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  • Brain teasers from space

    NASA / JPL / SSI
    A natural-color image provided by the Cassini orbiter shows Saturn's southern
    hemisphere and the planet's main rings. Click on the image for a larger version.

    Did you know that Saturn's rings are wavy? Which Mars probe is back in business after it ran into trouble? How many rookies are on the space shuttle Endeavour? Which Apollo 11 crew member never set foot on the moon? Test your wits - and exercise your curiosity.

    We've freshened up three brain-teasing quizzes that just might boost your brain power as well. But first, let's consider some observations that are tickling the brains of the bright folks associated with the international Cassini mission to Saturn:

    Waves in Saturn's rings?
    Traditional views of Saturn, like the freshly released picture above, make the planet's rings look as flat as a phonographic record (remember those?). But other images from Cassini's cameras have revealed something that hasn't been seen so well before: vertical ring structures that are attributed to the gravitational effects of a 5-mile-wide (8-kilometer-wide) moon.

    The findings from Cassini's imaging team were published online this week in The Astronomical Journal, and addressed as well in a news release issued Thursday.

    Over most of their area, Saturn's main rings are only about 30 feet (10 meters) thick, but the ring particles (which are mostly water ice) can be perturbed along their edges by gravitational interactions with moons that circle in gaps within the rings. The latest imagery focuses on a tiny moon called Daphnis, which pushes the ring material into structures that tower as high as a mile (1.5 kilometers).

    When the rings are nearly edge-on to the sun, as they are right now, the structures cast long shadows that Cassini chronicled in the imagery shown below. Such imagery can be taken only every 15 years or so, when Saturn is near its equinox.

    NASA / JPL / SSI
    Never-before-seen looming vertical structures created by the tiny Saturnian moon
    Daphnis cast long shadows across the planet's rings in this startling image taken
    by the Cassini orbiter as Saturn approaches its mid-August equinox.

    "We thought that this vertical structure was pretty neat when we first saw it in our simulations," said John Weiss, the research paper's lead author. "But it's a million times cooler to have your theory supported by such gorgeous images.  It makes you suspect you might be doing something right."

    Weiss' co-authors are Carolyn Porco, head of the Cassini imaging team at the Colorado-based Space Science Institute, and Cornell astronomer Matthew Tiscareno. The research paper also delves into the theory behind gap-embedded moons. During observations yet to come, Cassini's team plans to look at other gaps in hopes of finding some missing moons.

    "It is one of those questions that have been nagging at us since getting into orbit: 'Why haven't we yet seen a moon in every gap?'" Porco said in the news release. "We now think they may actually be there, only a lot smaller than we expected."

    Triple dose of trivia
    Here's your very own opportunity to tackle some nagging scientific questions:

    • Test your Sci-Q: We've updated the Science/Space news quiz with a fresh batch of brain teasers, based on the week's news.
    • How's your shuttle IQ? Our space shuttle quiz has also been freshened up with a few questions about Endeavour's mission to the international space station, due for launch early Saturday.
    • Apollo trivia revisited: The 40th anniversary of the Apollo 11 moon landing coming up next month, and in the weeks to come you'll be hearing a lot more about NASA's glorious past and uncertain future. Test your Apollo IQ, and if you need to refresh your memory, we have just the reading list for you.

    Join the Cosmic Log corps by signing up as my Facebook friend or hooking up on Twitter. And if you really want to be friendly, ask me about my upcoming book, "The Case for Pluto." 

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  • Hey, E.T.! The line is open

    SETI Institute
    Radio dishes monitor the skies over California at the Allen Telescope Array.

    After years of preparation and testing, the SETI Institute has released the first results from a search for alien signals that uses the $50 million, 42-dish Allen Telescope Array. You didn't hear about it? Maybe that's because none of the thousands of signals picked up so far has rung an alarm bell.

    Nevertheless, the fully functioning system represents the latest, greatest leap in the nearly 50-year-long search for extraterrestrial intelligence, or SETI.

    The Allen Telescope Array was conceived more than eight years ago, and it's been two years since the system's switches were flipped on in a remote valley near Mount Shasta in Northern California. Scientists have been tinkering with the equipment and testing the software since then. Finally, on May 28, astronomers kicked off regular rounds of SETI surveys, seven hours a day, roughly four to five times a week, according to Peter Backus, the SETI Institute's manager of observing programs.

    Backus said the significance of the milestone sank in a couple of days later, when he and other members of the research team were sitting around a table for a planning meeting.

    "We just looked at each other and said, 'Hey, we're actually observing again!' It was a great feeling for the whole gang," he told me.

    Initial results from the SETI survey, as well as from seven other experiments conducted using the telescope array, were presented during poster sessions at this week's meeting of the American Astronomical Society in Pasadena, Calif.

    From big to little dishes
    Astronomers have been looking for alien radio signals since 1960, on the assumption that extraterrestrial civilizations would try communicating over light-years of empty space the way we might communicate with them. The trick is to identify signals that have the earmarks of an artificial source - but originate from deep space rather than from Earth or our own satellites.

    The SETI Institute's scientists have used several big radio dishes to do this work - including the Green Bank Telescope in West Virginia and the Arecibo Observatory in Puerto Rico. But they've had to wait in line along with other radio astronomers pursuing more, um, conventional research goals. At Arecibo, for example, the institute's Project Phoenix was allotted 2,400 hours of telescope time over the course of five and a half years.

    In 2001, the SETI Institute went ahead with plans to build a radio telescope of its own, in league with the University of California at Berkeley. Private benefactors, led by software billionaire Paul Allen, kicked in millions of dollars to get the ball rolling.

    Unlike Arecibo, the Allen Telescope Array is composed of 42 separate dishes, each one 20 feet (6.1 meters) wide, which are networked together with software to create an observatory with the sensitivity of a single 133-foot-wide (40-meter-wide) dish. Eventually, astronomers hope to expand the array to 350 dishes.

    The array can be configured to target multiple spots on the sky simultaneously, or take readings for different experiments at the same time. For example, while the SETI Institute team looked for alien transmissions from the central region of our galaxy, Berkeley astronomers could check the same area for naturally occurring transient radio sources.

    Here's how the SETI watch works:

    • The telescope is aimed at two separate target spots for 98 seconds at a time. The software looks for pulsed, continuous signals that stand out from the static of space, as I explain in this archived audio clip. Such signals are checked against a database of previously detected, human-created radio transmissions. The signals that aren't in the database go on to the next round.
    • If the exact same signal is detected at both target locations, that's a sign of terrestrial interference. Sorry, no E.T.
    • If the signal emanates from only one of the targets, then the telescope shifts its beam slightly off-target. If the signal is still detected, it's not from a faraway source. Again, no E.T.
    • If the signal passes this first on-off test, the cycle is repeated a second time to see if the pattern persists. If the signal looks promising, then it's time to tell other astronomers to take a look and offer a second (or third, or fourth ...) opinion.

    On one night last week - June 3, to be exact - the system picked up a total of 8,616 signals to check. More than 90 percent of those were eliminated right away because they were matched up with the database of previously known signals. Just 180 of the remaining signals hung around long enough for further checking. The "same signal from two places" test eliminated all but two of those signals. The first on-off test eliminated one of those two, and the second on-off test eliminated the other one.

    Bottom line: a big fat zero.

