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  • richardmitnick 10:42 am on January 16, 2019 Permalink | Reply
    Tags: , , , , Disintegrating Planets Could Be the Key to Discovering What Worlds Are Made Of, Smithsonian.com   

    From smithsonian.com: “Disintegrating Planets Could Be the Key to Discovering What Worlds Are Made Of” 

    From smithsonian.com

    January 15, 2019
    Nola Taylor Redd

    The artist’s concept depicts a comet-like tail of a possible disintegrating super Mercury-size planet candidate as it transits its parent star named KIC 12557548. At an orbital distance of only twice the diameter of its star, the surface temperature of the potential planet is estimated to be a sweltering 3,300 degrees Fahrenheit. (NASA / JPL-Caltech)

    The exoplanet Kepler-1520b is so close to its host star that it completes an orbit in just over half a day. At this close proximity, Kepler-1520b is tidally locked in a gravitational stability, keeping one half of the planet facing the star and the other half facing away at all times. Unfortunately for Kepler-1520b, this arrangement turns the star-facing side of the planet into a churning mass of molten rock and magma seas, slowly boiling off into space.

    Even though Kepler-1520b is not long for this galaxy, astronomers are eager to learn more about the disintegrating world, positioned about 2,000 light-years from Earth. The planets’ comet-like tail of dust and debris could provide insight into the fundamental formation process of all planets in the galaxy. New telescopes, such as NASA’s James Webb Space Telescope scheduled to launch in 2021, may be able to probe the cloud behind Kepler-1520b and two other slowly disintegrating worlds.

    NASA/ESA/CSA Webb Telescope annotated

    “The composition in an exoplanet system could be substantially different from the solar system,” says Eva Bodman, an exoplanet researcher at Arizona State University. As more and more exoplanets are discovered, astronomers are struck by how unique our solar system looks from other planets orbiting other stars. Bodman set out to determine if it was possible to measure the composition of a small, rocky, disintegrating exoplanet by studying the debris traveling in its wake. But there was a problem.

    Spotting the fingerprint of rocky elements requires studying the worlds in infrared. Ground-based telescopes aren’t sensitive enough to spot them, leaving only NASA’s soon-retiring Spitzer Space Telescope and SOFIA, a telescope carried above the atmosphere on board a Boeing 747.

    NASA/Spitzer Infrared Telescope


    Neither instrument has the range to look for the rocky material, Bodman says. But James Webb, designed to study exoplanets in infrared as well as ancient galaxies and the most distant objects of the universe, should be able to peer through the clouds of debris and identify some of their ingredients.

    “Webb would be able to measure the relative abundances of different minerals,” Bodman says. “From that, we can infer the geochemistry of the interior of these planets was before they started disintegrating.” Bodman and her team’s findings on the feasibility of studying disintegrating exoplanets were published in The Astronomical Journal late last year.

    In 2012, scientists reviewing data from NASA’s Kepler space telescope found signs of a world being slowly shredded by heat and pressure, Kepler-1520b. Two more shredded planets were found in the following years among the thousands of exoplanets discovered by Kepler and its extended mission, K2. Circling their stars in just a handful of hours, these rocky bodies boast temperatures as high as 4,200 degrees Celsius (7,640 degrees Fahrenheit) on the superheated regions facing the stars.

    The extreme temperatures drive the planet’s dissolution. “The atmosphere is just rock vapor,” Bodman says. “It’s the sheer heat of the planet that’s pushing off this rock vapor atmosphere.”

    Radiation produced by the stars pushes against the planet’s vaporized atmospheres, creating a cloudy tail. Although Kepler wasn’t able to directly measure how large the shrouded planets were, simulations suggest that they are between the size of the moon and Mars. Any more compact, and the disintegration process shuts down.

    These objects were not always so small and shriveled, however. Kepler-1520b and the two other objects like it are thought to have formed as gas giants, after which they migrated in toward their host stars and were stripped all the way down to the rocky core.

    In recent years, exoplanet scientists have made great strides studying the atmospheres of large, gaseous planets orbiting other stars. Most of that material is rich in hydrogen and helium and can be identified using NASA’s Hubble Space Telescope. But the rocky materials fall on a different part of the spectrum, “in wavelengths that Hubble can’t currently reach,” says Knicole Colon, a research astrophysicist at NASA’s Goddard Space Flight Center in Maryland who has studied the disintegrating planet K2-22. “With James Webb, we’d be able to go out to those wavelengths.”

    Using Webb to hunt for materials such as iron, carbon and quartz, astronomers would gain a better understanding about what’s going on inside distant worlds. “If we were able to detect any of these features, we could say with some certainty what these rocky bodies are made off,” Colon says. “That could definitely be very informative for understanding rocky exoplanets in general.”

    Planets form from the cloud of dust and gas leftover after the birth of a star. Scientists think the worlds of the solar system were created by a process known as pebble accretion, in which small bits of dust and gas come together to make larger and larger objects. Eventually, the cores of the gas giants grow massive enough to attract leftover gas, forming their thick atmospheres. But the exact steps remain difficult to pin down.

    The interiors of planets around other stars would vary depending on the elements found in that particular environment. Sorting through these differences could help researchers better understand those tantalizing first steps of planet formation.

    “There’s no reason that the solar system should be different from exoplanets, and vice versa,” Colon says. “We’re all planets, so we all formed in possibly similar ways. Understanding these planets is another step in the process to the bigger picture.”

    But even with similar formation processes, Bodman suspects that planets around other stars might not look so familiar. “The composition in an exoplanet system could be substantially different from the solar system,” she says.

    Although Webb will only be able to tease out information about exoplanet composition, advanced instruments may one day allow disintegrating planets to reveal even more about themselves. As the planets erode away, astronomers could get an unprecedented look at their interiors, possibly down to the core. “In theory, we could know more about these exoplanets than even about the Earth, and definitely more than the other planets in the solar system,” Bodman says.

    Unlike stars, which can shine for tens of billions of years, shredded worlds only stick around for a relatively short time. Simulations suggest that planets like K2-22 only have about 10 million years before they are completely destroyed. And because all three worlds orbit stars that are billions of years old, they probably haven’t been in their current positions for very long.

    Bodman and Colon both think the doomed planets probably formed far out in their system and then migrated inward over time. Interactions with other planets could have hurled them on their fateful trajectories, although all three of these disintegrating planets are the only known satellites of their host stars. Bodman says it is likely the worlds have only recently begun a close orbit of their stars, but how they got there remains an open question.

    The short lifetime of a disintegrating planet—only a blip in the longer life of a star—is probably why so few of these worlds have been found. “They’re definitely rare,” Bodman says.

    Both women agree that there is a good chance that another one or two disintegrating exoplanets are contained in the Kepler data, especially the most recent results from K2. And the recently launched Transiting Exoplanet Survey Satellite (TESS), which has already found hundreds of new planets, will produce even more.

    “I think it’ll take some time to sift through everything, but I’m hoping we find more,” Colon says.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Smithsonian magazine and Smithsonian.com place a Smithsonian lens on the world, looking at the topics and subject matters researched, studied and exhibited by the Smithsonian Institution — science, history, art, popular culture and innovation — and chronicling them every day for our diverse readership.

  • richardmitnick 10:51 am on January 9, 2019 Permalink | Reply
    Tags: , , , China’s Chang’e-4 lander, , , Smithsonian.com   

    From smithsonian.com: “Best Photos From China’s Far Side Moon Landing” 

    From smithsonian.com

    January 7, 2019
    Jason Daley
    All photos from China National Space Admimmistration

    Yutu-2 rover leaves the Chang’e-4 lander

    Yutu-2 sets off.

    First images

    Close shot of Yutu-2 rover specialized wheel.

    China’s Chang’e-4 lander reached the Von Kármán crater near the moon’s South Pole on Wednesday, marking the first time a human craft has visited the lunar far side.

    The first upclose images of the far side’s surface came in shortly after via a satellite called “Queqiao,” report Steven Lee Myers and Zoe Mou at The New York Times.

    Queqiao Relay Satellite China

    The Guardian reports that, about 12 hours after the landing, a small rover named Yutu-2, or Jade Rabbit-2, left the Chang’e-4 spacecraft and began exploring the crater, which is part of the South Pole-Aitken basin, one of the largest known impact structures in our solar system.

    Chang’e-4 weighs about four metric tons and carries eight instruments on board, including an infrared spectrometer, panoramic camera and lunar penetrating radar, writes Andrew Jones at Smithsonian.com. It will also collect mineral and geological samples of the moon’s surface as well as investigate the impact of solar wind on the moon. The craft even has its own little farm, or lunar biosphere, aboard—the first of its kind. Part of an experiment designed by university students, it contains silkworm eggs, potato seeds and Arabidopsis, a model organism used in space plant studies.

    Because the far side of the moon is shielded from the radio signals coming from Earth, Chang’e-4 will conduct low frequency radio experiments using a new technique. Astronomers plan to connect a radio instrument on the landing craft with one aboard the Queqiao satellite and use the dual-system as a radio telescope—free from noisy radio interference that is common closer to Earth, reports Michael Greshko at National Geographic.

    “This will allow us for the first time to do radio observation at low frequencies that are not possible from Earth, from close to the moon and on the moon,” Radboud University astronomer Marc Klein Wolt, who leads the project, tells Greshko. “This will pave the way for a future large radio facility on the moon to study the very early universe in the period before the first stars were formed.”

    While such experiments are valuable, the landing is also considered an important accomplishment for the Chinese space program, which is quickly catching up to the decades-old United States and Russian space programs. Landing on the far side required a high level of technical expertise and unique communications solutions, Smithsonian.com’s Jones points out.

    “This is a major achievement technically and symbolically,” Namrata Goswami, an independent space analyst, tells The New York Times. “China views this landing as just a stepping stone, as it also views its future manned lunar landing, since its long-term goal is to colonize the moon and use it as a vast supply of energy.”

