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  • richardmitnick 8:53 am on February 11, 2018 Permalink | Reply
    Tags: , , , , , EarthSky,   

    From EarthSky: “Somber Betelgeuse in Orion’s shoulder” 

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    EarthSky

    February 11, 2018

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    Tonight, look for ruddy-hued Betelgeuse, one of the sky’s most famous stars. Kids especially like Betelgeuse, because its name sounds so much like beetle juice. The movie by that same name perpetuated this pronunciation.

    But astronomers pronounce it differently. We say BET-el-jews.

    People have described this star as somber or sometimes even grandfatherly. That may be because of Betelgeuse’s ruddy complexion, which, as a matter of fact, indicates that this star is well into the autumn of its years.

    Betelgeuse is no ordinary red star. It’s a magnificently rare red supergiant. According to Professor Jim Kaler – whose website Stars you should check out – there might be only one red supergiant star like Betelgeuse for every million or so stars in our Milky Way galaxy.

    At this time of year, Betelgeuse’s constellation – Orion the Hunter – ascends to its highest point in the heavens around 8 to 9 p.m. local time – that’s the time on your clock no matter where you are on the globe – with the Hunter symbolically reaching the height of his powers.

    As night passes – with Earth turning eastward under the stars – Orion has his inevitable fall, shifting lower in the sky by late evening.

    Orion slowly heads westward throughout the late evening hours and plunges beneath the western horizon in the wee hours after midnight.

    Orion Nebula ESO/VLT

    Bottom line: The ruddy star Betelgeuse depicts Orion’s shoulder. In mid-February, Orion reaches his high point for the night around 8 to 9 p.m. local time.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

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  • richardmitnick 9:00 am on February 10, 2018 Permalink | Reply
    Tags: , EarthSky, Is a major California earthquake overdue?, ,   

    From EarthSky: “Is a major California earthquake overdue?” 

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    EarthSky

    February 3, 2018
    Richard Aster, Colorado State University

    According to current forecasts, California has a 93% chance of an earthquake of magnitude 7 or greater occurring by 2045.

    California earthquakes are a geologic inevitability. The state straddles the North American and Pacific tectonic plates and is crisscrossed by the San Andreas and other active fault systems. The magnitude 7.9 earthquake that struck off Alaska’s Kodiak Island on Jan. 23, 2018, was just the latest reminder of major seismic activity along the Pacific Rim.

    Tragic quakes that occurred in 2017 near the Iran-Iraq border and in central Mexico, with magnitudes of 7.3 and 7.1, respectively, are well within the range of earthquake sizes that have a high likelihood of occurring in highly populated parts of California during the next few decades.

    The earthquake situation in California is actually more dire than people who aren’t seismologists like myself may realize. Although many Californians can recount experiencing an earthquake, most have never personally experienced a strong one. For major events, with magnitudes of 7 or greater, California is actually in an earthquake drought. Multiple segments of the expansive San Andreas Fault system are now sufficiently stressed to produce large and damaging events.

    The good news is that earthquake readiness is part of the state’s culture, and earthquake science is advancing – including much improved simulations of large quake effects and development of an early warning system for the Pacific coast.

    The last big one

    California occupies a central place in the history of seismology. The April 18, 1906, San Francisco earthquake (magnitude 7.8) was pivotal to both earthquake hazard awareness and the development of earthquake science – including the fundamental insight that earthquakes arise from faults that abruptly rupture and slip. The San Andreas Fault slipped by as much as 20 feet (six meters) in this earthquake.

    Although ground-shaking damage was severe in many places along the nearly 310-mile (500-kilometer) fault rupture, much of San Francisco was actually destroyed by the subsequent fire, due to the large number of ignition points and a breakdown in emergency services. That scenario continues to haunt earthquake response planners. Consider what might happen if a major earthquake were to strike Los Angeles during fire season.

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    Collapsed Santa Monica Freeway bridge across La Cienega Boulevard, Los Angeles, after the Northridge earthquake January 17, 1994. Image via Robert A. Eplett/FEMA.

    Seismic science

    When a major earthquake occurs anywhere on the planet, modern global seismographic networks and rapid response protocols now enable scientists, emergency responders and the public to assess it quickly – typically, within tens of minutes or less – including location, magnitude, ground motion and estimated casualties and property losses. And by studying the buildup of stresses along mapped faults, past earthquake history, and other data and modeling, we can forecast likelihoods and magnitudes of earthquakes over long time periods in California and elsewhere.