    Searching while humans sleep
    Watching all this happen might be an exercise in disappointment. So maybe it's a good thing that all this takes place automatically, without a human tracking the hopes as they're dashed nightly.

    "The 'carbon-based units' are blissfully asleep," Backus said. "At 8 o'clock in the morning, we get an e-mail."

    Another plus is that the researchers don't have to sleep on cots at the telescope site. The SETI search, like most astronomy projects nowadays, can be monitored remotely.

    "A couple of weeks ago I was doing some engineering tasks in the predawn hours - in my pajamas, at my home computer," Backus recalled.

    In any SETI quest, so many earthly signals are picked up that astronomers have gotten used to the routine of eliminating the possibilities until nothing is left. "When we have a system that is sensitive to [radio] sources that are light-years away, it's easy to pick up something from just down the street," Backus said.

    The nice thing is that astronomers now have the power to tinker and tweak their own telescope to optimize the search. Eventually, they'll be doing SETI seven days a week, 24 hours a day. "We're happy to refine the procedure as we learn," Backus said.

    And one of these days, those astronomers just might get a computerized e-mail that doesn't have a big fat zero on the bottom line. Then what?

    Feel free to chime in with your comments below, and click the links to read bygone tales from the SETI quest:

    ... And here's a roundup of the Cosmic Log items from this week's AAS meeting:

    Join the Cosmic Log corps by signing up as my Facebook friend or hooking up on Twitter. And if you really want to be friendly, ask me about "The Case for Pluto." 

  • Grand galactic views

    S.V. Ramirez / NExSci / Caltech / JPL / NASA
    This infrared image from NASA's Spitzer Space Telescope shows the center of the
    Milky Way galaxy, with three baby stars highlighted in the inset images.

    NASA's Spitzer Space Telescope has turned up infrared evidence of baby stars being born near the supermassive black hole at the center of the Milky Way. The discovery demonstrates that our home galaxy's most crowded neighborhood is more diverse than astronomers may have thought.

    "These stars are like needles in a haystack," Solange Ramirez, principal investigator of the research program at NASA's Exoplanet Science Institute at the California Institute of Technology, said in a news release issued Wednesday. "There's no way to find them using optical light, because dust gets in the way. We needed Spitzer's infrared instruments to cut through the dust and narrow in on the objects."

    In its current condition, the Milky Way's center isn't the kind of place you'd think infant stars would find much footing. Until now, astronomers haven't had much luck finding young stellar objects. But the Spitzer science team focused in on about 100 candidates and identified three stars that were less than a million years old, based on their spectral signatures in infrared wavelengths.

    "It is amazing to me that we have found these stars," Ramirez said. "The galactic center is a very interesting place. It has young stars, old stars, black holes, everything. We started mining a catalog of about 1 million sources and managed to find three young stars - stars that will help reveal the secrets at the core of the Milky Way."

    And not just the Milky Way, according to Deokkeun An of Caltech's Infrared Processing and Analysis Center, who is the lead author of a research paper submitted to The Astrophysical Journal. "By studying individual stars in the galactic center, we can better understand how stars are formed in different interstellar environments," An said in Wednesday's news release.

    The Spitzer imagery was unveiled during this week's meeting of the American Astronomical Society in Pasadena, Calif. Here are other tales of galactic goings-on from the AAS agenda:

  • Planet debate shifts focus

    SwRI
    A map of Pluto's surface,
    based on brightness.

    The main players in the planethood debate gathered together this week to look back at Pluto's woes - and look ahead to fresh discoveries on the solar system's farthest frontiers.

    Among the speakers at Tuesday's forum, held at the American Astronomical Society's summer meeting in Pasadena, Calif., were Neil deGrasse Tyson, the astrophysicist and planetarium director whose Pluto-less planetary display contributed to the controversy, and Alan Stern, the planetary scientist who heads NASA's New Horizon science mission to Pluto and its neighbors on the solar system's edge.

    In all, seven speakers revisited the International Astronomical Union's decision three years ago to issue a definition of planethood that excluded Pluto because it hadn't "cleared its orbit" of other objects close to its size.

    Pluto and other round objects beyond Neptune were instead classified as "dwarf planets," and later as "plutoids" - sparking protests from Pluto's planetary defenders.

    It's safe to say that no one's mind was changed up on the speakers' platform: Tyson traced Pluto's troubled past - including a progressive downsizing of size estimates that led astronomers to joke during the 1970s that the planet would disappear completely by 1984. As it happened, more objects like Pluto were found starting in 1992, climaxing with the 2005 discovery of another ice world that is bigger than Pluto. (The uncertain status of the newfound object, now known as a dwarf planet named Eris, is what sparked the IAU's decision a year later).

    Moving on?
    In Tyson's view, it's time to move on. He noted that the solar system contained a wide diversity of objects that could be sliced and diced into categories ranging from shape and composition to geology and suitability for life.

    "This is what we should be thinking about now, not arguing over the fricking definition of a planet," Tyson wisecracked.

    Stern agreed that the solar system's diversity should be the focus of the debate. But he said the way we think of planets should reflect that diversity. The way he sees the issue, objects like Pluto make up the most numerous class of planets in the solar system - and objects like Earth should be considered the true oddballs. "I think there's a bit of a Copernican revolution," Stern observed.

    Other speakers added their own particular perspectives:

    • Charles Beichman, executive director of NASA's Exoplanet Science Institute, noted the difficulties in using any single criterion for defining planets. The IAU backed off from setting up a standard for extrasolar planets three years ago, and Beichman joked that the standard once cited by a Supreme Court justice for obscenity might have to be used: "I know it when I see it."
    • The University of Arizona's Renu Malhotra noted that Pluto ended up sparking a revolution in the way scientists thought about planets. Today, Malhotra and other astronomers say Pluto and its kin were pushed outward in a grand migration of the solar system's outer planets. "The planets did not form where we find them today," she said.
    • Mark Sykes, director of the Planetary Science Institute, argued that a broad definition for planets - that is, a definition that accepts anything that is massive enough to crush itself into a round shape due to self-gravity - should win out because it's easier to understand and leads to more logical groupings of celestial objects. He sketched out a Venn diagram categorizing objects that had geological processes, atmospheres and the potential for life. "It makes sense to group all these things together as planets," he said.
    • Jean-Luc Margot, an astronomer at the University of California at Los Angeles, took a fresh approach to the whole definition question: Stick to the IAU's view on planethood, and set aside the word "world" to apply to round objects like Pluto as well as satellites like Saturn's Titan and Earth's moon. The world definition also would apply to free-floating objects that don't orbit any star. "Some worlds are planets, others are not," he said.
    • Vanderbilt University's David Weintraub traced the twists and turns in the concept of planethood over three centuries, noting that scientists often got it wrong. (For example, by thinking that planets had to follow a distance pattern known as the Titius-Bode rule.) Weintraub - author of the book "Is Pluto a Planet?" - said he'd like to see a sensible definition of the word "but I'm not sure we're anywhere close to being able to do that."

    Tuesday's forum was remarkably free of rancor. In fact, the loudest exchange came between Tyson and Bill Nye (the Science Guy), who was sitting in the second row of the hall and went on a mock rant over the term "trans-Neptunian object," which scientists use to refer to solar system objects even if they don't cross Neptune's orbit.

    "'This is not complicated," Nye said "'Trans' means across, 'ultra' means beyond!"

