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  • richardmitnick 12:51 pm on January 31, 2017 Permalink | Reply
    Tags: , , , , Gamma rays from solar storms, , Solar research   

    From Fermi: “NASA’s Fermi Sees Gamma Rays from ‘Hidden’ Solar Flares” 

    NASA Fermi Banner


    Fermi

    Jan. 30, 2017
    Francis Reddy
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    An international science team says NASA’s Fermi Gamma-ray Space Telescope has observed high-energy light from solar eruptions located on the far side of the sun, which should block direct light from these events. This apparent paradox is providing solar scientists with a unique tool for exploring how charged particles are accelerated to nearly the speed of light and move across the sun during solar flares.

    “Fermi is seeing gamma rays from the side of the sun we’re facing, but the emission is produced by streams of particles blasted out of solar flares on the far side of the sun,” said Nicola Omodei, a researcher at Stanford University in California. “These particles must travel some 300,000 miles within about five minutes of the eruption to produce this light.”

    Omodei presented the findings on Monday, Jan. 30, at the American Physical Society meeting in Washington, and a paper describing the results will be published online in The Astrophysical Journal on Jan. 31.


    Access mp4 video here .
    On three occasions, NASA’s Fermi Gamma-ray Space Telescope has detected gamma rays from solar storms on the far side of the sun, emission the Earth-orbiting satellite shouldn’t be able to detect. Particles accelerated by these eruptions somehow reach around to produce a gamma-ray glow on the side of the sun facing Earth and Fermi. Watch to learn more. Credits: NASA’s Goddard Space Flight Center/Scott Wiessinger, producer

    Fermi has doubled the number of these rare events, called behind-the-limb flares, since it began scanning the sky in 2008. Its Large Area Telescope (LAT) has captured gamma rays with energies reaching 3 billion electron volts, some 30 times greater than the most energetic light previously associated with these “hidden” flares.

    NASA/Fermi LAT
    NASA/Fermi LAT

    Thanks to NASA’s Solar Terrestrial Relations Observatory (STEREO) spacecraft, which were monitoring the solar far side when the eruptions occurred, the Fermi events mark the first time scientists have direct imaging of beyond-the-limb solar flares associated with high-energy gamma rays.

    NASA/STEREO spacecraft
    NASA/STEREO spacecraft

    3
    These solar flares were imaged in extreme ultraviolet light by NASA’s STEREO satellites, which at the time were viewing the side of the sun facing away from Earth. All three events launched fast coronal mass ejections (CMEs). Although NASA’s Fermi Gamma-ray Space Telescope couldn’t see the eruptions directly, it detected high-energy gamma rays from all of them. Scientists think particles accelerated by the CMEs rained onto the Earth-facing side of the sun and produced the gamma rays. The central image was returned by the STEREO A spacecraft, all others are from STEREO B.
    Credits: NASA/STEREO

    4
    Combined images from NASA’s Solar Dynamics Observatory (center) and the NASA/ESA Solar and Heliospheric Observatory (red and blue) show an impressive coronal mass ejection departing the far side of the sun on Sept. 1, 2014. This massive cloud raced away at about 5 million mph and likely accelerated particles that later produced gamma rays Fermi detected. Credits: NASA/SDO and NASA/ESA/SOHO

    NASA/SDO
    NASA/SDO

    ESA/NASA SOHO
    ESA/NASA SOHO

    “Observations by Fermi’s LAT continue to have a significant impact on the solar physics community in their own right, but the addition of STEREO observations provides extremely valuable information of how they mesh with the big picture of solar activity,” said Melissa Pesce-Rollins, a researcher at the National Institute of Nuclear Physics in Pisa, Italy, and a co-author of the paper.

    The hidden flares occurred Oct. 11, 2013, and Jan. 6 and Sept. 1, 2014. All three events were associated with fast coronal mass ejections (CMEs), where billion-ton clouds of solar plasma were launched into space. The CME from the most recent event was moving at nearly 5 million miles an hour as it left the sun. Researchers suspect particles accelerated at the leading edge of the CMEs were responsible for the gamma-ray emission.