    However, the interplay of stresses and faults in the Earth is dauntingly chaotic. And even with continuing advances in basic research and ever-improving data, laboratory and theoretical studies, there are no known reliable and universal precursory phenomena to suggest that the time, location and size of individual large earthquakes can be predicted.

    Major earthquakes thus typically occur with no immediate warning whatsoever, and mitigating risks requires sustained readiness and resource commitments. This can pose serious challenges, since cities and nations may thrive for many decades or longer without experiencing major earthquakes.

    California’s earthquake drought

    The 1906 San Francisco earthquake was the last quake greater than magnitude 7 to occur on the San Andreas Fault system.

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    San Andreas Fault in the Carrizo Plain, aerial view from 8500 feet altitude. http://ian.kluft.com/pics/mojave/20071116/img_0327.jpg

    The inexorable motions of plate tectonics mean that every year, strands of the fault system accumulate stresses that correspond to a seismic slip of millimeters to centimeters. Eventually, these stresses will be released suddenly in earthquakes.

    But the central-southern stretch of the San Andreas Fault has not slipped since 1857, and the southernmost segment may not have ruptured since 1680. The highly urbanized Hayward Fault in the East Bay region has not generated a major earthquake since 1868.

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    English: w:en:Hayward Fault Zone map, derived from USCGS 122-38 image. http://quake.wr.usgs.gov.

    Reflecting this deficit, the Uniform California Earthquake Rupture Forecast estimates that there is a 93 percent probability of a 7.0 or larger earthquake occurring in the Golden State region by 2045, with the highest probabilities occurring along the San Andreas Fault system.

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    Perspective view of California’s major faults, showing forecast probabilities estimated by the third Uniform California Earthquake Rupture Forecast. The color bar shows the estimated percent likelihood of a magnitude 6.7 or larger earthquake during the next 30 years, as of 2014. Note that nearly the entire San Andreas Fault system is red on the likelihood scale due to the deficit of large earthquakes during and prior to the past century. Image via USGS.

    California’s population has grown more than 20-fold since the 1906 earthquake and currently is close to 40 million. Many residents and all state emergency managers are widely engaged in earthquake readiness and planning. These preparations are among the most advanced in the world.

    For the general public, preparations include participating in drills like the Great California Shakeout, held annually since 2008, and preparing for earthquakes and other natural hazards with home and car disaster kits and a family disaster plan.

    No California earthquake since the 1933 Long Beach event (6.4) has killed more than 100 people. Quakes in 1971 (San Fernando, 6.7); 1989 (Loma Prieta; 6.9); 1994 (Northridge; 6.7); and 2014 (South Napa; 6.0) each caused more than US$1 billion in property damage, but fatalities in each event were, remarkably, dozens or less. Strong and proactive implementation of seismically informed building codes and other preparations and emergency planning in California saved scores of lives in these medium-sized earthquakes. Any of them could have been disastrous in less-prepared nations.

    Above: Remington Elementary School in Santa Ana takes part in the 2015 Great California Shakeout.

    Nonetheless, California’s infrastructure, response planning and general preparedness will doubtlessly be tested when the inevitable and long-delayed “big ones” occur along the San Andreas Fault system. Ultimate damage and casualty levels are hard to project, and hinge on the severity of associated hazards such as landslides and fires.

    Several nations and regions now have or are developing earthquake early warning systems, which use early detected ground motion near a quake’s origin to alert more distant populations before strong seismic shaking arrives. This permits rapid responses that can reduce infrastructure damage. Such systems provide warning times of up to tens of seconds in the most favorable circumstances, but the notice will likely be shorter than this for many California earthquakes.

    Early warning systems are operational now in Japan, Taiwan, Mexico and Romania. Systems in California and the Pacific Northwest are presently under development with early versions in operation. Earthquake early warning is by no means a panacea for saving lives and property, but it represents a significant step toward improving earthquake safety and awareness along the West Coast.

    The earthquake risk requires a resilient system of social awareness, education and communications, coupled with effective short- and long-term responses and implemented within an optimally safe built environment. As California prepares for large earthquakes after a hiatus of more than a century, the clock is ticking.

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States

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    The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

    Watch a video describing how ShakeAlert works in English or Spanish.