    In the last two decades, China has ramped up its space program, launching two space stations and sending dozens of satellites into space. Besides the U.S. and Russia, it is the only nation to send its own astronauts into space. It first visited the near side of the moon in 2013 with its Chang’e-3 lander and rover. Later in 2019, the nation plans to land Chang’e-5 on the near side of the moon and then send a sample of the moon’s surface back to Earth. In 2022, China is slated to launch another space station into orbit and has plans to establish a lunar colony later in that decade.

    While the success of Chang’e-4 is being universally celebrated by the scientific community, space policy expert Wendy Whitman Cobb at The Conversation wonders whether its an indication of second space race. The U.S. recently announced a 10-year, $2.6 billion effort to return to the moon and construct an orbiting space station. Russia has also announced intentions to send missions to the moon in the near future.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Smithsonian magazine and Smithsonian.com place a Smithsonian lens on the world, looking at the topics and subject matters researched, studied and exhibited by the Smithsonian Institution — science, history, art, popular culture and innovation — and chronicling them every day for our diverse readership.

  • richardmitnick 11:17 am on December 4, 2018 Permalink | Reply
    Tags: 40000000000000000000000000000000000000000000000000000000000000000000000000000000000000 photons over 13.7 billion years, , , , EBL-extragalactic background light, Looking at blazars ranging in age from 2 million to 11.6 billion years old, , Smithsonian.com, This Is How Much Starlight the Universe Has Produced   

    From smithsonian.com: “This Is How Much Starlight the Universe Has Produced” 

    From smithsonian.com

    4,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000,000,000,000,000,000,000,000,000 photons over 13.7 billion years.

    December 3, 2018
    Jason Daley

    Extragalactic Background Light ( Fermi-LAT)

    NASA/Fermi LAT

    NASA/Fermi Gamma Ray Space Telescope

    Since the first stars first started flickering about 100 million years after the Big Bang our universe has produced roughly one trillion trillion stars, each pumping starlight out into the cosmos. That’s a mind-boggling amount of energy, but for scientists at the Fermi Large Area Telescope Collaboration it presented a challenge. Hannah Devlin at The Guardian reports that the astronomers and astrophysicists took on the monumental task of calculating how much starlight has been emitted since the universe began 13.7 billion years ago.

    So, how much starlight is there? According to the paper in the journal Science, 4×10^84 photons worth of starlight have been produced in our universe, or 4,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000,000,000,000,000,000,000,000,000 photons.

    To get to that stupendously ginormous number, the team analyzed a decades worth of data from the Fermi Gamma-ray Space Telescope, a NASA project that collects data on star formation. The team looked specifically at data from the extragalactic background light (EBL) a cosmic fog permeating the universe where 90 percent of the ultraviolet, infrared and visible radiation emitted from stars ends up. The team examined 739 blazars, a type of galaxy with a supermassive black hole in its center that shoots out streams of gamma-ray photos directly toward Earth at nearly the speed of light. The objects are so bright, even extremely distant blazars can be seen from Earth. These photons from the shiny galaxies collide with the EBL, which absorbs some of the photons, leaving an imprint the researchers can study.

    Looking at blazars ranging in age from 2 million to 11.6 billion years old allowed the researchers to use the sensitive instruments on the Fermi telescope to analyze their light, measuring how much radiation it lost as it moved through the EBL. This let them create an accurate measure of the density or thickness of the EBL over time, essentially creating a history of starlight in the universe since, in deep space, distance and time are almost the same thing.

    “By using blazars at different distances from us, we measured the total starlight at different time periods,” co-author Vaidehi Paliya of Clemson University says in a press release. “We measured the total starlight of each epoch – one billion years ago, two billion years ago, six billion years ago, etc. – all the way back to when stars were first formed. This allowed us to reconstruct the EBL and determine the star-formation history of the universe in a more effective manner than had been achieved before.”

    Researchers have tried to measure the EBL in the past, but were unable to get past the localized dust and starlight close to Earth, making it almost impossible to collect good data on the EBL. The Fermi telescope, however, finally allowed the team to minimize that interference by looking at gamma rays. The data they collected is in line with previous estimates for the density of the EBL.

    The study shows that the peak of star formation in the universe took place about 11 billion years ago. Over time, it has slowed drastically, but stars are still forming, with about seven new stars lighting up in the Milky Way every year alone.

    The study was not just an exercise in smashing the zero key either. Ryan F. Mandelbaum at Gizmodo reports that the measurement gives scientist an upper limit to the number of galaxies that were floating around 12 billion years ago during the Epoch of Reionization, the period when dark matter, hydrogen and helium first coalesced into stars and ordinary matter. It’s also possible that the EBL measurement could help develop new ways to look for unknown particle types.

    Clemson astrophysicist and lead author Marco Ajello says in the release that the study is also good step toward understanding the universe’s earliest days

    “The first billion years of our universe’s history are a very interesting epoch that has not yet been probed by current satellites,” he says. “Our measurement allows us to peek inside it. Perhaps one day we will find a way to look all the way back to the big bang. This is our ultimate goal.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Smithsonian magazine and Smithsonian.com place a Smithsonian lens on the world, looking at the topics and subject matters researched, studied and exhibited by the Smithsonian Institution — science, history, art, popular culture and innovation — and chronicling them every day for our diverse readership.

  • richardmitnick 9:50 am on July 18, 2018 Permalink | Reply
    Tags: , , , , Dana Berry, , Smithsonian.com,   

    From smithsonian.com: “The Supernova That Launched a Thousand Gorgeous Space Images” Dana Berry 

    From smithsonian.com

    July 17, 2018
    Casey Rentz

    Berry started his career colorizing actual telescope data. His more recent work includes this artistic impression of a black hole at the heart of galaxy NGC 1068. The material trapped around the black hole is moving so fast that the light itself is either compressed to blue where the material is coming toward the viewer, or stretched to red, where it is rushing away from the viewer. (Dana Berry / SkyWorks / NRAO / NSF)

    In 1990, Dana Berry was messing around with a precursor to the software program Photoshop at NASA’s Space Telescope Science Institute, where he worked as a science visualizer.

    Space Telescope Science Institute operated for NASA by AURA

    The Hubble Telescope had launched that year, and all around him, the Institute’s scientists were busy analyzing and releasing about a half dozen deep space images. But all were grainy and monochrome—not exactly ideal for conveying the dazzling mystery of the cosmos.

    One day, astrophysicist Eric Chaisson walked over to Berry’s office with a picture of a supernova exploding. It was a remarkable event to be caught on camera, but the black-and-white palette did it no justice. Chaisson suggested that Berry colorize the image, mostly for the wow-factor. He argued that color was scientifically justifiable since the supernova actually did reflect colored light, but Hubble’s camera was only set to capture light at 5007 angstroms.

    Berry sat down to his Silicon Graphics Iris 3130 computer—bigger than a mini-fridge with less computing power than the original iPhone—and began toying with the image.

    Silicon Graphics Iris 3130

    “I frankly couldn’t believe my good fortune that I was doing this,” Berry says now.

    In keeping with Chaisson’s request, he colored the blob in the center pink because to represent hydrogen, which glows magenta when it burns in the laboratory. He colored the ring yellow because it emitted sulfur, which burns yellow in the lab. He colored the two stars on either side a kind of pool blue because hot stars burn either blue or white/blue. Berry was tempted to add small, distant stars in the background like you would see if the camera could’ve focused on the whole scene at once, but decided against it: “I handled that image as gingerly as I could, as if the scientific data was holy in a way,” he says.

    Berry shooting Hubble’s Amazing Universe for National Geographic in 2008. (Dana Berry)

    Berry’s admiration for NASA exploration went deep. When he was young, he followed the Apollo missions with great zeal. One day he and his father learned that one of the Apollo capsules would reenter the atmosphere and splash down over the Atlantic somewhere between their hometown, Myrtle Beach, SC, and Puerto Rico. They drove to the beach and looked out over the ocean for hours. Once, they swore they saw a white streak grace the sky. Berry was also inspired by Carl Sagan’s 1980 documentary Cosmos. In college, he majored in art but took as many astronomy courses as he could. In astronomy, “I could see these things I was reading about,” he says.

    In 1987, he had graduated and was making PowerPoint graphics for businesses when he saw an ad for the job at the Space Telescope Science Institute. They were looking for a computer scientist, but he interviewed anyway and, as he puts it, “talked his way into the job.” When the first images started coming through, he and everyone at the Institute immediately started contemplating how they could be best used.

    At the time, the space program was facing significant challenges. By the time Hubble launched, it had cost more than $2 billion and had the unfortunate timing of being the next big project to come after the space shuttle Challenger, which had exploded over onlookers in Florida. Everyone was watching Hubble. To add to the anxiety, scientists discovered post-launch that Hubble’s main mirror had a manufacturing defect.

    News media ridiculed NASA, and Hubble became the butt of Jay Leno’s late-night jokes. “What sound does a space turkey make? Hubble, Hubble, Hubble,” the comedian quipped on an early 1990’s broadcast.

    The first Hubble color image of Supernova 1987A, colored by Berry, was released to news media on August 29, 1990, and immediately mesmerized astronomy lovers and piqued the interest of the general public.

    A String of ‘Cosmic Pearls’ Surrounds an Exploding Star

    Hubble’s first colorized space image was this image of a supernova taken with the European Space Agency’s Faint Object Camera on August 23, 1990. (Dana Berry / Space Telescope Science Institute)

    The chatter among scientists was not all positive, though, Berry recalls. Some said the picture was not strictly accurate; artistic license had been taken with the color additions.

    But beyond translating the science, Supernova 1987A and other images served another key purpose as well. They showed off what Hubble could do—that is, capture amazing images that ground telescopes couldn’t—and re-ignited the public interest in space exploration. “The value of the public outreach was not understood in the general scientific community,” Berry says, “but that changed and I think Hubble was a catalyst for that change.”