    The question on many people's minds was whether there would be an effort to modify or overturn the IAU's definition at the organization's next meeting, set for August in Rio de Janeiro. Based on the views aired on Tuesday, neither side sounds anxious to have IAU officials revisit the issue in Rio.

    "I think they should quit while they're behind," Stern said.

    The last word
    If the IAU's deliberations are being left behind, what's ahead? Caltech astronomer Mike Brown, whose discovery of Eris kicked the whole debate into high gear, said today during a different AAS session that he tries to avoid talking about whether or not Pluto should be a planet. (After the 2006 decision, he declared himself satisfied with the outcome.)

    Now Brown is focusing on Pluto's kin at the solar system's edge - fellow dwarf planets such as the fast-spinning, football-shaped world named Haumea, and a mysterious far-flung object called Sedna.

    Sedna inhabits what appears to be something of a no-man's land between the solar system's Kuiper Belt and the cometary Oort Cloud. However, statistical analyses suggest that there should be about 40 objects out there that are at least as big as Sedna. Some of those objects may even be big enough to reignite the "What is a Planet" debate yet again.

    After his talk, Brown told me he's looking forward to the Hubble Space Telescope's return to service this summer, because he has several observational opportunities coming up that could shed more light on the solar system's farthest, dimmest frontier. He gave Hubble a high rating on the telescope scale. "It's the coolest one out there," he said.

    I've written a whole book about this planethood issue, titled "The Case for Pluto," It should be out in November. I mention this only because I feel as if I'm short-changing you when it comes to the whole discussion that took place this week. To make partial amends, I've put together a bare-bones Web page that combines all of my Twitter updates from the planet forums (and the updates I would have made if I hadn't violated Twitter's tweet-per-hour limit).

    You can watch some of Tuesday night's action via Ustream's video archive.

    Join the Cosmic Log corps by signing up as my Facebook friend or hooking up on Twitter. If you really want to be friendly, give some thought to "The Case for Pluto." 

  • Citizen astronomers unite

    STScI
    Astronomer Galileo Galilei made these drawings of the moon based on telescope
    observations made four centuries ago. Could you do any better? The Galileoscope
    project is planning a contest for sketchers and photographers.

    The International Year of Astronomy isn't just for astronomers anymore: There's a whole constellation of projects aimed at getting regular folks like you and me involved in celestial adventures.

    "Anyone can be a space explorer, just by going outside at night and looking up with a little bit of a prepared mind," said Andrew Chaikin, a former editor of Sky & Telescope magazine who wrote "A Man on the Moon," the classic history of the Apollo moon effort.

    Chaikin did a little bit of virtual exploration himself, after coming upon 40-year-old Apollo 11 imagery that revealed a little-seen side of moonwalker Neil Armstrong. You can get the details from this updated item about Apollo history, or from CollectSpace's video-enhanced report.

    Do-it-yourself space science extends far beyond archival searches. Some of the leaders of the citizen astronomy movement provided status reports on their own missions at this week's American Astronomical Society meeting in Pasadena, Calif. Here's just a sampling:

    Galileoscope: Shipments of a high-tech, low-cost telescope, modeled after the instrument used by Galileo Galilei 400 years ago, are making their way from China to the United States and other destinations by boat. About 60,000 telescope kits have been sold in advance, at a retail price of $15 (less for bulk quantities). Buyers should be receiving the kits by the end of July. The next steps include figuring out how many more telescopes should be made before the production line is shut down (get your orders in now!) ... and also setting up a contest for Galileoscope imagery. The idea is to solicit photos of celestial objects taken through the telescope, as well as drawings based on Galileoscope observations (a la Galileo, as shown above). Contest rules and submission procedures will be on the Galileoscope Web site when they're ready for release. The first round of winners should be announced by the end of the year.

    Galaxy Zoo: The Galaxy Zoo 2 project has recruited more than 200,000 participants to sort through online pictures of galaxies from the Sloan Digital Sky Survey and classify them according to their shape - something that human eyes and brains can do much more easily than computers. During the "100 Hours of Astronomy" celebration in April, more than 2.5 million classifications were made - and if you count up all the clicks since Galaxy Zoo 2 started in February, the classifications add up to 32 million. Combine that with Galaxy Zoo 1's results, and you get more than 100 million galaxy checkups. The Galaxy Zoo team says that's the equivalent of a Ph.D. student working for almost 20 years without sleep or a coffee break. The project already has spawned a dozen journal articles - relating to patterns in galaxy rotation, for example, or the effects of galaxy mergers.

    Star parties galore: If you thought "100 Hours of Astronomy" was big, just you wait: IYA organizers are planning a collaboration with the Year of Science celebration starting in July, a worldwide moon-watching effort on Aug. 1 (linked to NASA's LCROSS moon-smashing mission), a "Galilean Nights" festival on Oct. 23-24 (featuring Jupiter and its moons). They'll take on a big role in this year's Great World Wide Star Count in October as well. October also happens to be prime time for the year's second round of Astronomy Day celebrations.

    Social astronomy: Space fans are really catching on to social-networking tools such as Facebook and Twitter. You can follow updates from Endeavour shuttle commander Mark Polansky, for example, or from the Lunar Reconnaissance Orbiter that's slated for launch next week. (Today the plucky probe touts its "new movie trailer.") One idea that's circulating is to create a social network dubbed AstroTwitter to allow telescope handlers around the world to answer the question "What are you observing?" Another idea is to use Twitter as a way for observers to share their skywatching experiences online in real time, as British moon-watchers did during an experimental session last month. Don't forget to check in on the IYA's Facebook page and Twitter updates. I'm tweeting as well from the AAS meeting.

    Online astronomy: I've already written a fair amount about online astronomy programs such as the outward-looking side of Google Earth and Microsoft's World Wide Telescope. (Microsoft is a partner in the msnbc.com joint venture.) Watch for further updates and grassroots enhancements in the future, including a fresh beta release for the WWT next month. The Harvard-Smithsonian Center for Astrophysics' MicroObservatory is also coming into play, along with other portals to remote-controlled telescopes.

    Virtual-world astronomy: The virtual world known as Second Life boasts its own universe of astronomical projects. The online offerings have pushed light-years ahead in the two years since I first wrote about the virtual final frontier. To see how far things have gone, check out Second Astronomy and the Meta Institute for Computational Astrophysics.

    Stay tuned for further reports this week from the American Astronomical Society's summer meeting in Pasadena. Join the Cosmic Log corps by signing up as my Facebook friend or hooking up on Twitter. And if you really want to be friendly, ask me about my upcoming book, "The Case for Pluto." 

  • Measuring the universe

    Kochanek, Stanek, Prieto / Ohio State U.
    The galaxy M81, seen here in an image from the Large Binocular
    Telescope, is home to several ultra-long-period Cepheid variable stars that
    could help astronomers fine-tune a new way to measure cosmic distances.

    How far away is that galaxy? The more precise your answer is, the more you can find out about mysterious dark energy. In the past, astronomers have used variable stars and a special kind of supernova to make their distance estimates - and now two new measuring sticks are being added to the toolbox.

    One of the yardsticks is a particularly big and bright type of variable star, known as an ultra-long-period Cepheid variable, or ULP for short. The other yardstick makes measurements using the radio emissions from the supermassive black holes lying at the center of many galaxies, including our own.