    The primary project partners include:

    United States Geological Survey
    California Governor’s Office of Emergency Services (CalOES)
    California Geological Survey
    California Institute of Technology
    University of California Berkeley
    University of Washington
    University of Oregon
    Gordon and Betty Moore Foundation

    The Earthquake Threat

    Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

    Part of the Solution

    Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

    Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

    System Goal

    The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

    Current Status

    The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

    In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

    This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

    Authorities

    The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

    For More Information

    Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
    rdegroot@usgs.gov
    626-583-7225

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

    Quake-Catcher Network

    You can help many citizen scientists in detecting earthquakes and getting the data to emergency services people in affected area.
    QCN bloc

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    BOINCLarge

    BOINC WallPaper

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 1:39 pm on February 5, 2018 Permalink | Reply
    Tags: "Volcán de Fuego from Earth and space, , EarthSky,   

    From EarthSky: “Volcán de Fuego from Earth and space” 

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    EarthSky

    February 5, 2018
    Deborah Byrd
    Eleanor Imster

    Volcán de Fuego – literally “fire volcano” – is one of Central America’s most active volcanos. Photos of its recent eruption here.

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    February 1, 2018, satellite image – in natural color – of a burst from Volcán de Fuego. Ash in a volcanic plume typically appears brown or gray in space images, while steam appears white. Image via Landsat 8 and NASA Earth Observatory.

    NASA LandSat 8

    Guatemala’s Volcán de Fuego began a new round of explosive activity on January 31, 2018. This volcano – located about 40 miles (70 km) west of Guatemala City – is known for its explosive activity, spreading ash plumes, and spectacular lava flows. This eruption was its first of 2018. It ended after about 20 hours of activity.

    The Operational Land Imager (OLI) on Landsat 8 captured the natural-color image above of the eruption.

    NASA Operational Land Imager on LandSat 8

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    As the eruption of Volcán de Fuego progressed, lava poured down the slopes of the volcano. This view is from the municipality of Alotenango, Sacatepéquez, Guatemala, on February 1, 2018. Image via Esteban Biba (EFE)/ El País.

    NASA said:

    “According to the Coordinadora Nacional para la Reducción de Desastres (CONRED), the plume reached an altitude of 21,300 feet (6,500 meters) above sea level and was carried 25 miles (40 km) to the west and southwest by the winds. Falling ash affected tens of thousands of people, primarily in the provinces of Escuintla and Chimaltenango. Lava from two active conduits flowed through four ravines, leading officials to preemptively close National Route 14 to vehicles.”

    NASA also reported on components of the ash cloud. The plume contains gaseous components invisible to the human eye, including sulfur dioxide SO2. NASA explained:

    “The gas can affect human health—irritating the nose and throat when breathed in—and reacts with water vapor to produce acid rain. It also can react in the atmosphere to form aerosol particles, which can contribute to outbreaks of haze and influence the climate.”

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    February 1, 2018 image of Volcán de Fuego via Landsat 8 and NASA Earth Observatory.

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    This map shows concentrations of SO2 detected on February 1, 2018, by the Ozone Mapper Profiler Suite (OMPS) on the Suomi National Polar-orbiting Partnership (Suomi-NPP) satellite. Image via NASA Earth Observatory.

    NASA Goddard Suomi-NPP satellite

    Volcán de Fuego is famous for being almost constantly active at a low level. On any given day, you might see smoke rising from its peak. Larger eruptions are less common, but have been seen for centuries.

    Read more from NASA Earth Observatory

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 12:15 pm on January 28, 2018 Permalink | Reply
    Tags: , , , , EarthSky, Europa moon,   

    From EarthSky: “Will future landers on Europa sink?” 

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    EarthSky

    January 28, 2018
    Deborah Byrd

    Jupiter’s moon Europa is an ocean world beneath an icy crust, and scientists want to land a spacecraft there. But a new study indicates a surface less dense than freshly fallen snow.

    Space scientists have every reason to be fascinated with Jupiter’s moon Europa, and, in 2017, NASA and the European Space Agency (ESA) announced they are planning a joint mission to land there. As the video above explains, this little moon is thought to have a liquid ocean submerged beneath an icy crust. Scientists believe it could host extraterrestrial life. But Europa’s surface is much more alien than any we’ve ever visited. With its extremely thin atmosphere, low gravity – and a surface temperature of some -350 degrees F. (–176 °C.) – Europa might not be kind to a landing spacecraft. The moon’s surface might be unexpectedly hard. Or – as evidenced by a study from the Planetary Science Institute announced on January 24, 2018 – Europa’s surface might be so porous that any craft trying to land would simply sink.

    The study – published in the peer-reviewed journal Icarus – comes from scientist Robert Nelson. If you’re a student of space history, its results might sound familiar. Nelson pointed out in his statement:

    “Of course, before the landing of the Luna 2 robotic spacecraft in 1959, there was concern that the moon might be covered in low density dust into which any future astronauts might sink.”

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    Luna 2 Soviet moon probe. NASA.

    Now Europa is the source of a similar scariness, with Nelson’s study showing that Europa’s surface could be as much as 95 percent porous.