    Other institutions took notice. After several years at the Space Telescope Science Institute, Berry took a job at Tufts University and then at NASA’s Chandra X-ray Observatory, which is headquartered at the Smithsonian Astrophysical Observatory, where he used similar techniques to color images of supernova, nebulae and planets. Sometimes the pictures were taken differently—through color filters or at multiple wavelengths—but for most of them, Berry relied on his trusty Photoshop to make them pop. Sometimes multiple images needed to be patched together or layered on top of one another to remove a cosmic glare and Berry did that, too. For Chandra, he also made animations of black holes and of the Chandra spacecraft itself, which are still used there today.

    By this time, these institutions employed entire teams of science visualizers. Kimberly Arcand, now Visualization Lead at Chandra, recalls working with Berry for an animation of Cassiopeia A, a supernova remnant.

    A false color image of Cassiopeia A (Cas A) using observations from both the Hubble and Spitzer telescopes as well as the Chandra X-ray Observatory (cropped).
    9 June 2005
    Author Oliver Krause (Steward Observatory) George H. Rieke (Steward Observatory) Stephan M. Birkmann (Max-Planck-Institut fur Astronomie) Emeric Le Floc’h (Steward Observatory) Karl D. Gordon (Steward Observatory) Eiichi Egami (Steward Observatory) John Bieging (Steward Observatory) John P. Hughes (Rutgers University) Erick Young (Steward Observatory) Joannah L. Hinz (Steward Observatory) Sascha P. Quanz (Max-Planck-Institut fur Astronomie) Dean C. Hines (Space Science Institute) Courtesy NASA/JPL-Caltech.

    “I definitely looked up to Dana as to what was possible in a career,” she says. Arcand is using the same decades-old data to make significantly more cutting-edge animations of Cassiopeia A in virtual reality.

    After Chandra, Berry landed a job as lead animator at Wilkinson Microwave Anisotropy Probe, which brought back images in microwaves and whose scientists won the 2018 Breakthrough Prize for their detailed maps of the early universe. Meanwhile, the Hubble images, now colored by Berry’s successor and visualization savant Zolt Levay and his team, started to look more and more like paintings. Pillars of Creation, a mélange of 32 different images taken in 1995 by four different Hubble cameras, used a similar technique similar to what Berry used on his first job: green for Hydrogen, red for ionized sulfur, blue for ionized oxygen.

    Pillars of Creation. in the Eagle Nebula, NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

    Eagle Nebula NASA/ESA Hubble Public Domain

    Pillars is now the most recognizable of all the Hubble images. And the technique of using art to communicate science had caught on: beyond still images, animation presented an opportunity for TV networks like Discovery, National Geographic and the Smithsonian to make more enthralling space documentaries, and Berry was interested in that direction as well. In the 2000s, Berry got a call from Steve Burns at Discovery Channel who was looking for someone to help produce the 25th-anniversary edition of Carl Sagan’s Cosmos, the iconic documentary he had admired as a kid.

    Berry was jazzed. “I had basically been asked to clean up the Mona Lisa,” he recalls.

    Berry combed through the film, cutting outdated bits and updating several animations. Ann Druyan argued that some animations should stay no matter what, like the line drawing of evolution through all of time. “Starting documentary work wasn’t the same cold splash that landing the job at Space Telescope was, but I felt pretty excited nevertheless,” he says. He finished the update in a mere 3 months.

    After Cosmos, Berry worked on an episode of The Universe series for The History Channel in 2008 and published the book Smithsonian Intimate Guide to the Cosmos in 2008. In the same year, he wrote and produced the documentary Hubble’s Amazing Universe for the TV show Naked Science, and in 2009 wrote and directed Alien Earths for National Geographic, which garnered an Emmy nomination.

    n 2014, Berry was asked to work on a few mini-segments for the new Cosmos: A Spacetime Odyssey with Neil DeGrasse Tyson. His role would be pre-visualization: thinking about how to illustrate DNA dividing, water evaporating, and other things happening on a molecular scale. Dozens of other science visualizers and graphics people worked on the documentary. When it was released, Cosmos: A Space-time Odyssey became the most watched series ever for National Geographic International.

    Today, there are frequently scientists who take issue with how science-minded films portray concepts like multi-dimensional worlds, time travel, and end-of-universe scenarios. But the value of using art for science outreach is indisputable. “Hubble set the bar, and established astronomy outreach as a really valid thing to do,” says Arcand. Another early colleague of Berry’s at The Space Telescope Science Institute, Ray Villard, now News Director there, agrees. “The success of the Hubble pictures is that they present the awe and wonder of the universe without scaring some people away with scientific terminology,” he says.

    Berry is thankful for witnessing the growth of science visualization as a beloved profession. “One of the legacies of Hubble was the fact that art was brought into the service of science,” he says. “There will never be another big science project that doesn’t benefit from visualization tools.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Smithsonian magazine and Smithsonian.com place a Smithsonian lens on the world, looking at the topics and subject matters researched, studied and exhibited by the Smithsonian Institution — science, history, art, popular culture and innovation — and chronicling them every day for our diverse readership.

  • richardmitnick 8:58 am on April 23, 2018 Permalink | Reply
    Tags: , , , Everything You Ever Wanted to Know About Earth’s Past Climates, , , Smithsonian.com   

    From Smithsonian.com: “Everything You Ever Wanted to Know About Earth’s Past Climates” 


    April 16, 2018
    Rachel E. Gross

    They have a lot to tell us about our future.


    In Silent Spring, Rachel Carson considers the Western sagebrush. “For here the natural landscape is eloquent of the interplay of forces that have created it,” she writes. “It is spread before us like the pages of an open book in which we can read why the land is what it is, and why we should preserve its integrity. But the pages lie unread.” She is lamenting the disappearance of a threatened landscape, but she may just as well be talking about markers of paleoclimate.

    To know where you’re going, you have to know where you’ve been. That’s particularly true for climate scientists, who need to understand the full range of the planet’s shifts in order to chart the course of our future. But without a time machine, how do they get this kind of data?

    Like Carson, they have to read the pages of the Earth. Fortunately, the Earth has kept diaries. Anything that puts down yearly layers—ocean corals, cave stalagmites, long-lived trees, tiny shelled sea creatures—faithfully records the conditions of the past. To go further, scientists dredge sediment cores and ice cores from the bottom of the ocean and the icy poles, which write their own memoirs in bursts of ash and dust and bubbles of long-trapped gas.

    In a sense, then, we do have time machines: Each of these proxies tells a slightly different story, which scientists can weave together to form a more complete understanding of Earth’s past.

    In March, the Smithsonian Institution’s National Museum of Natural History held a three-day Earth’s Temperature History Symposium that brought teachers, journalists, researchers and the public together to enhance their understanding of paleoclimate. During an evening lecture, Gavin Schmidt, climate modeler and director of NASA’s Goddard Institute for Space Studies, and Richard Alley, a world-famous geologist at Pennsylvania State University, explained how scientists use Earth’s past climates to improve the climate models we use to predict our future.

    Here is your guide to Earth’s climate pasts—not just what we know, but how we know it.

    How do we look into Earth’s past climate?

    It takes a little creativity to reconstruct Earth’s past incarnations. Fortunately, scientists know the main natural factors that shape climate. They include volcanic eruptions whose ash blocks the sun, changes in Earth’s orbit that shift sunlight to different latitudes, circulation of oceans and sea ice, the layout of the continents, the size of the ozone hole, blasts of cosmic rays, and deforestation. Of these, the most important are greenhouse gases that trap the sun’s heat, particularly carbon dioxide and methane.

    As Carson noted, Earth records these changes in its landscapes: in geologic layers, fossil trees, fossil shells, even crystallized rat pee—basically anything really old that gets preserved. Scientists can open up these diary pages and ask them what was going on at that time. Tree rings are particularly diligent record-keepers, recording rainfall in their annual rings; ice cores can keep exquisitely detailed accounts of seasonal conditions going back nearly a million years.

    Ice cores reveal annual layers of snowfall, volcanic ash and even remnants of long-dead civilizations. (NASA’s Goddard / Ludovic Brucker)

    What else can an ice core tell us?

    “Wow, there’s so much,” says Alley, who spent five field seasons coring ice from the Greenland ice sheet. Consider what an ice core actually is: a cross-section of layers of snowfall going back millennia.

    When snow blankets the ground, it contains small air spaces filled with atmospheric gases. At the poles, older layers become buried and compressed into ice, turning these spaces into bubbles of past air, as researchers Caitlin Keating-Bitonti and Lucy Chang write in Smithsonian.com. Scientists use the chemical composition of the ice itself (the ratio of the heavy and light isotopes of oxygen in H2O) to estimate temperature. In Greenland and Antarctica, scientists like Alley extract inconceivably long ice cores—some more than two miles long!

    Ice cores tell us how much snow fell during a particular year. But they also reveal dust, sea salt, ash from faraway volcanic explosions, even the pollution left by Roman plumbing. “If it’s in the air it’s in the ice,” says Alley. In the best cases, we can date ice cores to their exact season and year, counting up their annual layers like tree rings. And ice cores preserve these exquisite details going back hundreds of thousands of years, making them what Alley calls “the gold standard” of paleoclimate proxies.

    Wait, but isn’t Earth’s history much longer than that?

    Yes, that’s right. Paleoclimate scientists need to go back millions of years—and for that we need things even older than ice cores. Fortunately, life has a long record. The fossil record of complex life reaches back to somewhere around 600 million years. That means we have definite proxies for changes in climate going back approximately that far. One of the most important is the teeth of conodonts—extinct, eel-like creatures—which go back 520 million years.

    But some of the most common climate proxies at this timescale are even more miniscule. Foraminifera (known as “forams”) and diatoms are unicellular beings that tend to live on the ocean seafloor, and are often no bigger than the period at the end of this sentence. Because they are scattered all across the Earth and have been around since the Jurassic, they’ve left a robust fossil record for scientists to probe past temperatures. Using oxygen isotopes in their shells, we can reconstruct ocean temperatures going back more than 100 million years ago.

