconnaissance Imager (LORRI) camera. Image: A series of LORRI images of Pluto and Charon taken at 13 different times spanning 6.5 days, from April 12 to April 18, 2015. During that time, the spacecraft's distance from Pluto decreased from about 111 million kilometers to 104 million kilometers. Pluto and Charon...

HD 7924: Planets with a Robotic Assist

by Paul Gilster | Apr 29, 2015 | Exoplanetary Science | 5 Comments

We've found a lot of planets far away from the Sun but know comparatively little about what may be circling nearby stars. The rationale is clear: The Kepler mission's field of view was carefully chosen to provide a large sample (over 145,000 main sequence stars) that could be studied for transits by the spacecraft's photometer. Looking out along the Cygnus arm of the Milky Way, far enough from the ecliptic plane to avoid the Sun, the Kepler stars have been providing statistical data to help us understand how common planets actually are in the galaxy. But as we saw with the announcement of a candidate planet around Alpha Centauri B, the news of planets closer to home excites interest. These are places close enough to us that they could conceivably be the targets of future interstellar probes. As we continue to look at the Kepler inflow, we're also anticipating missions like TESS (Transiting Exoplanet Survey Satellite), scheduled for a 2017 launch, and PLATO (PLAnetary Transits and...

DSAC: Paradigm Changer for Deep Space Navigation?

by Paul Gilster | Apr 28, 2015 | Communications and Navigation | 7 Comments

We need to improve the way we handle data tracking and deep space navigation. While the near term is always uncertain because of budgetary issues, we can still take the long view and hope that we're going to see a steadily increasing number of robotic and human spacecraft in the Solar System. That puts a strain on our existing facilities, and a premium on any methods we can find to make data return more precise and navigation more autonomous. With these ideas in mind, keep your eye on the Deep Space Atomic Clock (DSAC). It's a NASA technology demonstrator mission being built to validate a miniaturized, ultra-high precision mercury-ion atomic clock that researchers believe will be 100 times more stable than today's best navigation clocks. Managed at the Jet Propulsion Laboratory, the DSAC has been tweaked and improved to the point where it allows drift of no more than a single nanosecond in ten days. Image: Drawing of the DSAC mercury-ion trap showing the traps and the titanium vacuum...

Exoplanet Spectrum in Visible Light

by Paul Gilster | Apr 27, 2015 | Exoplanetary Science | 2 Comments

It's the twentieth anniversary of the discovery of 51 Pegasi b, a 'hot Jupiter' that was the first planet to be discovered around a normal star. I always have to throw in that 'normal' qualifier because it was in 1992 that Aleksander Wolszczan and Dale Frail announced their discovery of planets around the pulsar PSR 1257+12, the first extrasolar planets ever found, and an extraordinary discovery in themselves. Michel Mayor and Didier Queloz announced the 51 Pegasi b discovery in 1995, and it was quickly confirmed by Geoff Marcy and Paul Butler. 51 Pegasi b, some 50 light years from Earth in the constellation Pegasus, is the prototypical 'hot Jupiter,' a gas giant orbiting in tight proximity to its star. A new paper from Jorge Martins (Universidade do Porto, Portugal) and team announces another first for this world, the first detection of the spectrum of visible light reflected off an exoplanet. The detection was made by painstakingly removing the host star's spectrum to reveal the...

Habitable Worlds Around Tau Ceti?

by Paul Gilster | Apr 24, 2015 | Exoplanetary Science | 25 Comments

Yesterday's look at NExSS (the Nexus for Exoplanet System Science), NASA's new 'virtual institute,' focused on the multidisciplinary nature of the effort. The work I'm looking at today, an analysis of the planets around Tau Ceti performed at Arizona State University, only emphasizes the same point. To get a read on whether two planets that are possibly in Tau Ceti's habitable zone are likely to be terrestrial worlds like Earth, the ASU team brought the tools of Earth science into play, in particular the work of Sang-heon Shim. Shim is a mineral physicist who worked with astrophysicists Michael Pagano, Patrick Young and Amanda Truitt in the Tau Ceti analysis. His perspective was vital because early work had already suggested that Tau Ceti has an unusual balance between the rock-forming minerals magnesium and silicon. In fact, the ratio of magnesium to silicon here is 1.78, about 70% more than we find in the Sun. That casts long-standing views of Tau Ceti as Sol's twin into doubt, and...