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    The puzzling, fascinating surface of Jupiter’s icy moon Europa. This color composite is made from images taken by NASA’s Galileo spacecraft in the late 1990s. Image via NASA/JPL-Caltech/SETI Institute.

    NASA/Galileo 1989-2003

    Nelson’s study of Europa is part of a group of studies he has conducted of both asteroids (44 Nysa, 64 Angelina) and jovian moons (Io, Europa, Ganymede). He conducts his studies via photopolarimetry, the measurement of the intensity and polarization of reflected light.

    Observations were made using a photopolarimeter located at Mt. San Antonio College in Walnut, California.

    According to Nelson, the observations can be explained by extremely fine-grained particles on Europa’s surface with a porosity less than about 95 percent. This corresponds to material that would be less dense than freshly fallen snow, raising questions about risks of sinking for a future Europa lander.

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    Brown ridges crisscross Europa, indicating the possibility of liquid welling up from below. This suggests an active geology and raises questions about possible life on Europa. Image via NASA/PLAN-PIA01641.

    A mission to land on Europa is challenging in other ways. For example, Europa — along with the three other Galilean moons (Io, Ganymede and Callisto) — orbits within Jupiter’s radiation belts. A spacecraft trying to orbit Europa would be quickly fried.

    That’s why NASA’s upcoming Europa Clipper mission is designed to orbit Jupiter, not Europa.

    NASA/Europa Clipper

    It’ll sweep in and out of the radiation belts for a period of several earthly years, making flyby observations of Europa each time it passes near this jovian moon. Its observations will help answer questions about what might happen to future spacecraft attempting to land on Europa.

    The video below has more about the upcoming flyby mission, Europa Clipper, set for launch around 2022-2025.

    Bottom line: A recent study via the Planetary Science Institute indicates that the surface of Jupiter’s moon Europa might be as much as 95 percent porous – less dense than freshly fallen snow – so that a future lander might sink.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 8:48 am on January 24, 2018 Permalink | Reply
    Tags: , , , , EarthSky,   

    From EarthSky: “Orion Nebula is a place where new stars are being born” 

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    EarthSky

    January 23, 2018
    Bruce McClure

    Everything you need to know about the Orion Nebula. How to find it in your sky tonight. Plus … the science of this star factory in space.

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    Stefan Nilsson captured this image in southern Sweden on January 2, 2017. You can recognize the constellation Orion by his three Belt stars, three stars in a short, straight row. The Orion Nebula is that red fuzzy region in Orion’s Sword, hanging from the Belt.

    Many people are familiar with Orion, the most noticeable of all constellations. The three stars of Orion’s Belt jump out at you midway between Orion’s two brightest stars, Betelgeuse and Rigel, which are two of the brightest stars in the sky. Once you find the Belt stars, you can also locate the Orion Nebula, otherwise known as M42, a stellar nursery where new stars are being born. Follow the links below to learn more about the Orion Nebula.

    How to locate the Orion Nebula.

    What science says about the Orion Nebula.

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    The three medium-bright stars in a short, straight row represent Orion’s Belt. A curved line of stars extending from the Belt represents Orion’s Sword. The Orion Nebula lies about midway down in the Sword of Orion. Image via Marian McGaffney.

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    Orion Nebula captured on February 5, 2016, by Scott MacNeill at Frosty Drew Observatory in Charlestown, Rhode Island. Scott said this image is a composite of 25 shots.

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    Frosty Drew Observatory in Charlestown, Rhode Island, USA.

    How to locate the Orion Nebula. If you want to find this famous nebula, first you have to locate the constellation Orion. Fortunately, that’s easy, if you’re looking at the right time of year. The Northern Hemisphere winter months (Southern Hemisphere summer months) are the perfect time to come to know Orion.

    The constellation is noticeable for three medium-bright stars in a short, straight row. These stars represent Orion’s Belt.

    If you look closely, you’ll notice a curved line of stars “hanging” from the three Belt stars. These stars represent Orion’s Sword. Look for the Orion Nebula about midway down in the Sword of Orion.

    As a general rule, the higher the constellation Orion is in the sky, the easier it is to see the Orion Nebula. From Northern Hemisphere locations, Orion is due south and highest in the sky around midnight in middle December. The stars return to the same place in the sky some 4 minutes earlier each night, or 2 hours earlier each month. So look for Orion to be highest up around 10 p.m. in mid-January and 8 p.m. in mid-February.

    Another time people notice Orion is around the months of August and September, when this constellation appears in the east before dawn.