    If the yardsticks can be fine-tuned in the years ahead, they can give scientists a better read on the universe's expansion rate over time, which is tied to a key number known as the Hubble constant. Right now, the number carries an uncertainty factor of 5 percent either way. If you want to get technical about it, the latest value is 74.2 kilometers per second per megaparsec, plus or minus 3.6, derived by the SHOES Team. That estimate is based on a combination of distance scales, with short-period Cepheid variables used for relatively close measurements and Type 1A supernovae for farther measurements.

    Cepheid variable stars are considered "standard candles" for measurement because their pattern of brightening and dimming correlates quite well with their intrinsic brightness. Thus, you can compare how bright the star looks with how bright the star really is, and come up with a pretty good distance estimate.

    Type 1A supernovae reveal a similar linkage between brightness and distance. But you need to use a closer-in measurement method, like the Cepheids, to calibrate the farther-out supernova measurements. That's a classic source of uncertainty: For example, if you say that 1 meter is equivalent to 3 feet, then multiply that figure to estimate how many feet equal a kilometer, your estimate would be off by about the length of a football field.

    A decade ago, the supernova measurements led astronomers to conclude that the universe's expansion rate was speeding up - apparently due to some repulsive energy in empty space, which has come to be known as dark energy. But what is dark energy? Is it a quality of the universe that varies over time, or has it been present throughout the universe's history? The Hubble Constant could hold the answer to that question, if we know the number accurately enough.

    Right now, the accuracy is just about good enough for a decision: The evidence so far suggests that dark energy has been ever-present, as a constant push on the cosmic expansion rate. The new yardsticks could help clinch the case - or push a big "reset" button on the theory-making machine.

    "There's going to be renewed interest in the Hubble Constant," because the uncertainty factor can be reduced with the new techniques, said Wendy Freedman, director of the Carnegie Observatories and one of the principal investigators for the Carnegie Supernova Project.

    Freedman said she and her colleagues hope to get the uncertainty factor down to 2 percent, using hundreds of hours of time on NASA's Spitzer Space Telescope to observe farther-out Cepheid variables in infrared wavelengths. But she said the brand-new yardsticks offer "promising techniques" to weed out distance conversion errors.

    The ultra-long perspective
    Ohio State University's Jonathan Bird, one of the researchers behind the ultra-long-period Cepheid yardstick, agreed. He compared the measurement schemes to different rungs on an extension ladder.

    "If we can extend all these rungs on the cosmic distance ladder, that's truly the way to beat down the systemic errors in the Hubble constant," he said Monday at a news conference during the American Astronomical Society's summer meeting in Pasadena, Calif.

    The ULPs are something like classical Cepheid stars, only with a much longer cycle of brightening and dimming. They're also brighter, which makes them easier than the classical Cepheids to spot at greater distances. At distances beyond 100 million light-years, most Cepheids are too dim to detect - but the ultra-long-period stars can still be seen at distances of 325 million light-years or so.

    The problem with the ULPs is that astronomers didn't think their periods correlated with their brightness, as is the case with the regular Cepheids. But Bird and his colleagues, led by Ohio State astronomer Krzysztof Stanek, pieced together data from previously published papers to come up with a system. Right now, the accuracy level is about 10 to 20 percent. With more observations, that accuracy should improve markedly, Bird said.

    Seeing the swirl around a black hole
    That's also the hope for the National Radio Astronomy Observatory's James Braatz and his colleagues with the Megamaser Cosmology Project. They are pioneering a method that relies on precise measurements of the linear and angular size of the disks of material that swirl around galactic black holes.

    Radio emissions from the disk could be analyzed to determine how fast one edge of a disk was moving away, and how fast the other edge was coming closer - providing the necessary numbers for calculating distance. Normally, those emissions would be too faint to pick up, but water molecules inside the disk itself amplified the signals. In effect, the water functioned like tiny molecular-scale lasers, or "masers."

    The maser technique was used to determine that a galaxy called UGC 3789 was 160 million light-years from Earth. Braatz told reporters that the observational feat was analogous to determining the size of a quarter sitting on his desk in Charlottesville, Va., as seen from the conference center in Pasadena, Calif.

    "We measured a direct, geometric distance to the galaxy, independent of the complications and assumptions inherent in other techniques," he said in Monday's news release. "The measurement highlights a valuable method that can be used to determine the local expansion rate of the universe, which is essential in our quest to find the nature of dark energy."

    The distance measurements for UGC 3789 were published in the April 10 issue of The Astrophysical Journal.

    For more on the dark-energy distance quest, check out these archived reports:

    Update/correction for 3:15 p.m. June 15: Astronomer Adam Riess, who was involved in the original observations of the cosmic speed-up as well as the latest observations relating to the Hubble constant, sent me an e-mail to correct the uncertainty factor I cited for the constant. I had a bit of conflicting information from Wendy Freedman and tried to reconcile what I was hearing with what I was reading, but Riess does a much better job of it. He's a professor at Johns Hopkins University as well as a researcher at the Baltimore-based Space Telescope Science Institute. Here's his e-mail:

    "There are a few small problems in your piece on 'Measuring the Universe.' The old Hubble constant measure from the HST Key Project (Freedman et al., 2001) had an uncertainty of 10%.  Our new one (which you quote without reference, its the SHOES Team, led by myself) has measured it to be 74.2 +/- 3.6.  You have the new numbers right but note that this is now a 5% uncertainty (3.6/74.2=0.05), not 10%,  which is now twice as good as the old one. Our measurement also already makes use of so-called ultra long period Cepheids.  I hope you can correct some of these. Good work otherwise as usual."

    I've made the corrections as suggested, and I've made sure to mention the SHOES team. Many thanks to Adam for setting all this straight, and thanks also to the commenters who wondered about the error percentages.  

    Correction for 2 a.m. ET June 9: I fixed a reference to light-year distances to add the word "million." That does make a difference. Sorry about the error, and thanks for setting me straight.

    Stay tuned for further reports this week from the American Astronomical Society's summer meeting in Pasadena. Join the Cosmic Log corps by signing up as my Facebook friend or hooking up on Twitter. And if you really want to be friendly, ask me about my upcoming book, "The Case for Pluto." 

  • Apollo in sharper focus

    NASA
    Astronaut Buzz Aldrin erects a solar wind experiment on the moon after Apollo 11's historic landing on July 20, 1969. Click on the image for a high-resolution view.

    That's one small step for a man ... and one giant stack of books for the 40th anniversary of the Apollo 11 moon landing.

    The pile of new publications about NASA's moon effort, timed to anticipate the anniversary on July 20, has been rising so high that Robert Pearlman, editor of the CollectSpace Web site, had to clear out his bookshelves this week. "I now have stacks of older books sitting around my office," he told me today.

    It's Pearlman's job to keep track of the memories and the memorabilia surrounding space missions, and even he is impressed by the breadth of offerings being released this year. "Each of them is slightly different - they're not just telling the same story over and over again," he said.

    That sentiment is echoed by Andrew Chaikin, author of "A Man on the Moon," the classic chronicle of the Apollo missions. "Apollo was such an enormous undertaking that I'm continually reminded that you can never truly know everything about that program. There were so many people, and so much, and all of them have their stories to tell," he said.