    “In every outthrust headland, in every curving beach, in every grain of sand there is a story of the earth,” Carson once wrote. Those stories, it turns out, are also hiding in the waters that created those beaches, and in creatures smaller than a grain of sand.

    Foraminifera. (Ernst Haeckel)

    How much certainty do we have for deep past?

    For paleoclimate scientists, life is crucial: if you have indicators of life on Earth, you can interpret temperature based on the distribution of organisms.

    But when we’ve gone back so far that there are no longer even any conodont teeth, we’ve lost our main indicator. Past that we have to rely on the distribution of sediments, and markers of past glaciers, which we can extrapolate out to roughly indicate climate patterns. So the further back we go, the fewer proxies we have, and the less granular our understanding becomes. “It just gets foggier and foggier,” says Brian Huber, a Smithsonian paleobiologist who helped organize the symposium along with fellow paleobiologist research scientist and curator Scott Wing.

    How does paleoclimate show us the importance of greenhouse gases?

    Greenhouse gases, as their name suggests, work by trapping heat. Essentially, they end up forming an insulating blanket for the Earth. (You can get more into the basic chemistry here.) If you look at a graph of past Ice Ages, you can see that CO2 levels and Ice Ages (or global temperature) align. More CO2 equals warmer temperatures and less ice, and vice versa. “And we do know the direction of causation here,” Alley notes. “It is primarily from CO2 to (less) ice. Not the other way around.”

    We can also look back at specific snapshots in time to see how Earth responds to past CO2 spikes. For instance, in a period of extreme warming during Earth’s Cenozoic era about 55.9 million years ago, enough carbon was released to about double the amount of CO2 in the atmosphere. The consequentially hot conditions wreaked havoc, causing massive migrations and extinctions; pretty much everything that lived either moved or went extinct. Plants wilted. Oceans acidified and heated up to the temperature of bathtubs.

    Unfortunately, this might be a harbinger for where we’re going. “This is what’s scary to climate modelers,” says Huber. “At the rate we’re going, we’re kind of winding back time to these periods of extreme warmth.” That’s why understanding carbon dioxide’s role in past climate change helps us forecast future climate change.

    That sounds pretty bad.


    I’m really impressed by how much paleoclimate data we have. But how does a climate model work?

    Great question! In science, you can’t make a model unless you understand the basic principles underlying the system. So the mere fact that we’re able to make good models means that we understand how this all works. A model is essentially a simplified version of reality, based on what we know about the laws of physics and chemistry. Engineers use mathematical models to build structures that millions of people rely on, from airplanes to bridges.

    Our models are based on a framework of data, much of which comes from the paleoclimate proxies scientists have collected from every corner of the world. That’s why it’s so important for data and models to be in conversation with each other. Scientists test their predictions on data from the distant past, and try to fix any discrepancies that arise. “We can go back in time and evaluate and validate the results of these models to make better predictions for what’s going to happen in the future,” says Schmidt.

    Here’s a model:


    It’s pretty. I hear the models aren’t very accurate, though.

    By their very nature, models are always wrong. Think of them as an approximation, our best guess.

    But ask yourself: do these guesses give us more information than we had previously? Do they provide useful predictions we wouldn’t otherwise have? Do they allow us to ask new, better questions? “As we put all of these bits together we end up with something that looks very much like the planet,” says Schmidt. “We know it’s incomplete. We know there are things that we haven’t included, we know that we’ve put in things that are a little bit wrong. But the basic patterns we see in these models are recognizable … as the patterns that we see in satellites all the time.”

    So we should trust them to predict the future?

    The models faithfully reproduce the patters we see in Earth’s past, present—and in some cases, future. We are now at the point where we can compare early climate models—those of the late 1980s and 1990s that Schmidt’s team at NASA worked on—to reality. “When I was a student, the early models told us how it would warm,” says Alley. “That is happening. The models are successfully predictive as well as explanatory: they work.” Depending on where you stand, that might make you say “Oh goody! We were right!” or “Oh no! We were right.”

    To check models’ accuracy, researchers go right back to the paleoclimate data that Alley and others have collected. They run models into the distant past, and compare them to the data that they actually have.

    “If we can reproduce ancient past climates where we know what happened, that tells us that those models are a really good tool for us to know what’s going to happen in the future,” says Linda Ivany, a paleoclimate scientist at Syracuse University. Ivany’s research proxies are ancient clams, whose shells record not only yearly conditions but individual winters and summers going back 300 million years—making them a valuable way to check models. “The better the models get at recovering the past,” she says, “the better they’re going to be at predicting the future.”

    Paleoclimate shows us that Earth’s climate has changed dramatically. Doesn’t that mean that, in a relative sense, today’s changes aren’t a big deal?

    When Richard Alley tries to explain the gravity of manmade climate change, he often invokes a particular annual phenomenon: the wildfires that blaze in the hills of Los Angeles every year. These fires are predictable, cyclical, natural. But it’d be crazy to say that, since fires are the norm, it’s fine to let arsonists set fires too. Similarly, the fact that climate has changed over millions of years doesn’t mean that manmade greenhouse gases aren’t a serious global threat.

    “Our civilization is predicated on stable climate and sea level,” says Wing, “and everything we know from the past says that when you put a lot of carbon in the atmosphere, climate and sea level change radically.”

    Since the Industrial Revolution, human activities have helped warm the globe 2 degrees F, one-quarter of what Schmidt deems an “Ice Age Unit”—the temperature change that the Earth goes through between an Ice Age and a non-Ice Age. Today’s models predict another 2 to 6 degrees Celsius of warming by 2100—at least 20 times faster than past bouts of warming over the past 2 million years.

    From NASA Earth Observatory

    How is Today’s Warming Different from the Past?

    Earth has experienced climate change in the past without help from humanity. We know about past climates because of evidence left in tree rings, layers of ice in glaciers, ocean sediments, coral reefs, and layers of sedimentary rocks. For example, bubbles of air in glacial ice trap tiny samples of Earth’s atmosphere, giving scientists a history of greenhouse gases that stretches back more than 800,000 years. The chemical make-up of the ice provides clues to the average global temperature.

    See the Earth Observatory’s series Paleoclimatology for details about how scientists study past climates.

    Glacial ice and air bubbles trapped in it (top) preserve an 800,000-year record of temperature & carbon dioxide. Earth has cycled between ice ages (low points, large negative anomalies) and warm interglacials (peaks). (Photograph courtesy National Snow & Ice Data Center. NASA graph by Robert Simmon, based on data from Jouzel et al., 2007.)

    Using this ancient evidence, scientists have built a record of Earth’s past climates, or “paleoclimates.” The paleoclimate record combined with global models shows past ice ages as well as periods even warmer than today. But the paleoclimate record also reveals that the current climatic warming is occurring much more rapidly than past warming events.

    As the Earth moved out of ice ages over the past million years, the global temperature rose a total of 4 to 7 degrees Celsius over about 5,000 years. In the past century alone, the temperature has climbed 0.7 degrees Celsius, roughly ten times faster than the average rate of ice-age-recovery warming.

    Temperature histories from paleoclimate data (green line) compared to the history based on modern instruments (blue line) suggest that global temperature is warmer now than it has been in the past 1,000 years, and possibly longer. (Graph adapted from Mann et al., 2008.)

    Models predict that Earth will warm between 2 and 6 degrees Celsius in the next century. When global warming has happened at various times in the past two million years, it has taken the planet about 5,000 years to warm 5 degrees. The predicted rate of warming for the next century is at least 20 times faster. This rate of change is extremely unusual.

    See the full NASA Earth Observatory article here .

    Of course there are uncertainties: “We could have a debate about whether we’re being a little too optimistic or not,” says Alley. “But not much debate about whether we’re being too scary or not.” Considering how right we were before, we should ignore history at our own peril.


    See the full article here .

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  • richardmitnick 12:56 pm on January 20, 2018 Permalink | Reply
    Tags: , , Geology Makes the Mayon Volcano Visually Spectacular—And Dangerously Explosive, Smithsonian.com, Strombolian eruptions,   

    From smithsonian.com: “Geology Makes the Mayon Volcano Visually Spectacular—And Dangerously Explosive” 


    January 19, 2018
    Maya Wei-Haas

    What’s going on inside one of the Philippines’ most active volcanoes?

    Lava cascades down the slopes of the erupting Mayon volcano in January 2018. Seen from Busay Village in Albay province, 210 miles southeast of Manila, Philippines. (AP Photo/Dan Amaranto)

    Last weekend, the Philippines’ most active—and attractive—volcano, Mount Mayon, roared back to life. The 8,070-foot volcano began releasing spurts of incandescent molten rock and spewing clouds of smoke and ash into the sky, causing over 30,000 local residents to evacuate the region. By the morning of January 18, the gooey streams of lava had traveled almost two miles from the summit.

    Though the images of Mount Mayon are startling, the volcano isn’t truly explosive—yet. The Philippine Institute of Volcanology and Seismology (PHIVolcs), which monitors the numerous volcanoes of the island chain, has set the current warning level at a 3 out of 5, which means that there is ”relatively high unrest.” At this point, explosive eruption is not imminent, says Janine Krippner, a volcanologist and postdoctoral researcher researcher at Concord University. If the trend continues, however, an eruption is possible in the next few weeks.

    Located on the large island of Luzon, Mount Mayon is known for its dramatically sloped edges and picturesque symmetry, which makes it a popular tourist attraction; some climbers even attempt to the venture to its smouldering rim. “It’s gorgeous, isn’t it?” marvels Krippner. But that beauty isn’t entirely innocuous. In fact, Krippner explains, the structure’s symmetrical form is partly due to the frequency of the volcano’s eruptions.