    Most nebulae – clouds of interstellar gas and dust – are difficult if not impossible to see with the unaided eye or even binoculars. But the Orion Nebula is in a class nearly all by itself. It’s visible to the unaided eye on a dark, moonless night. To me, it looks like a star encased in a globe of luminescent fog. The dark-sky aficionado Stephen James O’Meara described it as:

    … angel’s breath against a frosted sky.

    In a dark country sky, observe the Orion Nebula for yourself to see what it looks like. A backyard telescope, or even binoculars, do wonders to showcase one of the greatest celestial treasures in the winter sky.

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    This spectacular image of the Orion Nebula star-formation region was obtained from multiple exposures using the HAWK-I infrared camera on ESO’s Very Large Telescope in Chile. Image via ESO/H. Drass et al.

    ESO HAWK-I on the ESO VLT

    ESO VLT Platform at Cerro Paranal elevation 2,635 m (8,645 ft)

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    The Orion Nebula, 1,500 light years from Earth. Image via NASA/JPL-Caltech/STScI.

    What science says about the Orion Nebula. According to modern astronomers, the Orion Nebula is an enormous cloud of gas and dust, one of many in our Milky Way galaxy. It lies roughly 1,300 light-years from Earth.

    At some 30 to 40 light-years in diameter, this great big nebulous cocoon is giving birth to perhaps a thousand stars. A young open star cluster, whose stars were born at the same time from a portion of the nebula and are still loosely bound by gravity, can be seen within the nebula. It is sometimes called the Orion Nebula Star Cluster. In 2012, an international team of astronomers suggested this cluster in the Orion Nebula might have a black hole at its heart.

    The four brightest stars in the Orion Nebula can be seen through amateur astronomers’ telescopes and are affectionately known as The Trapezium. The light of the young, hot Trapezium stars illuminate the Orion Nebula. These stars are only a million or so years old – babies on the scale of star lifetimes.

    But most of the stars in this emerging cluster are veiled behind the Orion Nebula itself, the great stellar nursery in Orion’s Sword.

    Orion Nebula’s position is Right Ascension: 5h 35.4m; Declination: 5o 27′ south

    Bottom line: To find the Orion Nebula in your night sky, look below Orion’s Belt. Your eye sees it as a tiny, hazy spot, but it’s a vast region of star formation.

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 9:35 am on January 23, 2018 Permalink | Reply
    Tags: , , EarthSky, Tsunami warnings issued – later canceled – after powerful Alaska quake   

    From EarthSky: “Tsunami warnings issued – later canceled – after powerful Alaska quake” 

    1

    EarthSky

    January 23, 2018
    Deborah Byrd

    A powerful earthquake struck 174 miles (280 km) southeast of Kodiak, Alaska early this morning. Tsunami watches or warnings were issued – later cancelled – for the western North America and Hawaii.

    1
    A National Weather Service map showing the red tsunami warning zone as well as the yellow tsunami watch zone of January 23, 2018. The original watches and warnings ran south from Alaska, into Washington and California and also included Hawaii. At this writing (12:30 UTC, or 6:30 EST), no tsunami watch, warning or advisory is in effect according to the Pacific Tsunamic Warning Center.

    The U.S. Geological Survey (USGS) reported a very large earthquake this morning in the Gulf of Alaska. It was originally reported at 8.2 magnitude, then 7.9 magnitude, then downgraded further to 7.0; even at the lowest number, it’s still a powerful quake (though much less powerful than originally reported). The earthquake struck on January 23, 2018 at 9:31 UTC (3:31 a.m. CST). It occurred 174 miles (280 km) southeast of Kodiak, Alaska.

    The Pacific Tsunami Warning Center (PTWC) issued tsunami watches or warnings for large portions of the Pacific, including a watch for the U.S. west coast from Washington to California as well as Hawaii, and a tsunami warning for the coast of Alaska and the Canadian province of British Columbia. Subsequently, all watches and warnings were cancelled, but not before a mass of confusion on Twitter and other news outlets.

    There were reports of some panic in Kodiak, Alaska (sirens blaring, people being woken from sleep), near the quake’s epicenter. Waters were then said to be receding in Kodiak, and waves were said to have been “small.”

    We have not yet seen reports of damages or injuries from this event.

    The PTWC – which was still in its calculation process when this advisory was issued at 10:17 UTC (4:17 a.m. CST) today – said tsunami waves were originally forecast to be less than one foot (0.3 meters) above the tide level for the coasts of Guam, Hawaii and northwestern Hawaiian Islands, Japan, Johnston Atoll, Mexico, Midway Island, Northern Marianas, Russia, and Wake Island.