    'Amazing conversations' ... and amazing pictures
    Few writers have been better placed to tell those stories than Chaikin. In preparation for his 1994 book (which has since been updated), he conducted in-depth interviews with 23 of the 24 Apollo lunar astronauts. Much of that material just couldn't be used in "A Man on the Moon."

    "I had these amazing conversations with the astronauts, but I didn't let the astronauts speak directly to the reader except in the epilogue," Chaikin explained. "It wasn't that kind of book."

    This year, Chaikin wrote that kind of book - in league with his wife, Victoria Kohl. "Voices From the Moon" sets the choicest sound bites from the interviews alongside crisp images that illustrate the Apollo saga's main themes.

    Over the past couple of years, NASA has released fresh, high-resolution scans of the voluminous Apollo mission imagery, and Chaikin makes liberal use of those pictures to put the Apollo experience into sharper focus.

    "I did actually find some pictures that I had not seen before," he said. "One example is the picture that shows the moon in Earthlight with a bit of solar corona around it, that the Apollo 11 crew took. This is the moment at which Neil Armstrong tells Mission Control, 'It's a view worth the price of the trip.'"

    Some of the images revealed a little-seen side of Armstrong on the moon. In the course of researching "A Man on the Moon," Chaikin came across some 16mm film footage that was shot from the lunar lander as the astronauts worked on the surface. In some frames, Armstrong's face could be made out through his helmet visor.

    "That was something that always stayed with me - something that was very cool," Chaikin recalled in a CollectSpace video.

    When the pictures for "Voices From the Moon" were being selected, Chaikin knew that one of those frames just had to be included. He obtained digitized imagery from the film, and picked out the best screen grab for further enhancement. "I think it's fair to say that that is the best photograph of Neil Armstrong standing on the surface of the moon," he said.

    The astronauts' 'other' mission
    For decades, the lunar astronauts have been stereotyped as jet jocks who became tongue-tied when trying to describe what being on the moon was like. "They had no preparation whatsoever for the mission they never trained for - the mission that was handed to them by us when they came back from the moon, the mission that has been with them for the rest of their lives," Chaikin said.

    But Chaikin hopes that reading the astronauts' actual words will put that stereotype to rest. "What I conclude after talking with them at great length is that they did a superb job, an absolutely wonderful job," he said. "I would say 'Mission Accomplished,' to coin a phrase."

    "Voices From the Moon" serves as the perfect complement to "A Man on the Moon" - and I wouldn't be surprised if they end up being packaged as a two-book set. But there are plenty of other potential additions to your bookshelf. Whether you're a space fan or a comic fan, a youngster or an armchair historian, there's an Apollo book to suit your fancy.

    Here's a list of the latest and greatest hits, compiled with Pearlman's assistance:

    "Apollo: Through the Eyes of the Astronauts": NASA's Robert Jacobs, Michael Cabbage, Constance Moore and Bertram Ulrich edited this coffee-table book of classic Apollo photos, accompanied by synopses of each mission and quotes from the astronauts. While "Voices" is organized thematically (training through post-landing reflection), "Apollo" is organized chronologically (Apollo 7 through 17), which may make it easier for a space newbie to keep track of what happened when. There's also a foreword by physicist Stephen Hawking and his daughter Lucy Hawking.

    "Rocket Men: The Epic Story of the First Men on the Moon": Craig Nelson gives Apollo and the space effort the full nonfiction treatment in this 416-page history, due for release later this month. He draws upon interviews, NASA oral histories, declassified CIA documents and detail-rich reminiscences about the social milieu surrounding the moonshots. I love this single sentence describing what it was like around Cape Canaveral just before Apollo 11 was launched:

    "It was the middle of summer in the middle of Florida, meaning a heat that melted asphalt onto the soles of barefoot children and a humidity that made women sweat like Teamsters, especially that remarkable gaggle of lithe and adventurous females that made their way to Cocoa for every shot, pretty young things on the hunt for astronauts, or their best buddies, or somebody who worked at NASA, or somebody, girls who could be counted on to have a swinging time at the Satellite, Vanguard, Polaris, Rocket!, or Space Girls taverns, drinking liftoff martinis or moonlanders (vodka, soda, lime juice, creme de menthe, and creme de cacao)."

    "One Giant Leap: Apollo 11 Remembered": Space historian Piers Bizony's coffee-table book frames the Apollo 11 moon trip in the wider context of what came before (reaching back to Sputnik and earlier) and what came after (reaching ahead to Orion and NASA's future space vision).

    "Mission Control, This Is Apollo: The Story of the First Voyages to the Moon": Chaikin teams up with Apollo 12 astronaut Alan Bean to produce a book written for the 9- to 12-year-old set (or for older readers seeking a simple, straightforward account of the Apollo era). The photos, easy-to-understand graphics and Bean's space-themed paintings add to the book's appeal.

    "Painting Apollo: First Artist on Another World": Alan Bean's paintings take center stage in this coffee-table compilation of his artwork, accompanied by inspirational quotes. Essays from art experts and reminiscences from Apollo flight director Gene Kranz shed light on both sides of Bean's career - as a left-brain astronaut and a right-brain artist. The book, due for release next month, complements an upcoming exhibit of Bean's works at the Smithsonian's National Air and Space Museum.

    "Moon 3-D: The Lunar Surface Comes to Life": Cornell astronomer Jim Bell follows up on his book of 3-D stereo images from the Red Planet, "Mars 3-D," with this collection of lunar views. Most of the pictures were shot by Apollo astronauts carrying stereo cameras. A cleverly designed set of red-blue glasses is built right into the book cover, but I found it easier to use the cardboard 3-D glasses I always carry around in my pocket. (Doesn't everybody do that?) In the book's non-3-D section, Bell explains what the moon missions did for humanity and why we should push on with space exploration.

    "Missions to the Moon: The Complete Story of Man's Greatest Adventure": Writer/producer/director Rod Pyle's latest volume is a cross between a visual encyclopedia and a scrapbook. Each two-page chapter serves up a slice of space history, seasoned heavily with pictures. Most of the pages have pocket inserts that contain facsimiles of historical documents - for example, a page from the FBI's file on Wernher von Braun, or a copy of the Apollo 11 mission report, or a memo about the crew's flight insurance. Little kids would probably love to get their hands on this book, but parents may not let them.

    "Magnificent Desolation: The Long Journey Home From the Moon": Apollo 11 astronaut Buzz Aldrin's memoir, written with Ken Abraham and due for release this month, doesn't stop with splashdown: Aldrin recounts the steps leading up to the historic mission, the stumbles that came afterward due to depression and alcoholism, his path to redemption and the road ahead. Aldrin has also come out with his second children's book, "Look to the Stars" (illustrated by Wendell Minor).

    "Moonshot: The Flight of Apollo 11": Illustrator/author Brian Floca presents a beautiful children's book about humanity's first moon landing, suitable for ages 4 and older.

    "Hornet Plus Three: The Story of the Apollo 11 Recovery": Bob Fish, a retired Marine who is now a trustee for the USS Hornet Museum in California, tells the Apollo 11 saga from the viewpoint of the people who picked up the space crew in the Pacific.

    "Spacesuits": This coffee-table book doesn't focus so much on the men who flew to the moon, but rather on the clothes that kept them alive. Photographs document how the astronauts' spacesuits were made and how they look now in the Smithsonian's collection. There are even X-ray views that reveal what's inside. The text is by Amanda Young and the photos are by Mark Avino, both of whom are on the staff of the National Air and Space Museum.