    “Mayon is one of the most active volcanoes—if not the most active volcano—in the Philippines, so it has the chance to keep building its profile up without eroding away,” she says. Since its first recorded eruption in 1616, there have been roughly 58 known events—four in just the last decade—which have ranged from small sputters to full-on disasters. Its most explosive eruption took place in 1814, when columns of ash rose miles high, devastated nearby towns and killed 1200 people.

    Many of these eruptions are strombolian, which means the cone emits a stuttering spray of molten rock that collects around its upper rim. (Strombolian eruptions are among the less-explosive types of blasts, but Mayon is capable of much more violent eruptions as well.) Over time, these volcanic rocks “stack up, and up, and up,” says Krippner, creating extremely steep slope. That’s why, near the top of the volcano, its sides veer at angles up to 40 degrees—roughly twice the angle of the famous Baldwin street in New Zealand, one of the steepest roads in the world.

    So why, exactly, does Mayon have so many fiery fits? It’s all about location.

    The islands of the Philippines are situated along the Ring of Fire, a curving chain of volcanism that hugs the boundary of the Pacific Ocean and contains three-fourths of all the world’s volcanoes. What drives this region of fiery activity are slow-motion collisions between the shifting blocks of Earth’s crust, or tectonic plates, which have been taking place over millions of years. The situation in the Philippines is in particularly complex, explains Ben Andrews, director of Smithsonian’s Global Volcanism Program. “It’s a place where we have a whole bunch of different subduction zones of different ages that are sort of piling together and crashing together,” he says. “It gets pretty hairy.”

    As one plate thrusts beneath another, the rocks begin to melt, fueling the volcanic eruption above. Depending on the composition of the melting rock, the lava can be thin and runny, or thick and viscous. This viscosity paired with the speed at which the magma rises determines the volcano’s explosivity, says Andrews: The thicker and quicker the lava, the more explosive the blast. Mayon produces magma of intermediate composition and viscosity, but it differs from eruption to eruption.

    Think of a volcanic eruption like opening a shaken bottle of soda, says Andrews. If you pop off the cap immediately, you’re in for a spray of sugary carbonated liquid to the face, just like the sudden release of gas and molten rock that builds under a plug of viscous magma. But if you slow down and let a little air out first—like the gases that can escape from liquid-y magma—a violent explosion is less likely.

    News outlets have been reporting on an “imminent explosion,” warning that Mayon will erupt within days. But given its activity so far, it’s not yet clear if, or when, Mayon will erupt. Volcanoes are extremely hard to predict as the magma is constantly changing, says Krippner.

    Since the volcano began belching, small pyroclastic flows—avalanches of hot rocks, ash and gas—have also tumbled down its flanks. Though dangerous, these pyroclastic flows have the potential to be much more devastating. Previously at Mayon, says Krippner, these flows have been clocked in at over 60 meters per second. “They’re extremely fast and they’re extremely hot,” she says. “They destroy pretty much everything in their path.”

    If the eruption continues, one of the biggest dangers is an explosive blast, which could produce a column of volcanic ash miles high. The collapse of this column can send massive, deadly pyroclastic flows racing down the volcano’s flanks. The last time Mayon burst in an explosive eruption was in 2001. With a roar like a jet plane, the volcano shot clouds of ash and molten rock just over six miles into the sky.

    Also of concern is the potential for what are known as lahars, or flows of debris. The volcanic rumblings have been actively producing volcanic ash, a material that’s more like sand than the kind of ash you see when you burn wood or paper, notes Krippner. A strong rain—as is frequent on these tropical islands—is all that’s needed to turn these layers of debris into a slurry and send it careening down the volcano’s slopes, sweeping with it anything that gets in its way. Mayon’s steep sides make it particularly susceptible to these mudflows.

    Residents suffered the full potential for destruction of Mayon’s lahars in November of 2006 when a typhoon swept the region, bringing with it heavy rain that saturated built up material. A massive lahar formed, destroying nearby towns and killing 1,266 people.

    Both Krippner and Andrews stress that local residents are in good hands under PHIVolcs’ careful watch. The researchers have installed a complex network of sensors that monitor Mayon’s every tremble and burp and are using their vast amounts of knowledge garnered from past events to interpret the volcano’s every shiver.

    And as Krippner notes, “it’s still got two more levels to go.” If PHIVoics raises the alert level to a 4 or 5, she says, “that could mean something bigger is coming.”

    See the full article here .

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  • richardmitnick 6:45 pm on November 27, 2017 Permalink | Reply
    Tags: Smithsonian.com, Stratovolcano, The Geology of Bali’s Simmering Agung Volcano,   

    From smithsonian.com: “The Geology of Bali’s Simmering Agung Volcano” 


    Jason Daley

    The high viscosity magma of stratovolcanoes like Agung makes them extremely explosive—and potentially deadly.

    Mount Agung (MAGMA Indonesia)

    Bali authorities have issued evacuation orders for 100,000 people living within a six-mile radius of volcanic Mount Agung, the highest point on the Indonesian island.

    Trouble has been brewing at the volcano for quite some time. Researchers recorded seismic activity at Agung beginning in August, with the unrest increasing in the following weeks, according to the Earth Observatory of Singapore. On September 22, authorities raised to the volcano’s status to level 4, its highest warning category. Then, last Tuesday the volcano began emitting plumes of smoke and mudflows streamed through local waterways. Over the weekend, the ash cloud reached 30,000 feet and magmatic eruptions began, reports the Associated Press. About 59,000 travelers are currently stuck on the island after the ash caused the international airport to close.

    While authorities tell the AP they don’t expect a major eruption, the activity changed early this morning from emission of steam to magma. So officials are playing it safe. Last time Agung erupted in 1963, an estimated 1,100 people died. And since the 1963 catastrophe, population density has only intensified on Agung’s slopes.

    So what makes Agung so dangerous? Blame its geology.

    Agung is what’s known as a stratovolcano. Also known as composite volcanoes, these formations occur at tectonic subduction zones, areas where two tectonic plates meet and one plate slides underneath another, geophysicist Jacqueline Salzer at the German Research Centre for Geosciences tells Fabian Schmidt at Deutsche Welle.

    The tectonic plates of the world were mapped in 1996, USGS.

    The lava in those areas is usually thick and sticky, causing pressures to build within the steep cones, which results in highly explosive—and deadly—eruptions.

    As Janine Krippner, a volcanologist at the University of Pittsburgh, writes for the BBC, Agung has gone through the predictable stages of a waking volcano. In August, small earthquakes were measured, but the mountain appeared unchanged. Then, in September, as rising magma heated the interior of the cone, plumes of steam were observed as the water in the mountain heated up.

    Beginning last week, steam-driven or phreatic eruptions began. During this time, steam inside the volcano built up pressure causing small explosions to shoot ash, crystals and rock into the air. Now the magma has reached the surface—the point at which it is called lava—and its glow can be seen at the top of the mountain.

    Authorities are hopeful the eruption won’t continue further but if it does, several types of disasters could unfold. The cloud of gas and steam will blow off larger pieces of the mountain off, shooting rock “bombs” into the air. Actual lava flows could also stream down the mountain for several miles. But the most dangerous element of the eruption is the pyroclastic flow, an explosion of hot gas and debris that follows valleys or low-lying areas. These flows can race down the mountain at 50 miles per hour, destroying everything in its path.

    Another major concern is lahars which occur when volcanic debris and ash mixes with water, creating a slurry the consistency of wet concrete. Lahars can rush down slopes at up to 120 miles per hour and swell in volume, destroying any villages or structures in its path.

    According to John Seach at VolcanoLive, during the 1963 Agung eruption, 820 people were killed by pyroclastic flows, 163 died from falling ash and rock and 165 were killed by lahars.

    The 1963 eruption also had global consequences. Alle McMahon at the Australia Broadcasting Corporation reports that the sulphur dioxide blown into the atmosphere by that event temporarily cooled the Earth by 0.1-0.4 degrees Celsius by reflecting some of the sun’s ultraviolet radiation.

    If Agung does have another major eruption, this miniscule amount of cooling is likely too small to be noticed. But the immediate consequences of such an eruption can be deadly, so authorities are encouraging locals to heed the evacuation notices.

    See the full article here .

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  • richardmitnick 1:37 pm on May 22, 2017 Permalink | Reply
    Tags: , , How Thousand-Year-Old Trees Became the New Ivory, Smithsonian.com   

    From Smithsonian: “How Thousand-Year-Old Trees Became the New Ivory” 


    Lyndsie Bourgon

    Ancient trees are disappearing from protected national forests around the world. A look inside $100 billion market for stolen wood.

    Torrance Coste of the Wilderness Committee illustrates the immensity of the missing Carmanah cedar in 2012. (Courtesy Torrance Coste)

    I. The Case of the Missing Cedar

    It was a local hiker who noticed, during a backwoods stroll in May 2012, the remains of the body. The victim in question: an 800-year-old cedar tree. Fifty meters tall and with a trunk three meters in circumference, the cedar was one of the crown jewels in Canada’s Carmanah Walbran Provincial Park. Now all that remained was a minivan-sized section of its trunk, surrounded by shards of wood and dust, with broken heavy equipment chains lying nearby.

    This park is firmly rooted, filled with centuries old Sitka spruce and cedar that impose a towering permanence. These trees are also an integral part of the forest ecosystem: moss and lichen grow on them, mushrooms sprout from the damp bark at their base. Their branches are home to endangered birds like the tiny grey and white marbled murrelet, which scientists presumed regionally extinct until they found a lone bird in the Carmanah.

    But lately, these living ecosystems have been disappearing across the province. In the past decade, forest investigators have found themselves fielding cases in which more than 100 trees were stolen at once.

    The Carmanah hiker, Colin Hepburn, happened to be a member of the activist group Wilderness Committee. He called Torrance Coste, the protection group’s regional campaigner, who alerted British Columbia Parks and the Royal Canadian Mounted Police (RCMP). A week later, Coste travelled from Victoria to the Carmanah. Coming upon the old growth’s stump was “overwhelming,” he says. He demonstrated its immense size by lying down on it, sitting on it and standing on it in news photos.