    Large magnetic field structures can connect the acceleration site with distant part of the solar surface. Because charged particles must remain attached to magnetic field lines, the research team thinks particles accelerated at the CME traveled to the sun’s visible side along magnetic field lines connecting both locations. As the particles impacted the surface, they generated gamma-ray emission through a variety of processes. One prominent mechanism is thought to be proton collisions that result in a particle called a pion, which quickly decays into gamma rays.

    In its first eight years, Fermi has detected high-energy emission from more than 40 solar flares. More than half of these are ranked as moderate, or M class, events. In 2012, Fermi caught the highest-energy emission ever detected from the sun during a powerful X-class flare, from which the LAT detected high­energy gamma rays for more than 20 record-setting hours.

    NASA’s Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy and with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

    For more information on Fermi, visit:

    https://www.nasa.gov/fermi

    See the full article here .

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    NASA’s Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy and with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

     
  • richardmitnick 2:02 pm on December 16, 2016 Permalink | Reply
    Tags: , Solar research, Watch Out for Falling Plasma   

    From AAS NOVA: “Watch Out for Falling Plasma” 

    AASNOVA

    American Astronomical Society

    16 December 2016
    Susanna Kohler

    1
    The crosses in this SDO/AIA image mark the path taken by plasma that erupted from the Sun in a flare in June 2011 and then fell back down to the Sun’s surface. Such events can tell us about the local solar magnetic field and how it interacts with the plasma. [Petralia et al. 2016]

    Sometimes plasma emitted from the Sun doesn’t escape into space, but instead comes crashing back down to the solar surface. What can observations and models of this process tell us about how the plasma falls and the local conditions on the Sun?

    Fallback from a Flare

    On 7 June 2011, an M-class flare erupted from the solar surface. As the Solar Dynamics Observatory’s Atmospheric Imaging Assembly looked on, plasma fragments from the flare arced away from the Sun and then fell back to the surface.

    NASA/SDO
    NASA/SDO

    Some fragments fell back where the Sun’s magnetic field was weak, returning directly to the surface. But others fell within active regions, where they crashed into the Sun’s magnetic field lines, brightening the channels and funneling along them through the dense corona and back to the Sun’s surface.

    2
    The authors’ model of the falling blobs at several different times in their simulation. The blobs get disrupted when they encounter the field lines, and are then funneled along the channels to the solar surface. [Adapted from Petralia et al. 2016]

    This sort of flare and fall-back event is a common occurrence with the Sun, and SDO’s observations of the June 2011 event present an excellent opportunity to understand the process better. A team of scientists led by Antonino Petralia (University of Palermo, Italy and INAF-OAPA) modeled this event in an effort to learn more about how the falling plasma interacts with strong magnetic fields above the solar surface.

    Magnetic Fields as Guides

    Petralia and collaborators used three-dimensional magnetohydrodynamical modeling to attempt to reproduce the observations of this event. They simulated blobs of plasma as they fall back to the solar surface and interact with magnetic field lines over a range of different conditions.

    The team found that only simulations that assume a relatively strong magnetic field resulted in the blobs funneling along a channel to the Sun’s surface; with weaker fields the blobs to simply broke through the field lines.

    The observations were best reproduced by downfall channeled in a million-Kelvin coronal loop confined by a magnetic field of ~10–20 Gauss. In this scenario, a falling fragment is deviated from its path by the field and disrupted. It’s then channeled along the magnetic flux tube, driving a shock and heating in the tube ahead of it — which, the authors find, is the cause the observed brightening that occurs ahead of the actual plasma passage.

    Petralia and collaborators point out that this new mechanism for brightening downflows channeled by the magnetic field is applicable not only in our Sun, but also in young, accreting stars. Events like these can therefore work as probes of the ambient atmosphere of such stars, providing information about the local plasma density and magnetic field.