    This story is still being updated.

    4
    Aftershocks will follow an earthquake this size. Resident of both Alaska and Canada should be prepared. Sometimes aftershocks can be even stronger than the initial earthquake. Daniel McFarland‏

    Large earthquakes are common in the Pacific-North America plate boundary region south of Alaska. USGS explained:

    The January 23, 2018 M 7.9 earthquake southeast of Kodiak Island in the Gulf of Alaska occurred as the result of strike slip faulting within the shallow lithosphere of the Pacific plate … At the location of the earthquake, the Pacific plate is converging with the North America plate at a rate of approximately 59 mm/yr towards the north-northwest. The Pacific plate subducts beneath the North America plate at the Alaska-Aleutians Trench, about 90 km to the northwest of today’s earthquake. The location and mechanism of the January 23rd earthquake are consistent with it occurring on a fault system within the Pacific plate before it subducts, rather than on the plate boundary between the Pacific and North America plates further to the northwest.

    Bottom line: A 7.9-magnitude earthquake struck on January 23, 2018 in the Gulf of Alaska. Tsunami watches and warnings issued. The situation is still unfolding.

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 8:54 am on January 18, 2018 Permalink | Reply
    Tags: , , , , EarthSky, Goethe University Frankfurt, How massive can neutron stars be?   

    From EarthSky:”How massive can neutron stars be?” 

    1

    EarthSky

    January 18, 2018
    Deborah Byrd

    Settling a long debate, astrophysicists at Goethe University Frankfurt now say neutron stars can’t exceed the mass of 2.16 suns.

    1
    Gravitational-wave emission from a collapsing star, via Goethe University.

    In 2016, when the twin LIGO detectors made their first historic observation of gravitational waves, astronomers heralded the news both as a confirmation of Einstein’s general relativity and also because, as they love to say, the detection:

    … opened a new window on the cosmos.

    And indeed that window has begun to crack. On January 16, 2018, astrophysicists at Goethe University in Frankfurt, Germany described how they used observations of gravitational waves to answer a question that’s plagued scientists since the 1960s, when they first discovered neutron stars, or stars composed predominantly of closely packed neutrons. By definition, a neutron star has a very small radius (about the diameter of an earthly city) and very high density (a teaspoon of neutron star material would weigh about 10 million tons). A typical neutron star mass is about 1.4 suns.

    Notice all the abouts in those last couple of sentences? Now, for the first time, astrophysicists are saying they’ve succeeded in putting more precision into those numbers, by calculating a strict upper limit for the maximum mass of neutron stars. They say that, with an accuracy of a few percent, the maximum mass of non-rotating neutron stars cannot exceed 2.16 solar masses.

    The research results were published in the peer-reviewed The Astrophysical Journal Letters, and, according to these scientists:

    Just a few days later, research groups from the USA and Japan confirmed the findings, despite having so far followed different and independent approaches.

    What happens to a neutron star that does exceed its mass limit? In that case, the neutron star collapses into an even more compressed and vastly more exotic object known as a black hole.

    Physicist Luciano Rezzolla at Goethe University Frankfurt and his students Elias Most and Lukas Weih conducted the study. Their statement explained:

    The basis for this result was the ‘universal relations’ approach [described here] developed in Frankfurt a few years ago. The existence of ‘universal relations’ implies that practically all neutron stars ‘look alike,’ meaning that their properties can be expressed in terms of dimensionless quantities. The researchers combined these ‘universal relations’ with data on gravitational-wave signals and the subsequent electromagnetic radiation (kilonova) obtained during the observation last year of two merging neutron stars in the framework of the LIGO experiment.

    In the near-term future, these scientists expect more observations via gravitational-wave astronomy, which will further reduce uncertainties about neutron stars’ maximum mass. In the meantime, they said, their result is a good example of the interaction between theoretical and experimental research. Rezzolla commented:

    The beauty of theoretical research is that it can make predictions. Theory, however, desperately needs experiments to narrow down some of its uncertainties. It’s therefore quite remarkable that the observation of a single binary neutron star merger that occurred millions of light-years away – combined with the universal relations discovered through our theoretical work – have allowed us to solve a riddle that has seen so much speculation in the past.