    The province took the case seriously. The theft was jointly investigated by BC Parks, the RCMP and the province’s Conservation Officer Service, but with no promising leads, the RCMP dropped the case within a few months. BC Parks keeps the file open; Don Closson, the area’s supervisor, says they are waiting to breathe new life into it. But if history is any indication, that isn’t likely to happen: When it comes to the underground world of black market timber, the case of this 800-year-old cedar is just the tip of the iceberg.

    Global timber theft has grown into a “rapidly escalating environmental crime wave” according to a 2012 report by the United Nations Environmental Program (UNEP) and Interpol, titled Green Carbon, Black Trade. The report estimates that somewhere between 15 to 30 per cent of the global timber trade is conducted through the black market and linked to organized crime outfits that wouldn’t balk at trading weapons or humans. Now with armed “timber cartels” as part of their operation, these groups have identified profit in the immense value of ancient nature.

    Every summer, Interpol and the UNEP hold a conference in Nairobi where they convene over issues in international poaching and black market trade. In the past couple of years, the conference has been focused on elephant poaching and timber theft. Wood, says the UNEP, is the new ivory: a natural resource valued for its scarcity and beauty, which takes decades to grow but just moments to destroy.

    “Our parks are comparable to cathedrals or castles in Europe,” says Coste. “But they are not protected. There is no security.”

    Globally, poached trees are estimated to be worth somewhere between $30 and $100 billion. The U.S. claims about $1 billion of that in its borders. But it’s impossible to truly measure what all that stolen wood is worth.

    That’s because the worth of timber is generally only considered in market value—how much you can sell it for in the form of boards or shake blocks—says Matthew Diggs, an attorney in Seattle who has dealt with many timber theft cases. That number doesn’t take into account the fact that, in parks like Washington state’s Olympic National Forest, there are natural ecosystems that can only exist in an untouched environment.

    “Honestly, there is really no way to put a value on that,” says Diggs. “[It robs] our region of one of its most precious resources—trees which will take centuries to return.”

    Cedar boardwalk through valley bottom with a (naturally) fallen tree, Carmanah Valley, Vancouver Island, British Columbia, Canada. (Chris Cheadle / Alamy)

    II. The Perfect Crime

    Two main factors have made timber so appealing in recent years. First, the pay-off: One massive old growth cedar can fetch close to $20,000. A report released in 2000 from the Canadian Forest Service’s Pacific Forestry Centre noted theft of Canada’s timber as a growing problem, costing B.C. $20 million annually. Red cedar is especially at risk, with thieves often specifically targeting its ‘high grade’ old growth. Even smaller parts of trees can be incredibly valuable: In 2014 there were 18 cases of thieves hacking out chunks of burl from 1000-year-old California redwoods.

    Second, stealing trees is low-risk. In a globalized economy, timber is exceptionally easy for thieves to get their hands on, says Cameron Kamiya, Canada’s only full-time forest crime investigator. And the Carmanah is the perfect place to commit a crime: a remote rainforest sanctuary on the Canadian west coast, thick with damp air and spearmint canopies of moss. It is so vast and so sparingly visited that park wardens only patrol the area about four times a year.

    Kamiya runs a two-person outpost for the whole of British Columbia. In his first case on the job, he charged two men with the theft of broadleaf maple trees from the small town of Abbotsford, which they had been poaching and selling to guitar manufacturers. “Maple is an ongoing problem,” he says. “It isn’t your standard kind of tall, straight tree. It branches off and forks and they lean and tilt, but if you know what you’re doing and you have someone to buy it, it’s quite lucrative.”

    That rare successful case illustrates a common theme in timber theft: When thieves are caught, it’s almost entirely thanks to luck. In this case, a group of mountain bikers were forging a path through the woods when they came across three people with a chainsaw and a tree at their feet. The bikers had a GoPro video camera on them, which they used to record the faces of the thieves. Then, they reported the interaction to the Forestry Department, who called Kamiya. Together, Kamiya and Forestry decided to take a hike to the area where the meeting happened.

    As they were walking, they heard a tree fall.

    The pair snuck up to the top where they found two people they recognized from the video, and who eventually took them to a spot with two others that was dotted with gear: an axe, some jackets, rope. One of the people was covered in dust and was wearing gumboots, making the group’s excuse—“We’re on a hike!”—seem unlikely. A chainsaw was buried amongst some ferns nearby. “They did a really lousy job of it,” says Kamiya. “I don’t know why they bothered.”

    Kamiya and the Forestry Department took their culprits down to the main road, but the location was remote and they didn’t have enough room to transport them all back to the station. The group agreed to provide a statement later and, “of course afterwards they all recanted,” Kamiya recalls. In the end only one was charged with the theft. He was given a conditional discharge, six months’ probation and was ordered to pay a $500 fine.

    In this field, even charging one thief is unusual, says Kamiya. “It was coincidence and luck,” he says. “It’s like a needle in a haystack when you’re walking around looking for one tree out of a pile.”

    Wildlife biologist Terry Hines stands next to a scar where poachers hacked a large burl from an old growth redwood tree in the Redwood National and State Parks near Klamath, CA, in 2013. (National Parks Service / Redwood National and State Parks / Laura Denn)

    III. Wood Without a Name

    On paper, a number of government groups are hard at work to reduce illegal logging. The problem is, none of them are equipped to effectively combat a global trade of this magnitude—let alone an organized crime network.

    There are the Forest Stewardship Council (FSC) and its European contemporary, the EU Forest Law Enforcement, Governance and Trade Voluntary Partnership Agreements. But these groups are just what the names suggest: That is, voluntary agreement systems for countries and companies to participate in if they choose. Plus, they’re mostly focused on generating incentives for legal trade.

    CITES, a convention that many countries follow, regulates the trade of plants and animals, including about 600 timber species. About 400 of these species—including rosewood, bigleaf mahogany and Asian yews—are actively, commercially exploited. In theory, countries that participate in CITES agree to subject exporters to trade regulations, including requiring that they show a permit for the wood they are trading.

    But Chen Hin Keong, head of the Global Forest Trade Programme at the wildlife trade monitoring organization TRAFFIC International, says that permits often aren’t requested. “There is a good chance that they won’t ask. No one bothers,” says Keong. “If I’m a retailer selling furniture, I can ask my supplier if it’s legal, but he might buy the materials from 10 different sources and he’ll have to check. He might buy his plywood from one place, his dowels from another, planks from somewhere else.”

    The hands that a felled log passes through have been greased by the ease of globalized trade. The sheer volume of wood threaded through the world’s largest ports makes it easy to move a single container full of poached wood, or a container full of wood that was both legally and illegally logged. “If you deal drugs or kill an elephant, you are constantly at risk,” says Christian Nellemann, head of rapid response assessments at UNEP. “If you deal with timber, nobody really cares.”

    Most timber travels first to busy ports in Malaysia and China, where it is manufactured into finished product before heading to North America and Europe. The pace at these ports is harried. “If you deal with natural resources you generally deal with large volumes of relatively low-value laundered goods. It breaks with the traditional mindset of smuggling,” Nellemann explains. “It would be like trying to check all the fruit and toothpaste in supermarkets.”

    Keong likens a piece of furniture to a cell phone—minerals are extracted from one place, everything cobbled together piecemeal in another. Often, when an inspecting officer opens a container of cargo, he or she is sorting through legally sourced items to find the illegal material buried in the middle or hidden underneath. But even if they suspect the wood within may be illegally traded, how are they to know the species of a tree by looking at a piece of plywood?

    Right now, the answer is that there’s no way to know for sure. That’s why, in a case like the Carmanah cedar, investigations rarely make it further than the discovery of a stump. After all, a tree’s vanished body is both the victim and the evidence. Even if someone is pulled over with suspicious wood in the back of a truck, the challenge then becomes linking that wood with the tree it once was.

    To create a body of proof from the shards left behind, they must be matched to the exact stump it came from. “You have to use other ways,” says John Scanlon, the secretary general of CITES. “You have to look more closely at the texture of the timber. Or sometimes you need forensics.”

    Coast Redwoods in Stout Grove, Jedediah Smith Redwoods State Park, California. (Radius Images / Alamy )

    IV. Fingerprinting the Forest

    As global tree researchers get more savvy, they’re figuring out how to fingerprint wood products back to the ancient trees they came from.

    Eleanor White, a retired molecular biologist with the Canadian Forest Services, was the first to develop a way to “fingerprint” trees. In the late 1990s, she developed a method that has since played a key role in advancing a database of red and yellow cedar DNA in British Columbia. White’s method uses a mixture of solvents to isolate short, repeated DNA segments “microsatellites” from samples of wood. Like fingerprints, each tree has a unique pattern of these microsatellites.

    Tree fingerprints are just one promising innovation in a relatively new field: forest forensics. New scientific developments are being used to raise the stakes of this kind of lucrative, difficult-to-trace theft. The goal is to dissuade both individual poachers—those who take trees for firewood, or harvest a Christmas tree from preserved land—and large-scale timber thieves alike.

    In Oregon, U.S. Fish and Wildlife has developed its own forensics lab to investigate cases of poaching and timber theft. Ken Goddard, the lab’s director, has been working in park crime since 1979. He wrote a manual for environmental crime scene investigation and is also a bestselling serial novelist, having written books like Double Blind, which follows a U.S. Fish & Wildlife special agent into the wilderness.

    Today he runs the only lab in the world dedicated to crimes against wildlife—“though we sure don’t want to be,” he says. They tackle some of the most bizarre crimes in America: illegally imported caviar, poached bear gall bladder, plants coated in banned pesticides, and of course, tree poaching.