    Citation

    A. Petralia et al 2016 ApJ 832 2. doi:10.3847/0004-637X/832/1/2

    See the full article here .

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  • richardmitnick 9:37 pm on December 15, 2016 Permalink | Reply
    Tags: Solar research,   

    From Institute for Astronomy U Hawaii Manoa- “Giving the Sun a brake: Astronomers solve puzzle of slowing rotation” 

    U Hawaii

    University of Hawaii

    U Hawaii 2.2 meter telescope, Mauna Kea, Hawaii, USA
    U Hawaii 2.2 meter telescope, Mauna Kea, Hawaii, USA

    IFA at Manua Kea

    Dec 12, 2016
    Jeff Kuhn
    kuhn@ifa.hawaii.edu
    (808) 573-9517
    Astronomer, Institute for Astronomy

    Roy Gal
    roygal@hawaii.edu
    (808) 956-6235
    Associate Specialist, Institute for Astronomy

    1
    An image of the Sun taken with The Helioseismic and Magnetic Imager (HMI) on the Solar Dynamics Observatory spacecraft. NASA photo.

    NASA/SDO
    NASA/SDO

    Astronomers from the University of Hawaiʻi’s Institute for Astronomy (IfA), as well as Brazil and Stanford University, may have solved a long-standing solar mystery. Two decades ago, scientists discovered that the outer five percent of the Sun spins more slowly than the rest of its interior. Now, in a new study, to be published in the journal Physical Review Letters, IfA Maui scientists Ian Cunnyngham, Jeff Kuhn and Isabelle Scholl, together with Marcelo Emilio (Brazil) and Rock Bush (Stanford), describe the physical mechanism responsible for slowing the Sun’s outer layers.

    Said team leader Jeff Kuhn, “The Sun won’t stop spinning anytime soon, but we’ve discovered that the same solar radiation that heats the Earth is ‘braking’ the Sun because of Einstein’s Special Relativity, causing it to gradually slow down starting from its surface.”

    The Sun rotates on its axis at an average rate of about once per month but that rotation isn’t like, for example, the solid Earth or a spinning disk because the rate varies with solar latitude and distance from the center of the Sun.

    The team used several years of data from NASA’s Solar Dynamics Observatory and the Helioseismic and Magnetic Imager satellite to measure a sharp down-turn in the Sun’s rotation rate in its very outer 150km. Said Kuhn, “This is a gentle torque that is slowing it down, but over the Sun’s 5 billion year lifetime it has had a very noticeable influence on its outer 35,000km.” Their paper describes how this “photon-braking effect” should be at work in most stars.

    This change in rotation at the Sun’s surface affects the large-scale solar magnetic field and researchers are now trying to understand how the solar magnetism that extends out into the corona and finally into the Earth’s environment will be affected by this braking.

    The research will appear in the January issue of Physical Review Letters, and is available online at https://arxiv.org/abs/1612.00873.

    See the full article here .

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    System Overview

    The University of Hawai‘i System includes 10 campuses and dozens of educational, training and research centers across the Hawaiian Islands. As the public system of higher education in Hawai‘i, UH offers opportunities as unique and diverse as our Island home.

    The 10 UH campuses and educational centers on six Hawaiian Islands provide unique opportunities for both learning and recreation.

    UH is the State’s leading engine for economic growth and diversification, stimulating the local economy with jobs, research and skilled workers.

     
  • richardmitnick 7:52 am on November 5, 2016 Permalink | Reply
    Tags: , , , Solar research   

    From Caltech: “Realistic Solar Corona Loops Simulated in Lab” 

    Caltech Logo
    Caltech

    11/04/2016

    Robert Perkins
    (626) 395-1862
    rperkins@caltech.edu

    1
    Side-by-side: A real coronal loop (left) compared to one simulated in Paul Bellan’s lab (right).
    Credit: Courtesy of P. Bellan/Caltech

    Caltech applied physicists have experimentally simulated the sun’s magnetic fields to create a realistic coronal loop in a lab.