    Bottom line: Settling a long debate, astrophysicists at Goethe University Frankfurt now say neutron stars can’t exceed the mass of 2.16 suns. Add more mass, and a neutron star becomes a black hole.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 10:25 am on December 11, 2017 Permalink | Reply
    Tags: Astronomers chart galaxy orbits in our Local Supercluster, , , , , EarthSky, ,   

    From EarthSky: “Astronomers chart galaxy orbits in our Local Supercluster” 

    1

    EarthSky

    December 10, 2017
    Deborah Byrd

    4
    In the [interactive in the full article, image above], you’ll notice the galaxies are moving toward something, a gravitational attractor represented by the big red dot more or less in the center of the mapped area (and in purple in the still graphic just above). This attractor is the Virgo Cluster, a large cluster of galaxies at the heart of the Virgo Supercluster (all located in the direction to the constellation Virgo in our sky; hence their names).

    Our home Milky Way galaxy (MW, yellow) and our companion Andromeda galaxy (M31, red) are participating in a downward flow away from a vast underdense region called the Local Void and toward the Virgo Cluster, represented by the large purple dot in this image. Most galaxies between us and the Virgo Cluster will eventually fall into the cluster but we lie slightly beyond the capture zone. Image via R. Brent Tully/ Institute for Astronomy, U Hawaii.

    “For the first time, we are not only visualizing the detailed structure of our Local Supercluster of galaxies, but we are also seeing how the structure developed over the history of the universe.”

    Look at the [above] graphic, for the yellow letters marked MW. Our Milky Way is part of what’s called the Local Group, which spans about 10 million light-years and contains several dozen galaxies. The Local Group, in turn, is part of the Virgo Supercluster, which spans just over 100 million light-years and is thought to contain at least 100 galaxy groups and clusters. [The work] is part of a study by a team of astronomers from Maryland, Hawaii, Israel, and France. They say it’s the most detailed map ever of the orbits of galaxies in our extended local neighborhood. It shows the past motions of some 1,400 galaxies within 100 million light-years of our Milky Way.

    Local Group. Andrew Z. Colvin 3 March 2011

    Virgo Supercluster, Wikipedia

    The Virgo Cluster alone – which is about 50 million light-years from us, or in the midst of the Virgo Supercluster’s 100 million light-years – has 600 trillion times the mass of our sun. These astronomers explained in their statement that the Virgo Cluster is pulling other galaxies toward itself, and absorbing them:

    Over a thousand galaxies have already fallen into the Virgo Cluster, while in the future all galaxies that are currently within 40 million light-years of the cluster will be captured. Our Milky Way galaxy lies just outside this capture zone. However the Milky Way and Andromeda galaxies, each with 2 trillion times the mass of the sun, are destined to collide and merge [with each other] in 5 billion years.

    3
    This series of photo illustrations shows the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy. Via NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas, and A. Mellinger

    The study [The Astrophysical Journal] [is] based on the measurement of 18,000 galaxy distances. The astronomers’ statement explained the interactive this way:

    “With the interactive model [in the full aticle], a viewer can pan, zoom, rotate, and pause/activate the time evolution of movement along orbits. The orbits are shown in a reference frame that removes the overall expansion of the universe.”

    The lead author of this study is Ed Shaya of the University of Maryland in collaboration with Brent Tully of University of Hawaii, Yehuda Hoffman of Hebrew University in Israel, and Daniel Pomarede of University of Paris-Saclay in France. These scientists used what they said is a novel method for determining galaxy orbits, which they called numerical action. Brent Tully said:

    “For the first time, we are not only visualizing the detailed structure of our Local Supercluster of galaxies but we are seeing how the structure developed over the history of the universe. An analogy is the study of the current geography of the Earth from the movement of plate tectonics.”

    The astronomers’ statement also explained:

    “These dramatic merger events are only part of a larger show. There are two overarching flow patterns within this volume of the universe. All galaxies in one hemisphere of the region – including our own Milky Way – are streaming toward a single flat sheet. In addition, essentially every galaxy over the whole volume is flowing, as a leaf would in a river, toward gravitational attractors at far greater distances …”

    Representations of the orbits in the Virgo Supercluster can also be seen in the video [in the full article]:

    Bottom line: A team of astronomers has made the most detailed map ever of the orbits of galaxies in our local supercluster. It shows the past motions of some 1,400 galaxies within 100 million light-years of our Milky Way.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 10:03 am on November 13, 2017 Permalink | Reply
    Tags: , , , , EarthSky, Moving shadows around a planet-forming star   

    From EarthSky: “Moving shadows around a planet-forming star” 

    1

    EarthSky

    November 13, 2017
    Deborah Byrd

    This star has a spiral disk of dust around it. Processes in the inner disk – winds, or swirls or clashes of pebbles – seem to be casting shadows on the outer disk.