    “When we first started looking at it”—tree theft—“we were stunned,” says Goddard. “We were starting to hear stories from agents in other countries, about entire forests being clear-cut and ships filled with raw trees in containerized cargo. At that point we couldn’t make an identification if it was milled into planks, so we had to come up with something.” Right now they spend a lot of time handling the illegal import of agarwood, which most often makes its way to the lab in the form of wood chips or incense sticks. Known for its dark, aromatic resin that provides the musky, earthy smell common in manufactured scents, a kilo of agarwood can sell for up to $100,000.

    The lab guides investigators who intercept these shipments on how to get samples. It isn’t exactly glamorous. The work includes digging through shipping containers filled with raw material and extracting single logs or planks to take back to the lab. “It’s pretty horrendous work, the mechanics and science of it,” says Goddard. “You’re supposed to take a random sampling for results, but imagine a container full of 2x4s and you’re supposed to take the 412th 2×4 in the bunch. It’s a tremendous amount of physical work, to get that sample.”

    Very little of the work that the lab’s criminologists, Ed Espinoza and Gabriela Chavarria, do is actually based in the forest. Rather, they most often examine evidence that has already been manipulated; that is, the tree has already been turned into a product. The team will receive boxes of wood chips or shipments of milled, kiln-dried planks from Fish & Wildlife agents or border inspectors, and get to work hunting around for specific ions to determine the species of wood.

    They use chemistry to nab tree poachers after the act, because by the time the samples get to them, the wood is almost unrecognizable. On rare occasions, they have been asked to study full logs or planks that have been misleadingly labeled or declared. “With all the shows today, they mix up CSI with forensics and it really isn’t,” says Espinoza.

    Espinoza has done groundbreaking work when it comes to developing a method to identify tree genuses: “Up until a few months ago, as far as anyone in the world could go was family,” says Goddard. Espinoza’s work has since been applied to a species of trees called aguilaria, in which agarwood falls. “It’s a mind-boggling discovery,” says Goddard.

    Espinoza uses mass spectrometry to identify chemical compounds, essentially by turning an unknown liquid (in this case, oils from bark) into a gas and then injecting it into the dart instrument. The chemical compounds then show up on a screen a few seconds later.

    An ancient cedar tree like this one can grow for nearly hundreds of years, but be felled in less than a week. (Courtesy Torrance Coste)

    In addition to forensics, there have been some attempts by non-governmental organizations to push for a customer-driven solution. The World Wildlife Foundation is working with companies like Kimberly Clarke, Hewlett-Packard and McDonald’s to help identify places in their supply chain where they may be inadvertently part of the world’s illegal timber trade. McDonald’s, for instance, is focusing entirely on the origins of its paper packaging.

    “We can offer real time information to these companies, about sourcing from a certain area,” says Amy Smith, a manager for wood products at the WWF. “We want to keep traceability visible.” But they are also not a regulating body. They essentially provide a service and country profiles, for interested clients.

    Yet if there is no political will, Keong fears consumer activism. “People are poor,” he says. “If consumers are put off buying timber then you might affect a lot of livelihoods in other countries. It’s not a simple solution.” Nellemann believes in the power of halting criminal networks is through pressing tax fraud charges. “This is about security, but it’s also about governments losing vast amounts of revenues that leave the country with illegal logging,” he says.

    Scanlon agrees: “We need to up the ante here.”

    When the poet Seamus Heaney was perched at his mother’s deathbed, he wrote in “Clearances”: “The space we stood around had been emptied/ Into us to keep, it penetrated/ Clearances that suddenly stood open/ High cries were felled and a pure change happened.” “I was thinking of when a tree is cut,” he said, in a later interview. “For a moment it’s as if the air is shaken and there is new space in the world. An emptiness.”

    Trees are not immortal. They live and die, with the average cedar tree in Canada reaching 800 years or so before cracking, disintegrating and falling down of their own accord. Today, in a ring surrounding the base of the cedar stump in the Carmanah, saplings have begun to sprout. If the earth is lucky, a missing tree will leave a clearing in the canopy, a window into sky and sun, a funnel with enough room for a new tree to grow in its place.

    The cedar in the Carmanah was near the end of its life. But tree theft investigators want to ensure that none of these ancient giants meetings a similar fate before its time. Their goal is to make the risks for poaching these trees before their time too high—to treat the theft of plant life like you might the trade of drugs or arms. It’s also to make the act of corruption within government and private business so difficult to pull off that customs agents can do their jobs. The goal can seem impossible.

    “I’ve been working on this for awhile now and I still do not…” Keong sighs. “Sometimes I think we are not there yet. We are only in early days. The political will that we are all in this one world … we are not there yet.”

    See the full article here .

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  • richardmitnick 8:12 pm on October 18, 2016 Permalink | Reply
    Tags: , Did a Comet Set Off Global Warming 56 Million Years Ago?, Smithsonian.com   

    From Smithsonian: “Did a Comet Set Off Global Warming 56 Million Years Ago?” 


    October 18, 2016
    Jason Daley

    (Puchan via iStock)

    About 55.6 million years ago, during the Paleocene-Eocene Thermal Maximum (PETM), global warming sped out of control. As the atmosphere’s carbon levels rose, so did sea levels and temperatures, which jumped by 46.4 degrees Fahrenheit. Many species either struck out on massive migrations or went extinct

    Though this period is one of the best geologic representations of what climate change is doing to the planet today, researchers still don’t know why it happened, reports Sarah Kaplan for The Washington Post. Some argue that the rise in carbon took place over 5,000 to 20,000 years and could have come from volcanic activity. Others believe a change in Earth’s orbit or a change in ocean currents could have triggered the upward march of temperatures.

    In 2003 researcher Dennis Kent of Columbia University suggested that a comet impact could have triggered such a rapid warming event. Now, he and his colleagues present potential evidence that a comet did indeed set off the PETM.

    In a new paper published in Science, Kent suggests that tiny glass spheres called microtektites found along the coast of New Jersey are signs that a comet hit earth around the time of the Thermal Maximum. Microtektites are thought to form from massive extraterrestrial impacts with Earth, which spray the beads of rapidly cooling molten glass and quartz out from the impact zones.

    Morgan Schaller, lead author of the study and researcher at Rensselaer Polytechnic Institute, found the sand-grain sized glass beads in core samples collected in suburban Millville and Wilson Lake, New Jersey, in a stream bed in the town of Medford and in a core taken from the deep sea bed near Bermuda. Each of them contain the dark beads in the layer associated with the start of the PETM.

    Schaller wasn’t originally on the hunt for evidence of a comet strike at all, reports Paul Voosen at Science. Instead, he and graduate student Megan Fung were hunting the Jersey shore for fossils of microorganisms called foraminifera, which can be used to date sediments, when they encountered the microtektites.

    The team concluded that the spheres came from an extraterrestrial impact, and a layer of charcoal above and below the stratum containing the beads indicates a time of immense wildfires, which would have occurred after a comet hit. Schaller believes the amount of carbon introduced by the comet would have been immense.

    “It’s got to be more than coincidental that there’s an impact right at the same time [of the PETM],” Schaller says in the press release. “If the impact was related, it suggests the carbon release was fast.”

    Not everyone is convinced by the evidence. Ellen Thomas, a geologist at Wesleyan University in Middletown, Connecticut, tells Voosen she has re-examined cores taken at the PETM boundary in New Jersey and globally and has found no spherules. If the researchers are able to definitively date the beads, she says she’ll be convinced. Otherwise she believes the microtektites may come from other layers and possibly contaminated the PETM layers during the drilling process.

    See the full article here .

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  • richardmitnick 8:17 am on June 22, 2016 Permalink | Reply
    Tags: , , Smithsonian.com   

    From Smithsonian: “Kill All the Mosquitoes?!” 


    June 2016
    Jerry Adler
    Photographs by David Yoder

    Environmental cues mosquitoes to swarm inside a lab. (David Yoder)

    To the naked eye, the egg of the Anopheles gambiae mosquito is just a dark speck, but under a 100-power microscope, it shows up as a fat, slightly curved cucumber, somewhat narrower at one end. In the wild, it is typically found in shallow, sunlit puddles in sub-Saharan Africa, but it can survive in any number of wet places at around 80 degrees Fahrenheit. In a laboratory in London, behind three sets of locked doors enclosing negative-pressure containment vestibules, Andrew Hammond, a doctoral student in molecular genetics, picks up a clump of Anopheles eggs on a small paintbrush and lines them up on a microscope slide. Hammond looks for the narrow end, where the germ line cells that will form the next generation are located. With delicate nudges of a joystick, he maneuvers a tiny needle through his field of vision until it just penetrates the egg membrane, and the click of a button releases a minute squirt of DNA. Whether the genetic material reaches and binds to its target region is then a matter of luck, and luck is, generally, with the mosquito. Hammond’s success rate, of which he is very proud, is around 20 percent.

    A. gambiae has been called the world’s most dangerous animal, although strictly speaking that applies only to the female of the species, which does the bloodsucking and harms only indirectly. Its bite is a minor nuisance, unless it happens to convey the malaria parasite, Plasmodium falciparum, for which it is a primary human vector. Although a huge international effort has cut malaria mortality by about half since 2000, the World Health Organization still estimates there were more than 400,000 fatal cases in 2015, primarily in Africa. Children are particularly susceptible. The Bill and Melinda Gates Foundation prioritized malaria in its more than $500 million commitment to fight infectious disease in developing countries. A portion of that money ends up here, in the laboratory of Andrea Crisanti at Imperial College, London, a short walk from Harrods.

    Crisanti, a tousled, sad-eyed man with a gentle smile, was trained as a physician in Rome. Later, studying molecular biology in Heidelberg, he developed his lifelong interest in malaria. He set out on the trail of A. gambiae some 30 years ago, after he concluded that the best way to eradicate the disease was to attack the mosquito rather than the parasite. “The vector is the Achilles’ heel of the disease,” he says in his soft Italian accent. “If you go after the pathogen [with drugs], all you are doing is generating resistance.”