NExSS: A ‘Virtual Institute’ for Deep Space

by Paul Gilster | Apr 23, 2015 | Culture and Society | 4 Comments

The Nexus for Exoplanet System Science, or NExSS, is a collaborative initiative from NASA to draw on the collective talent of researchers from ten universities, three NASA centers and two research institutes. Conceived as a 'virtual institute,' the effort is both geographically diverse and multidisciplinary in nature, focusing not only on the search for exoplanets but the attempt to analyze planetary environments and find life. Jim Green, NASA's Director of Planetary Science, explains the concept: "This interdisciplinary endeavor connects top research teams and provides a synthesized approach in the search for planets with the greatest potential for signs of life. The hunt for exoplanets is not only a priority for astronomers, it's of keen interest to planetary and climate scientists as well." NExSS draws on the collective expertise of its participants in the areas of Earth science, planetary science within our Solar System, heliophysics and astrophysics to create what NASA is...

Project Dragonfly: Design Competitions and Crowdfunding

by Paul Gilster | Apr 22, 2015 | Sail Concepts | 49 Comments

by Andreas Hein Centauri Dreams readers most likely know Andreas Hein as the head of Project Hyperion, an effort for Icarus Interstellar to examine the prospects for manned interstellar flight, but he has also written in these pages about the uploading of consciousness. Now working on his PhD at the Technical University of Munich, Andreas today tells us about a new Kickstarter campaign in support of Project Dragonfly. Developing under the auspices of the Initiative for Interstellar Studies (of which Andreas is deputy director), Dragonfly explores interstellar flight at the small scale, and as he explains below, leverages the advances in computing and miniaturization that designers can use to change the paradigm of deep space missions. Humanity has existed for over 200,000 years. It is only about 200 years since we entered the age of industrialization, and in the last 50 years, we have discovered ways of going to the stars [1]. However, the approaches conceived required spaceships the...

Voyager to a Star?

by Paul Gilster | Apr 21, 2015 | Culture and Society | 38 Comments

The latest imagery from New Horizons has me wondering what it must be like to be on the team for this mission. Although released a week ago, the photo at left was taken by the Ralph color imager aboard the spacecraft on April 9. The distance from Pluto and Charon in the shot is about 115 million kilometers. This is the first color image ever made of Pluto/Charon by an approaching spacecraft, one that gives us a sense of what lies ahead as the distance continues to diminish. Imagine being part of this long effort and seeing a new world and its system of moons swimming into focus, unveiling landscapes never before seen. New Horizons takes me back to the Voyager days, and in the context of the approach to Pluto/Charon, the publication of Jim Bell's The Interstellar Age (Dutton, 2015) is truly apropos (I'm sure the publishers had exactly this in mind). Subtitled "Inside the Forty-Year Voyager Mission," the book lets us glimpse what it was like inside JPL when the planetary encounters...

Transient Listening: A Caution

by Paul Gilster | Apr 20, 2015 | Astrobiology and SETI | 9 Comments

by James Benford Searching for the faintest of signals in hopes of detecting an extraterrestrial civilization demands that we understand the local environment and potential sources of spurious signals. But we've also got to consider how signals might be transmitted, the burden falling on SETI researchers to make sense out of the physics (and economics) that constrain distant beacon builders. James Benford, CEO of Microwave Sciences and a frequent Centauri Dreams contributor, now looks at the problem in light of recent transients and discusses how we should move forward. The recent activity on Perytons leads us to a major lesson. We have a vast microwave network all around us that can interfere with transient radio astronomy. Our cell phones, though not powerful, influence the stronger transmitters and antennas of the cell phone towers. Add to that the many Internet hubs, microwave ovens, wireless equipment and extensive communication webs. All these may have fast transients with...

Exomoons: A Data Search for the Orbital Sampling Effect and the Scatter Peak

by Paul Gilster | Apr 17, 2015 | Exoplanetary Science | 11 Comments

Exomoons continue to be elude us, though they're under intense study. One detection strategy is called Orbital Sampling Effect, as explained in the article below. I'll let Michael Hippke describe it, but the intriguing fact is that we can work with these methods using existing datasets to refine our techniques and actively hunt for candidates. Michael is a researcher based in Düsseldorf, Germany. With a background in econometrics, statistics and IT, he mastered data analysis at McKinsey & Company, a multinational management consulting firm. These days he puts his expertise to work in various areas of astrophysics, and most recently appeared here in our discussion of his paper on Fast Radio Bursts (see Fast Radio Bursts: SETI Implications?). by Michael Hippke Our own Solar System hosts 8 planets (plus Pluto and other "dwarf planets"), but 16 large moons with radii over 1,000km. And we have detected thousands of exoplanets - planets orbiting other stars - but not a single exomoon. The...