    "T-Minus: The Race to the Moon": If you're a comic-book ... er, graphic-novel aficionado, you'll love this tale of the space race. The story, written by Jim Ottaviani and illustrated by Zander Cannon and Kevin Cannon, touches upon the challenges that engineers and mission managers faced as well as the better-known exploits of the astronauts. Come to think of it, even readers who are not into graphic novels just might get into this one.

    With each passing year, more books about the Apollo adventure are being published, but we shouldn't forget about the books that have come before - including "Apollo: The Race to the Moon," by Charles Murray and Catherine Bly Cox; and "Live From Cape Canaveral," by longtime NBC correspondent Jay Barbree.

    Virtually every Apollo astronaut has had a book written about him, if he hasn't written one himself. My guess is that "First Man" is the best-known biography (and the weightiest). For still more summer reading, check out Ken's Lunar Library at the "Out of the Cradle" Web site, plus CollectSpace's Publications & Multimedia forum.

    Over the decades, the memories of the Apollo generation have faded somewhat, Chaikin acknowledged. "It's the nature of human recollection," he said. "But the emotional content is among the most precious aspects of their testimony."

    Pearlman said the passage of time may be one reason why the 40th anniversary has become such a big deal.

    "We're losing some of the tangible histories of people who were involved in the program," he told me. "There's a consciousness that this might be the last hurrah. Hopefully not. Hopefully, we'll have a bigger celebration for the 50th. Hopefully, we'll be on the moon.

    "But hopefully, there won't be a lot more books," Pearlman added. "For a reviewer like me, that's just a lot more reading."

    More fun stuff for the Summer of Apollo:

    Update for 3:45 p.m. ET June 9: I've added information about the 16mm film imagery of moonwalker Neil Armstrong. For further details, check out CollectSpace's report..

    Stay tuned for future roundups of video and online resources for the 40th anniversary of Apollo 11. Join the Cosmic Log corps by signing up as my Facebook friend or hooking up on Twitter. And if you really want to be friendly, ask me about my upcoming book, "The Case for Pluto." 

  • How animals laugh

    Miriam Wessels / Univ. of Veterinary Medicine
    Click for video: An orangutan named Naru vocalizes during a tickling session.
    Click on the image to watch what happens when a gorilla is tickled in captivity.

    How do you graph the evolution of a laugh? Researchers tickled babies and six different kinds of apes, quantified their giggles, and found that the patterns fit a classic evolutionary tree.

    Those patterns hint at the ancient origins of human hilarity and suggest that other social species - including apes, dogs and rats - really, truly laugh as well.

    "What we can say is that laughter goes back at least 10 to 16 million years," said University of Portsmouth primatologist Marina Davila Ross, one of the researchers behind the study published online today in the journal Current Biology. "It could go farther than that."

    A prominent researcher in the specialized field of animal laughter, Jaak Panksepp of Washington State University, said it definitely goes farther back than that. "I personally think that a credible laughter concept can, and already has been, extended to mammalian species as lowly as the rat," he told me in an e-mail.

    For years, Panksepp and his colleagues have been documenting the high-pitched vocalizations that rats make when they're tickled by human handlers - and they insist that such vocalizations reflect "laughter and social joy." But some skeptics have said it's too much of a stretch to classify those sounds as true laughter.

    The research conducted by Davila Ross and her colleagues - Georgia State University's Michael Owren and Elke Zimmermann of the University of Veterinary Medicine in Hannover, Germany - appears to support the case for animal laughter. The scientists charted a spectrum of tickle-induced vocalizations from three human infants and four species of great apes in captivity, plus the less closely related siamang ape.

    Eleven auditory variables were measured for the 25 experimental subjects - variables such as the length of the vocalization, the in-and-out breathing patterns and the vibrations of the vocal cords. All those numbers were fed into a software program that looked for relationships between the data points. Then the computer constructed a phylogenetic tree (that is, the "family tree") that fit the data best.

    The resulting tree turned out to reflect the widely accepted evolutionary relationships between the species. The siamang was way out on its own branch. Chimpanzees and bonobos were closely related to each other, and to humans. Gorillas branched out a bit lower on the tree, and orangutans were lower still.

    "It's an interesting pattern," Davila Ross said. The human babies had a distinctive pattern of laughter: a haa-haa-haa, with regular voicing, on the exhale only. But the researchers could see the roots of that pattern in the chimp vocalizations: typically, a fast hee-uh-hee-uh-hee, using an in-and-out airflow.

    Listen to the tickle-induced laughter from five of the species that were studied, as captured in audio clips from the University of Portsmouth:

    The researchers were surprised to find that some of the apes could extend their exhalation to as long as 10 seconds during laughter. "That's something that was thought to be present only in humans," Davila Ross said. "It's certainly an important part of speech - that we can produce a continuous vocal flow without having to stop, inhale, and say a few more words again."

    In their Current Biology paper, the researchers say "one can conclude that it is appropriate to consider 'laughter' to be a cross-species phenomenon, and that it is therefore not anthropomorphic to use this term for tickling-induced vocalizations produced by the great apes."

    Laughter around the animal world
    Panksepp said the paper "provides a minimalist, highly conservative interpretation of the exciting findings." He's been focusing on rats, but other research suggests that dogs make a particular kind of pant that could be considered laughter. The "dog-laugh" accompanies play behavior, and when other dogs hear the sound, it appears to reduce stress (like a good joke among humans).

    One of Panksepp's research colleagues, Northwestern University's Jeffrey Burgdorf, said rat laughs seem to have a similar effect ... on rats, that is. "These animals like to hear them," he told me. "They press a bar to hear these vocalizations. ... Every time they vocalize, it's rewarding to them."

    Burgdorf sees the evidence of that in the rats' neurochemical response as well. Laughing, or even hearing laughter, leads to the release of dopamine and opiates that make the brain feel good.

    The more socially oriented a species is, the more likely it is to exhibit laughter (or, more technically, vocalizations associated with tickling or play). Rats laugh, but not mice. "Mice are solitary creatures," Burgdorf said.

    OK, so what about cats? Could purring be considered laughter? "My gut says that it is, but you can't show it empirically," Burgdorf said. If researchers find that a cat's purr is associated with the brain's feel-good chemicals, that might support the case for feline laughter. But really, the bottom line is that there's a wide spectrum of vocalizations linked to animal pleasures.

    "Invertebrates make vocalizations, but they don't have neuroanatomical homology to humans," said Burgdorf, sounding thoroughly like the neuroscientist he is. Translation: Just because a bee buzzes, that doesn't mean it's laughing at you.

    Evolution of laughter
    The latest research doesn't speculate on what drove the evolution of laughter. "It could be that there are social factors that have had an impact on evolution," Davila Ross said. "There could be side effects of the evolution of vocalization and speech."

    The apes were recorded during tickling sessions at seven European zoos, and Davila Ross acknowledged that laughter in the wild could be different from laughter in captivity. "Even if you compare one zoo group with another zoo group, there are differences," she said. But the researchers tried to minimize the potential for human influence by tickling infants and juveniles rather than adult apes.

    Vocalizations associated with pleasure could serve as positive signals to other members of the species during social interactions. "It probably came from mating vocalizations, which are examples of positive social interactions," Burgdorf said.