    Coronal loops are arches of plasma that erupt from the surface of the sun following along magnetic field lines. Because plasma is an ionized gas—that is, a gas of free-flowing electrons and ions—it is an excellent conductor of electricity. As such, solar corona loops are guided and shaped by the sun’s magnetic field.

    The earth’s magnetic field acts as a shield that protects humans from the strong X-rays and energized particles emitted by the eruptions, but communications satellites orbit outside this shield field and therefore remain vulnerable. In March 1989, a particularly large flare unleashed a blast of charged particles that temporarily knocked out one of the National Oceanic and Atmospheric Administration’s geostationary operational environmental satellites that monitor the earth’s weather; caused a sensor problem on the space shuttle Discovery; and tripped circuit breakers on Hydro-Québec’s power grid, which blacked out the province of Quebec in Ontario, Canada, for nine hours.

    “This potential for causing havoc—which only increases the more humanity relies on satellites for communications, weather forecasting, and keeping track of resources—makes understanding how these solar events work critically important,” says Paul Bellan, professor of applied physics in the Division of Engineering and Applied Science.

    Although simulated coronal loops have been created in labs before, this latest attempt incorporated a magnetic strapping field that binds the loop to the sun’s surface. Think of a strapping field like the metal hoops on the outside of a wooden barrel. While the slats of the barrel are continually under pressure pushing outward, the metal hoops sit perpendicularly to the slats and hold the barrel together.

    The strength of this strapping field diminishes with distance from the sun. This means that when close to the solar surface, the loops are clamped down tightly by the strapping field but then can break loose and blast away if they rise to a certain altitude where the strapping field is weaker. These eruptions are known as solar flares and coronal mass ejections (CMEs).

    CMEs are rope-like discharges of hot plasma that accelerate away from the sun’s surface at speeds of more than a million miles per hour. These eruptions are capable of releasing energy equivalent to 1 billion megatons of TNT, making them potentially the most powerful explosions in the solar system. (CMEs are not to be confused with solar flares, which often occur as part of the same event. Solar flares are bursts of light and energy, while CMEs are blasts of particles embedded in a magnetic field.)

    The simulated loops and strapping fields provide new insight into how energy is stored in the solar corona and then released suddenly. Bellan worked with Caltech graduate student Bao Ha (MS ’10, PhD ’16) to create the strapping field and coronal loop. The results of their experiments were published in the journal Geophysical Research Letters on September 17, 2016.

    Bellan and his colleagues have been working on laboratory-scale simulations of solar corona phenomena for two decades. In the lab, the team generates ropes of plasma in a 1.5-meter-long vacuum chamber.

    “Studying coronal mass ejections is challenging, since humans do not know how and when the sun will erupt. But laboratory experiments permit the control of eruption parameters and enable the systematic explorations of eruption dynamics,” says Ha, lead author of the GRL paper. “While experiments with the same eruption parameters are easily reproducible, the loop dynamics vary depending on the configuration of the strapping magnetic field.”

    Simulating a strapping field with strength that fades over the relatively short length of the vacuum chamber proved difficult, Bellan says. In order to make it work, Ha and Bellan had to engineer electromagnetic coils that produce the strapping field inside the chamber itself.

    After more than three years of design, fabrication, and testing, Bellan and Ha were able to create a strapping field that peaks in strength about 10 centimeters away from where the plasma loop forms, then dies off a short distance farther down the vacuum chamber.

    The arrangement allows Bellan and Ha to watch the plasma loop slowly grow in size, then reach a critical point and fire off to the far end of the chamber.

    Next, Bellan plans to measure the magnetic field inside the erupting loop and also study the waves that are emitted when plasmas break apart.

    Their paper, titled Laboratory demonstration of slow rise to fast acceleration of arched magnetic flux ropes, is available online at http://onlinelibrary.wiley.com/doi/10.1002/2016GL069744/full. The research was supported by the National Science Foundation, the Air Force Office of Scientific Research, and the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences.