G-HAT: Searching For Kardashev Type III

by Paul Gilster | Apr 16, 2015 | Astrobiology and SETI | 30 Comments

A new paper out of the Glimpsing Heat from Alien Technologies search (G-HAT) at Penn State is packed with fascinating reading, and I’m delighted to send you in its direction (citation below) for a further dose of the energizing concepts of ‘Dysonian SETI.’ Supported by a New Frontiers in Astronomy and Cosmology grant funded by the John Templeton Foundation, G-HAT has been studying whether highly advanced civilizations are detectable through their waste heat at mid-infrared wavelengths, a tell-tale signature posited by Freeman Dyson in the 1960s. We now have the highly useful dataset of some 100 million entries gathered by WISE, the Wide-field Infrared Survey Explorer mission, to work with. G-HAT researcher Roger Griffith, lead author of the paper on this work, went through these data, culling out 100,000 galaxies that could be seen with sufficient detail, and searching for any that produced an unusually strong mid-infrared signature. Fifty galaxies do show higher levels of...

Perytons: A Microwave Solution

by Paul Gilster | Apr 15, 2015 | Deep Sky Astronomy & Telescopes | 6 Comments

Radio bursts scant milliseconds long that have been reported at the Parkes radio telescope in New South Wales -- so-called ‘perytons’ -- turn out to be the product of microwave ovens. The Case of the Puzzling Perytons, as Earl Stanley Gardner might have titled it, appeared in these pages earlier, with alliteration intact, when Jim Benford tackled it in Puzzling Out the Perytons. You’ll recall that Benford thought microwave ovens were involved, and now we learn that the Parkes team had independently reached the same conclusion before he arrived. Moreover, the authors of the Parkes paper had already embarked upon an investigation that now yields positive results. Make no mistake, this is a useful finding, even if it has generated a certain degree of understandable banter. After all, we’re looking for emissions from deep space but fending off spurious signals generated by staff lunching on the grounds of the observatory itself. The larger picture, though, is that the kind of signals our...

New Horizons Message Update

by Paul Gilster | Apr 14, 2015 | Astrobiology and SETI | 14 Comments

If you want to send a message to the stars, Jon Lomberg is the man to consult. A gifted artist and creator of the gorgeous Galaxy Garden in Kona, Hawaii, Lomberg may be most famous for his frequent work with Carl Sagan, including the celebrated Cosmos series. But it’s his involvement with the Voyager Interstellar Record, a project for which he served as design director, that makes him so uniquely qualified to embark on a new messaging effort, the One Earth: New Horizons Message project. Let’s talk about Voyager and how the new message differs. 115 images and 27 musical selections went into the Voyager record, along with abundant audio of the life and natural sounds of our planet. The 12-inch gold-plated copper disk included spoken greetings in fifty-five languages beginning with Akkadian (a language of ancient Sumer) and ending with Wu, a modern Chinese dialect. The ninety minutes of music can be played at 16 ? revolutions per minute using a cartridge and needle enclosed within the...

Call for Participation: TVIW 2016

by Paul Gilster | Apr 13, 2015 | Culture and Society | 1 Comment

I like the theme of the just announced 2016 iteration of the Tennessee Valley Interstellar Workshop. Set in Chattanooga, TN, the meeting will convene at a local landmark, the Chattanooga Choo-Choo Hotel, which is actually built around the old railroad station made famous in the Glenn Miller tune of the same name. What better way to describe the upcoming event than what the group has chosen: "From Iron Horse to Worldship: Becoming an Interstellar Civilization." The Chattanooga event follows two previous meetings in Oak Ridge and one in Huntsville, AL, all of which I've had the pleasure of attending. The level of engagement I've found at TVIW has made all the meetings a success, beginning with the first, in Oak Ridge, back in 2011. That one sticks in my mind because of the intense fog that hung over the mountains as I drove in the evening before. The discussions and presentations were stimulating throughout, with an emphasis on more engagement with audience members than in a formal...

Near-Term Missions: What the Future Holds

by Paul Gilster | Apr 10, 2015 | Exoplanetary Science | 28 Comments

Discussing the state of space mission planning recently with Centauri Dreams contributor Ashley Baldwin, I mentioned my concerns about follow-up missions to the outer planets once New Horizons has done its job at Pluto/Charon. No one is as plugged into mission concepts as Dr. Baldwin, and as he discussed what's coming up both in exoplanet research as well as future planetary missions, I realized we needed to pull it all together in a single place. What follows is Ashley's look at what's coming down the road in exoplanetary research as well as planetary investigation in our own Solar System, an overview I hope you'll find as useful as I have. Dr. Baldwin is a consultant psychiatrist at the 5 Boroughs Partnership NHS Trust (Warrington, UK) and a former lecturer at Liverpool and Manchester Universities. He is also, as his latest essay makes clear, a man with a passion for what we can do in space. by Ashley Baldwin We've come a long way since the discovery of the first "conventional"...