    1
    Dust disk around the star HD 135344B. The star itself is removed from the picture. Image via Tomas Stolker/ astronomie.nl

    A team of mainly Dutch astronomers said on November 9, 2017 that it has observed moving shadows on a dust disk around a young star designated HD135344B. The star is 450 light-years away. It’s in a formation stage and shows striking spiral arms. On multiple days, the astronomers captured an image of this star and its dust disk. They used the SPHERE instrument on the Very Large Telescope in Chile, which can block the image of a central star in order to capture orbiting exoplanets or the details of dust disks like this one, with the goal of learning more about star formation.

    ESO SPHERE extreme adaptive optics system and coronagraphic facility on the extreme adaptive optics system and coronagraphic facility on the VLT, Cerro Paranal, Chile, with an elevation of 2,635 metres (8,645 ft) above sea level

    ESO/VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

    These astronomers believe that processes in the inner disk cast their shadows at the outer disk.

    The astronomers published their findings November 9 in the peer-reviewed The Astrophysical Journal. Their statement explained:

    “The discovery builds on an earlier publication in which the researchers made one image of the disk. By making multiple images, the astronomers clearly saw variations in the shadows. As a result, they could study the shadows in more detail …”

    The astronomers saw subtle variations of brightness in the outer dust disk. They presume this is because the gas and dust in the inner disk quickly turn around the star. The astronomers do not know yet which process causes the quick turning of the dust.”

    Astronomer Tomas Stolker is the first author of the paper about the shadows. He said the turning of the dust may be due to:

    “… winds, or swirls or clashes of pebbles.”

    The astronomers expect 1 or more large exoplanets – Jupiter-like worlds – to emerge from this dust disk eventually. Read more about this research from Astronomie.nl.

    Bottom line: For several days, astronomers imaged the young star HD 135344B and its dust disk. They saw moving shadows on the disk, which they believe is caused by a turning of the gas and dust in the star’s inner disk. Hence we learn more about the process by which stars and planets form.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 8:21 am on November 2, 2017 Permalink | Reply
    Tags: , , EarthSky, Twin Yellowstone super-eruptions altered global climate, Volcano science   

    From EarthSky: “Twin Yellowstone super-eruptions altered global climate” 

    1

    EarthSky

    November 2, 2017
    Eleanor Imster

    The Yellowstone supervolcano’s last eruption wasn’t a single event, but 2 closely-spaced eruptions that put the brakes on a natural global-warming trend, says a study.

    1
    The gorgeous colors of Yellowstone National Park’s Grand Prismatic hot spring are among the park’s myriad hydrothermal features created by the fact that Yellowstone is a supervolcano – the largest type of volcano on Earth. Photo via Windows into the Earth by Robert B. Smith and Lee J. Siegel

    The Yellowstone supervolcano’s last catastrophic eruption, about 630,000 years ago, was not a single event, but two powerful and closely-spaced eruptions, according to a new study. The super-eruptions were powerful enough, the researchers say, to slow a natural global warming trend that eventually led the planet out of a major ice age.

    For the study, presented at the Geological Society of American’s annual meeting in Seattle on October 25, 2017, a team of geologists from the University of California Santa Barbara (UCSB) analyzed two layers of volcanic ash discovered in seafloor sediments off the coast of Southern California. These layers of ash, sandwiched among sediments, bear the unique chemical fingerprint of Yellowstone’s most recent super eruption. and contain a remarkably detailed climate record of the violent events that formed the vast Yellowstone caldera – or cauldron-like crater – that we see today.
    UCSB geologist Jim Kennett said in a statement:

    “We discovered here that there are two ash-forming super eruptions 170 years apart, and each cooled the ocean by about three degrees Celsius.”

    Read more about the research here.

    By comparing the volcanic ash record with the climate record of single-celled marine animal fossils, it’s quite clear, Kennet said, that both of these eruptions caused separate volcanic winters, when ash and volcanic sulfur dioxide emissions reduce the amount of sunlight reaching Earth’s surface and cause temporary cooling. According to the study, the onset of the global cooling events was abrupt and coincided precisely with the timing of the supervolcanic eruptions.

    These cooling events occurred at an especially sensitive time, Kennet said, when the global climate was warming out of an ice age and easily disrupted by such events. But, Kennet added, each time, the cooling lasted longer than it should have, according to simple climate models. He said:

    “We see planetary cooling of sufficient magnitude and duration that there had to be other feedbacks involved.”

    These feedbacks might include increased sunlight-reflecting sea ice and snow cover or a change in ocean circulation that would cool the planet for a longer time.

    Bottom line: New research suggest that the Yellowstone supervolcano’s last eruption wasn’t a single event, but 2 closely-spaced eruptions that slowed a natural global-warming trend.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
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