    Burgdorf said he's interested in laughter not so much to find out how it evolved, but to find out how it can heal. If there's a link between particular types of vocalizations and the neurochemistry of feeling good, then animal studies could lead to better mood-lightening medicines.

    Studying animal laughter certainly lightened the mood of Davila Ross and her colleagues: "When watching the apes play with the caretakers, it was contagious," she said.

    For more mood lighteners, check out our roundups of zoo babies and oddball animals, plus this video of a giggling gorilla.

  • Will Mars rover roll again?

    NASA / JPL / USGS
    This image shows the underbelly of NASA's Spirit rover, as seen by the rover's microscopic imager on June 2. One wheel can be seen at left, another buried wheel
    is at right, and a pointed shape that may be an obstruction is at center. The picture
    is fuzzy because the camera was not designed to take these types of images, and
    it is tipped to reflect the rover's orientation relative to the local terrain.

    NASA experts are taking fuzzy pictures and trying out different recipes for Red Planet dirt as they continue their weeks-long effort to get a stuck Mars rover moving again.

    It's been more than three weeks since the Spirit rover became mired in loose dirt on the west side of the Martian feature known as "Home Plate." During that time, the mission team at NASA's Jet Propulsion Laboratory has fielded scores of suggestions for freeing up Spirit, rover project manager John Callas told me today.

    Callas said he and his colleagues have heard from "farmers who have had tractors stuck in the mud and figured out how to get them out," as well as a 7-year-old boy named Julian who suggested having Spirit push itself out with its robotic arm.

    The ideas are much appreciated, Callas said, but "we still have many arrows in our quiver before we have to consider more drastic operations."

    Right now, Spirit is using its arm for subtler purposes: The microscopic imager on the end of the arm is being pointed under the rover's belly to size up the situation. "The images are out of focus, but they exhibit enough detail that we can tell quite a bit," Callas said.

    The latest images suggest that Spirit might be high-centered on an obstruction - sort of like a car whose undercarriage is hung up on a rock. "We see something underneath the rover," Callas said. "It's hard to tell in the image whether the object is under the rover or in front of it, or if it's one object or two. ... It's rather pointy. It's pyramid-like."

    That's the bad news. The good news is that Martian winds have swept the dust off Spirit's solar panels, easing mission planners' worries that they would soon have to hustle the rover to a sun-facing safe haven. "With this dust cleaning that we've had, that has greatly relieved the urgency to get the rover going anywhere," Callas said.

    In addition to taking pictures, engineers at the Jet Propulsion Lab are working on a test bed where they can try out maneuvers to free the rover. So far, they've figured out that the soft soil where Spirit is stuck contains ferric sulfate. "There may be some sort of surface crust, and this may have been what got us into trouble," Callas said. The rover might have been like a hiker walking over hard-packed snow: If you break through the crust to the softer stuff below, pulling yourself out can be a tough job.

    NASA / JPL
    A worker at NASA's Jet Propulsion Laboratory digs simulated Martian soil in an effort to replicate the Spirit rover's situation on the Red Planet.

    Experts have been trying to mix up simulated soil that duplicates the properties of Spirit's sand trap, but so far they haven't found the right formula. Once they find it, "we'll order up tons of this material and essentially do some landscaping, and shovel it into this test bed," Callas said.

    "It's likely we'll want to just drive forward with the rover, but we want to make sure we don't make things worse," he said.

    Figuring out the best course and giving it a try will almost certainly take weeks longer. When Opportunity got caught in a sand trap four years ago, the wheels had to spin for the equivalent of 200 meters (yards) before the rover popped out of the trench it had dug for itself, Callas said. The current situation is even more challenging, in part because one of Spirit's six wheels has been out of commission for years and must be dragged along wherever the rover goes.

    "This is probably the most serious embedding that either rover has experienced," Callas said. "There is a very real risk of Spirit being permanently stuck. If that were the case, then we become a fixed lander. But we have a lot of options still, a lot of techniques to apply to this problem."

    While the engineers work all that out, the scientists are using Spirit's instruments to make a detailed survey of its surroundings. They're analyzing the soil, creating a 360-degree panorama of the area, and seeing a side of Home Plate they've never had the chance to explore before.

    "We've never taken the time to smell the roses, so to speak," Callas said.

    Nothing has come easy for Spirit: Just days after the rover landed, it suffered a serious reset that took two weeks to repair. Losing the wheel was a big setback. And there was a time when it looked as if the rover would run out of power. More recently, Spirit suffered a worrying series of senior moments, but the faulty memory has apparently been fixed.

    "None of that has returned," Callas said. "We still don't know the origin of it."

    If Spirit manages to work its way out of its current fix, it could rank as the rover's greatest escape yet. And even if Spirit remains stuck, it will still be sending back valuable science data until it slowly fades into the Martian sunset. That's not a bad way to go ... particularly when you consider that NASA expected the rover to last just 90 days rather than the current 1,925-and-counting.

    Each day makes the Mars missions more of a bargain: The price tag for the twin rovers' original primary mission was $820 million. Five years and five extensions later, the cost still hasn't come up to the $1 billion ballpark figure for a single space shuttle mission.

    Update for 1:10 p.m. ET June 5: I've added the panorama showing Spirit's underbelly, which was released after this item was first published.

  • Watching science on the Web

    msnbc.com
      Click for video: The
      primate fossil known
      as "Ida" has caused
      a scientific stir.

    A growing number of online ventures are serving up regular doses of science video to fill the gaps in TV coverage - including some ventures that are led by media-hopping TV types.

    The latest entrant in the field is "Science Nation," a weekly video series funded by the National Science Foundation and created by former CNN producers. The first installment, released Monday, focuses on Earth's "alien" species - that is, extremophile organisms that can survive in Antarctica's frozen deserts or volcanic vents at the bottom of the ocean.

    You'll find video clips that focus on NASA researcher Richard Hoover's work as well as a feature story by CNN alumna Kate Tobin and an extremophile slideshow. Another ex-CNNer, Peter Dykstra, is also contributing to the project. Future installments of "Science Nation" will explore the science of tornadoes, artificial retinas, hydrogen cars and environmental cleanup in rural China. NSF's news release provides more of a preview.

    Miles O'Brien, another widely respected science/space journalist who was forced out of the CNN fold, has several irons in the fire: You can watch him hold forth on the nation's infrastructure crisis on PBS' "Blueprint America" series. You can read his "Uplinks" blog at True/Slant. And during last month's Hubble repair mission, he did the anchoring duties for Spaceflight Now's online video coverage.

    All this is just the tip of the video iceberg: Here are the beginnings of a mini-TV guide for science video online. Please feel free to pass along your favorites as comments, and I'll add them to the list:

    Join the Cosmic Log corps by signing up as my Facebook friend or hooking up on Twitter. And if you really want to be friendly, ask me about my upcoming book, "The Case for Pluto." 