Enter ‘Galactic Archaeology’

by Paul Gilster | Apr 9, 2015 | Deep Sky Astronomy & Telescopes | 15 Comments

I've used the term 'interstellar archaeology' enough for readers to know that I'm talking about new forms of SETI that look for technological civilizations through their artifacts, as perhaps discoverable in astronomical data. But there is another kind of star-based archaeology that is specifically invoked by the scientists behind GALAH, as becomes visible when you unpack the acronym -- Galactic Archaeology with HERMES. A new $13 million instrument on the Anglo-Australian Telescope at Siding Spring Observatory, HERMES is a high resolution spectrograph that is about to be put to work. Image: I can't resist running this beautiful 1899 photograph of M31, then known as the Great Andromeda Nebula, when talking about our evolving conception of how galaxies form. Credit: Isaac Roberts (d. 1904), A Selection of Photographs of Stars, Star-clusters and Nebulae, Volume II, The Universal Press, London, 1899. Via Wikimedia Commons. And what an instrument HERMES is, capable of providing spectra in...

Ganymede Bulge: Evidence for Its Ocean?

by Paul Gilster | Apr 8, 2015 | Outer Solar System | 1 Comment

What to make of the latest news about Ganymede, which seems to have a bulge of considerable size on its equator? William McKinnon (Washington University, St. Louis) and Paul Schenk (Lunar and Planetary Institute) have been examining old images of the Jovian moon taken by the Voyager spacecraft back in the 1970s, along with later imagery from the Galileo mission, in the process of global mapping. The duo discovered the striking feature that Schenk described on March 20 at the 46th Lunar and Planetary Science Conference in Texas. Says McKinnon: "We were basically very surprised. It's like looking at old art or an old sculpture. We looked at old images of Ganymede taken by the Voyager spacecraft in the 1970s that had been completely overlooked, an enormous ice plateau, hundreds of miles across and a couple miles high… It's like somebody came to you and said, 'I have found a thousand mile wide plateau in Australia that was six miles high.' You'd probably think they were out of...

In Search of Colliding Stars

by Paul Gilster | Apr 7, 2015 | Deep Sky Astronomy & Telescopes | 8 Comments

How often do two stars collide? When you think about the odds here, the likelihood of stellar collisions seems remote. You can visualize the distance between the stars in our galaxy using a method that Rich Terrile came up with at the Jet Propulsion Laboratory. The average box of salt that you might buy at the grocery store holds on the order of five million grains of salt. Two hundred boxes of salt, then, make a billion grains, while 20,000 boxes give us 100 billion. That’s now considered a low estimate of the number of stars in our galaxy, which these days tends to be cited at about 200 billion, but let’s go with the low figure because it’s still mind-boggling. So figure you have 20,000 boxes of salt and you spread the grains out to mimic the actual separation of stars in the part of the galaxy we live in. Each grain of salt would have to be eleven kilometers away from any of its neighbors. These are considerable distances, to say the least, but of course there are places in the...

Puzzling Out the Perytons

by Paul Gilster | Apr 6, 2015 | Astrobiology and SETI | 26 Comments

Recently we looked at Fast Radio Bursts (FRBs) and the ongoing effort to identify their source (see Fast Radio Bursts: SETI Implications?) Publication of that piece brought a call from my friend James Benford, a plasma physicist who is CEO of Microwave Sciences. Jim noticed that the article also talked about a different kind of signal dubbed 'perytons,' analyzed in a 2011 paper by Burke-Spolaor and colleagues. Detected at the Parkes radio telescope, as were all but one of the FRBs, perytons remain a mystery. As described in the essay below, Jim's recent trip to Australia gave him the opportunity to discuss the peryton question with key players in the radio astronomy community there. He has a theory about what causes these odd signals that is a bit closer to home than some of our speculations on the separate Fast Radio Burst question, and as he explains, we'll soon know one way or another if he's right. by James Benford A few weeks ago I visited Swinburne University in Melbourne...

Migratory Jupiter: A Theory of Gas Giant Formation

by Paul Gilster | Apr 3, 2015 | Outer Solar System | 17 Comments

An interesting model of planetary formation suggests that the architecture of our Solar System owes much to the effects of the giant planets as they migrated through the protoplanetary disk. Frédéric Masset (Universidad Nacional Autónoma de México) and colleagues go so far as to speculate that planetary embryos in orbits near Mars and the asteroid belt may have migrated outwards, depleting the region of materials that would become the cores of Jupiter and Saturn. The key is the heat an embryonic planet generates in the protoplanetary disk. Writing in Nature, the authors describe computations that model what happens to the rocky cores that will become gas giants. Tidal forces affecting planets in the protoplanetary disk have been thought to cause them to lose angular momentum, making their orbits gradually decay. The migration in this case should be inwards toward the star. But the researchers' model takes heat generated by material impacting onto the...

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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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