    Humans have been at war with members of the family Culicidae for over a century, since the pioneering epidemiologist Sir Ronald Ross proved the role of Anopheles in malaria and U.S. Army Maj. Walter Reed made a similar discovery about Aedes aegypti and yellow fever. The war has been waged with shovels and insecticides, with mosquito repellent, mosquito traps and mosquito-larvae-eating fish, with bed nets and window screens and rolled-up newspapers. But all of these approaches are self-limiting. Puddles fill up again with rain; insects evolve resistance to pesticides; predators can eat only so much.

    By the time Crisanti joined Imperial College, in 1994, molecular genetics had suggested a new approach, which he was quick to adopt, and in which his lab is now among the most advanced in the world. Scientists had discovered how to insert beneficial mutations—such as the gene for Bt, a natural insecticide—into agricultural crops such as corn. Why not, then, create a lethal mutation and insert it into the DNA of a mosquito? One problem was that mosquitoes weren’t bred in a factory, as commodity corn increasingly is. In the wild, mosquitoes mate randomly and propagate by Mendelian inheritance, which dictates that a mutation spreads slowly, if at all. Unless the man-made mutation conveyed some strong evolutionary advantage—and the whole point was to do the opposite—it would most likely disappear.

    In 2003, Austin Burt, a colleague of Crisanti’s at Imperial College, suggested a solution: coupling the desired mutation with a “gene drive” that would overwrite the ordinary processes of inheritance and evolution. Recall that genes are spelled out by DNA sequences woven into chromosomes, which come in pairs (23 pairs in a human, 3 in a mosquito). A “gene drive” involves copying a mutated gene from one chromosome onto the other member of the pair. The key is that when the pairs split to form the eggs and sperm, it won’t matter which chromosome gets passed along—the engineered gene will be there either way. Thus a single mutation would, in theory, be “driven” into practically every mosquito in a breeding population.For the next dozen years, Crisanti, working with a senior research fellow named Tony Nolan and others, obsessively pursued variations of this approach, designing one gene mutation that would render females sterile and another that would lead to a huge preponderance of males. The challenge was creating the particular gene drives that duplicated those mutations—a tedious, years-long process of constructing custom DNA-snipping enzymes.

    Then, in 2012, the UC Berkeley researcher Jennifer Doudna and her colleagues developed a revolutionary new technique for editing DNA. Researchers had known for years that certain genes in bacteria had short, repeating chunks of DNA. (CRISPR stands for “clustered regularly interspaced short palindromic repeats.”) When a virus invaded, the bacteria copied part of the virus’ genetic code, slotting it into the spaces between the repeating CRISPR chunks. The next time the bacteria saw that piece of code, an enzyme called Cas9 would guide its RNA to exactly that sequence in the gene of the invading virus. It would cut out the DNA with incredible precision and fuse the strand back together. Doudna and her colleagues harnessed this process in the lab, using it to quickly and easily edit any part of a gene they targeted. The following year, separate teams led by MIT bioengineer Feng Zhang and Harvard’s George Church showed it would work in living cells.

    It was the universality as well as the accuracy that set CRISPR-Cas9 apart from other gene-editing techniques. Unlike the custom enzymes Crisanti and his team had been painstakingly building, Cas9 seemed to work in any type of cell. Researchers saw implications for treating genetic disorders, for improving agriculture—and for more sinister applications, such as creating biowarfare agents. CRISPR also brought Crisanti’s dream a giant step closer to reality. Now, he and his team could program Cas9’s guide RNA to pinpoint any part of a gene and transfer over the material they wanted to copy.

    In a study published last year, Andrea Crisanti, right, and his colleagues were able to spread an infertility mutation to 75 percent of a mosquito population. (Mike Kemp / Bill & Melinda Gates Foundation)

    If Crisanti’s approach works, you could, in theory, wipe out an entire species of mosquito. You could wipe out every species of mosquito, although you’d need to do them one at a time, and there are around 3,500 of them, of which only about 100 spread human disease. You might want to stop at fewer than a dozen species in three genera—Anopheles (translation: “useless,” the malaria mosquito), Aedes (translation: “unpleasant,” the principal vector for yellow fever, dengue and Zika) and Culex (translation: “gnat,” responsible for spreading West Nile, St. Louis encephalitis and other viruses).

    For thousands of years, the relentlessly expanding population of Homo sapiens has driven other species to extinction by eating them, shooting them, destroying their habitat or accidentally introducing more successful competitors to their environment. But never have scientists done so deliberately, under the auspices of public health. The possibility raises three difficult questions: Would it work? Is it ethical? Could it have unforeseen consequences?


    The feasibility question is being studied in Crisanti’s London lab, where the injected eggs will hatch into larvae. The ones harboring the mutation are identified by a “marker” gene, which glows under a microscope when viewed in certain lights. The mutants of interest are then returned to the warm, humid air of the mosquito rooms, to stacked trays with walls of white plastic mesh. On one side, there’s a long socklike tube, ordinarily tied in a knot, through which researchers can insert an aspirator to gently vacuum up specimens. If you hold your hand nearby, the females, sensing the nearness of blood, gather on that side. When it’s time for their blood meal, which will nourish the hundred or so eggs a female will lay at one time, an anesthetized mouse is laid belly-down on the cage roof, and the females fly up to bite it through the mesh. (The males, which live on nectar and fruit in the wild, feed on a glucose-water solution, wicked up from a small glass bottle.) These insects live up to a month longer in the controlled environment of the cages than in the wild, where they often don’t survive more than a week or two.

    The next phase of the research takes place in Perugia, Italy, home to one of the world’s oldest universities, founded in 1308, and to a small, elite research consortium, Polo d’Innovazione Genomica. A few miles from the winding alleys of the medieval hilltop village, in a glass-walled building on a stark windswept plaza, is Polo’s secure lab, with six ceiling-high “field cages,” each with an area of 50 or 60 square feet. Signs on the doors warn away visitors who might have been exposed to malaria, since they could infect an escaped mosquito if it bit them. The air inside is tropical. Instead of live mice, females are fed on small dishes of bovine blood, warmed to body temperature and covered with paraffin, to give them something to land on. The females are attracted to the pheromones in human sweat, especially from the feet. Lab workers say they sometimes wear their socks all weekend and bring them to work on Monday to rub on the feeding dishes.

    Inside, the lighting changes to simulate a 24-hour tropical day, and environmental cues trigger the swarming behavior that is crucial to mating. “That is how many insects mate,” explains the chief entomologist, Clelia Oliva. “The males swarm, and the females fly through the swarm and find a mate, and they come together in the air. If you cannot replicate that, you cannot determine if your line is going to succeed in the wild.” An escapee from one of the cages flits past Oliva as she is talking, and she dispatches it with the slap she perfected while studying mosquitoes on Reunion Island, in the Indian Ocean.

    Researchers are skeptical about whether it is even possible to wipe out mosquitoes. “Global elimination of an entire species, I think, is a little far-fetched,” says Steven Juliano, an ecologist at Illinois State University. But, he adds, “I think they have a good chance of reducing local populations, maybe even eradicating a species in a locality.”

    Something like that has been done with other creatures. Starting in the 1950s, the American entomologists Edward F. Knipling and Raymond C. Bushland eliminated the screwworm, an agricultural pest, from the United States and much of Central America. Their approach, called “sterile insect technique,” involved breeding and hatching millions of flies, sterilizing the males with low-level gamma rays, then releasing them in numbers sufficient to swamp the wild population. Females that mated with the sterile males produced infertile offspring. It took decades, but it worked—the two men were awarded the World Food Prize in 1992—and the same technique now is used to contain outbreaks of the Mediterranean fruit fly.

    But when the sterile insect technique was tried against mosquitoes, the results were mixed. It requires that the released males compete successfully with their wild counterparts in mating, and there is evidence that in mosquitoes, the same radiation that makes them sterile may also impair their mating behavior. Whatever female mosquitoes are looking for in a mate, these males seem to have less of it.

    So researchers have also been looking at variants of sterile insect technology that don’t require radiation. A pilot project has begun in the city of Piracicaba, in southeastern Brazil, by the British biotech company Oxitec. The target insect is A. aegypti, the main culprit in spreading yellow fever, dengue and other viral diseases, and the work has taken on greater urgency in the last six months, because A. aegypti also is a vector for the Zika virus, blamed for an outbreak of terrifying birth defects in the Americas.

    In Oxitec’s program, male larvae bred with a lethal mutation are raised in water dosed with the antibiotic tetracycline, which inactivates the lethal gene. When those males mate with wild mosquitoes, their offspring, deprived of tetracycline, die before they can reproduce. CEO Hadyn Parry claims “greater than 90 percent suppression of the wild population” in five studies that covered relatively small areas in Brazil, Panama and the Cayman Islands. Now the company wants to expand to the subtropical U.S., and it recently passed a key regulatory hurdle to bring the program to the Florida Keys.

    Oxitec’s technology predates CRISPR, and it doesn’t use a gene drive. Its goal is not to exterminate Aedes, but to reduce the local population to where it can no longer serve as a vector for human disease. That is, of course, a temporary solution to a perennial problem. Mosquitoes don’t usually travel more than a few hundred yards from where they hatch, but people do, and they can take yellow fever with them. And the mosquitoes themselves can travel the globe on airplanes and ships. Aedes albopictus, the “Asian tiger mosquito,” arrived in the Western Hemisphere a few years ago, possibly in a shipment of tires, and spreads many of the same diseases as A. aegypti. So even if the Oxitec program succeeds, it will likely need to be repeated at intervals. “You begin to see why Oxitec is a business,” one American entomologist said dryly.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    Smithsonian magazine and Smithsonian.com place a Smithsonian lens on the world, looking at the topics and subject matters researched, studied and exhibited by the Smithsonian Institution — science, history, art, popular culture and innovation — and chronicling them every day for our diverse readership.

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