  • Notable in New Space

    • NASA has announced the full lineup for an independent committee tasked with reviewing the space agency's plans to retire the shuttle fleet, build a new line of spaceships and return to the moon. The panel is headed by retired aerospace executive Norm Augustine, but its members also include a leading space entrepreneur, XCOR Aerospace CEO Jeff Greason. Today's official list also includes two former astronauts (Sally Ride, first American woman in space; and Leroy Chiao, former space station commander) as well as two former prospects for NASA's top post (retired Air Force Gen. Lester Lyles and Earth scientist Charles Kennel). The committee's first meeting is set for later this month.
    • The name of a Canadian entrepreneur who is due to fly as a paying passenger to the international space station in September will be announced simultaneously in Montreal and Moscow on Thursday, Virginia-based Space Adventures says. The seat opened up when Kazakhstan canceled its plans to send a trained cosmonaut on that flight, as reported by Reuters last month. The quoted rate for a reservation on Russia's Soyuz spaceship is $35 million, or maybe even more by now. The Itar-Tass news agency quoted Russian space chief Anatoly Perminov as saying that "this form of tourism will continue" - which was an expected reversal of his previous position that space millionaires would no longer be flown. So who's the Canadian space traveler? Let the guessing game begin. (I'll guess Stewart Blusson.)

    Update for 12:15 p.m. June 2: NASA Watch seems to have a more informed guess: Cirque du Soleil founder and CEO Guy Laliberté.

    • California-based SpaceX says its next Falcon 1 launch, which would put Malaysia's RazakSat Earth-observing satellite into orbit, has been rescheduled for July 13 or 14.
    • Aviation Week delves more deeply into the SpaceShipTwo rocket motor tests that came to light last week. The rocket ship itself is due to roll out later this year.

  • Mystery over the Atlantic

    Z. Kawasaki / Osaka U. via NWS
    Lightning strikes a plane over an
    airport in Japan in 1997. Click on
    the image for an animated version.

    Did lightning alone bring down Air France 447? Or were there complicating factors?

    Solving the mystery surrounding the jet's trans-Atlantic disappearance is more challenging because there's no radar, no witnesses, no easy-to-find debris field.

    But similar mysteries have been solved over the past couple of decades, thanks to some heavy-duty underwater sleuthing.

    The four-year-old Airbus A330 jet and its 228 passengers and crew members were lost over the Atlantic Ocean during a Rio-to-Paris flight on Sunday night, in the midst of a towering storm. No distress call was heard. The only hint of trouble was an automated notification of an electrical failure and loss of cabin pressure, radioed to a monitoring station.

    Satellite imagery indicates that vigorous thunderstorms were swirling through the tropical zone where the plane was flying - storms that the plane just couldn't go around. The jet could have been felled by a lightning strike, or by extreme turbulence and wind shear, or icing, or equipment failure, or a combination of those factors.

    Although lightning has been listed as the likeliest suspect, no one really knows for sure, because authorities haven't yet located the wreckage - let alone the flight voice and data recorders that could tell the tale.

    Bill Voss, president and chief executive officer of the Virginia-based Flight Safety Foundation, said the jet was designed to withstand the jolt. "Lightning strikes are really not that uncommon ... but I can't remember the last time lightning brought an airplane down," Voss told me. Such occurrences are few and far between.

    Can the mystery be solved? Voss thinks so. "There's a good chance we're going to be able to find that thing," Voss said.

    But it won't be easy. Based on the plane's telemetry, they surmise that the jet was downed over deep ocean 745 miles northeast of the Brazilian coast. Assuming that recovery teams spot the wreckage or detect the "ping" emitted by the flight recorders, someone ... or something ... will have to bring up the black boxes, plane debris and any remains that could be reclaimed from the sea.

    "There's only a handful of companies that can do this kind of deep-water work," Voss said. Remotely operated vehicles will likely play a big role.

    The authority in charge of the investigation is France's air safety agency - the BEA (which is short for Bureau d'Enquêtes et d'Analyses pour la sécurité de l'Aviation Civile, or Bureau of Inquiry and Analysis for Civil Aviation Safety). "That's a very serious accident [investigation] agency," Voss said.

    Because the plane is assumed to have gone down in international waters, the BEA is already working with Brazilian searchers and has asked for assistance from the U.S. National Transportation Safety Board. In turn, the NTSB is asking all federal agencies, civilian and military, to provide any information that could help with the search. That could include military or spy satellite data, or radar readings.

    Private companies will most likely be brought in to help with the recovery as well.

    If the history of at-sea air crashes is any guide, cracking the case could take months or years, and there could be some surprises along the way. Here are four examples:

    • Air India 182: The Boeing 747 crashed into the Atlantic off the coast of Ireland in 1985, leading to 389 deaths. Remotely operated vehicles recovered the flight recorders about two weeks after the crash, and international investigations concluded that the downing was caused by a bomb planted by Sikh separatists.
    • TWA 800: The Boeing 747 went down into the Atlantic near Long Island during a New York-Paris flight in 1996, killing 230. Navy divers made nearly 700 dives to assist in the investigation. After three years of analysis, the NTSB blamed a wiring problem that sparked an explosion in one of the jet's fuel tanks (although conspiracy theorists still suspected foul play). The report led to design modifications in the 747.
    • Swissair 111: The McDonnell Douglas MD-11 was lost during a New York-Geneva flight in 1998 over the Atlantic near Nova Scotia, killing 229. A sonar-equipped sub quickly located the flight recorders, and divers brought them up less than two weeks after the crash. Canadian investigators determined that faulty wiring, perhaps inside the in-flight entertainment system, caused an electrical fire that spread through flammable material so quickly the crew couldn't stop it.
    • Adam Air KI-574: The Indonesian Boeing 737 went down in 2007, killing 102, and it took almost eight months to retrieve the flight recorders from the Makassar Strait. Indonesian investigators concluded that the plane crashed because pilots inadvertently disconnected the autopilot.

    One of the biggest challenges for searchers has been the fact that the Air France plane couldn't show up on radar tracking as it passed over the Atlantic. "The problem with radar is, you can't put a radar station over water," said Paul Takamoto, a spokesman for the Federal Aviation Administration. You can get radar readings from orbiting satellites, but not from land-based installations.

    That situation is changing, however, thanks to the Global Positioning Satellite system. The FAA is phasing in a GPS-based air traffic monitoring system known as ADS-B (that is, Automatic Dependent Surveillance-Broadcast). The system was pioneered by the FAA's Canadian counterpart, Nav Canada, and it's now being used in Alaska and south Florida.

    Takamoto said ADS-B was introduced in Alaska first "because large parts of that state do not have radar coverage because of the rugged terrain." The satellite navigation system led to a 47 percent reduction in fatal air accidents in the state, he said.

    ADS-B is slated to go nationwide by 2013, and if it takes hold internationally, the system will likely lead to safer and far more efficient air travel over the Atlantic, the Pacific and the Gulf of Mexico, Takamoto said. Here's why: Today, airplanes making their way across those radar dead zones have to be spaced roughly 10 minutes or 100 miles apart, to reduce the risk of collision. When the new system is phased in, pilots and controllers will be able to watch every move, even in places too remote for radar.

    And that should make the skies a lot friendlier for planes passing over the sea.

    Update for 8:50 p.m. ET: A big shout-out to NBC News' Tom Costello for sending facts my way. Here's his video report for "Nightly News."

    Update for 10:30 p.m. ET: Spaceflight Now's Craig Covault reports that readings from the U.S. Air Force's Defense Support Program satellites are being analyzed for any signs of a flash from the jet's breakup or impact. As Costello has reported, authorities are checking other military satellite data as well.

    Correction for 5 p.m. ET June 3: The TWA Flight 800 crash occurred in 1996, not 1997. I've corrected the reference above. Apologies for the error.

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