    See the full article here .

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    Caltech campus
    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

     
  • richardmitnick 7:28 am on October 18, 2016 Permalink | Reply
    Tags: , , , Solar research   

    From Goddard: “Wayward Field Lines Challenge Solar Radiation Models” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Oct. 17, 2016
    Lina Tran
    kathalina.k.tran@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    In addition to the constant emission of warmth and light, our sun sends out occasional bursts of solar radiation that propel high-energy particles toward Earth. These solar energetic particles, or SEPs, can impact astronauts or satellites. To fully understand these particles, scientists must look to their source: the bursts of solar radiation.

    But scientists aren’t exactly sure which of the two main features of solar eruptions –narrow solar flares or wide coronal mass ejections – causes the SEPs during different bursts. Scientists try to distinguish between the two possibilities by using observations, and computer models based on those observations, to map out where the particles could be found as they spread out and traveled away from the sun. NASA missions STEREO and SOHO collect the data upon which these models are built.

    NASA/STEREO spacecraft
    NASA/STEREO spacecraft

    ESA/NASA SOHO
    ESA/NASA SOHO

    Sometimes, these solar observatories saw SEPs on the opposite side of the sun than where the eruption took place. What kind of explosion on the sun could send the particles so far they ended up behind where they started?


    Access mp4 video here .
    This video compares the two models for particle distribution over the course of just three hours after an SEP event. The white line represents a magnetic field line, the general path that the SEPs follow. The line starts at an SEP event at the sun, and leads the particles in a spiral around the sun. The animation of the updated model, on the right, depicts a static field line, but as the SEPs travel farther in space, turbulent solar material causes wandering field lines. In turn, wandering field lines cause the particles to spread much more efficiently than the traditional model, on the left, predicted. Credits: NASA’s Goddard Space Flight Center/UCLan/Stanford/ULB/Joy Ng, producer

    Now a new model has been developed by an international team of scientists, led by the University of Central Lancashire and funded in part by NASA. The new model shows how particles could travel to the back of the sun no matter what type of event first propelled them. Previous models assumed the particles mainly follow the average of magnetic field lines in space on their way from the sun to Earth, and slowly spread across the average over time. The average field line forms a steady path following a distinct spiral because of the sun’s rotation. But the new model takes into consideration that magnetic fields lines can wander – a result of turbulence in solar material as it travels away from the sun.

    With this added information, models now show SEPs spiraling out much wider and farther than previous models predicted – explaining how SEPs find their way to even the far side of the sun. Understanding the nature of SEP distribution helps scientists as they continue to map out the origins of these high-energy particles. A paper published in Astronomy and Astrophysics on June 6, 2016, summarizes the research, a result of collaboration between the University of Central Lancashire, Université Libre de Bruxelles, University of Waikato and Stanford University.

    See the full article here .

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    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.
    NASA Goddard campus
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 5:32 pm on May 23, 2016 Permalink | Reply
    Tags: , , , Solar research   

    From Goddard: “NASA: Solar Storms May Have Been Key to Life on Earth” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    May 23, 2016
    Karen C. Fox
    NASA’s Goddard Space Flight Center, Greenbelt, Md.
    karen.c.fox@nasa.gov

    Solar eruption 2012 by NASA's Solar Dynamic Observatory SDO
    Solar eruption 2012 by NASA’s Solar Dynamic Observatory SDO

    Our sun’s adolescence was stormy—and new evidence shows that these tempests may have been just the key to seeding life as we know it.

    Some 4 billion years ago, the sun shone with only about three-quarters the brightness we see today, but its surface roiled with giant eruptions spewing enormous amounts of solar material and radiation out into space. These powerful solar explosions may have provided the crucial energy needed to warm Earth, despite the sun’s faintness. The eruptions also may have furnished the energy needed to turn simple molecules into the complex molecules such as RNA and DNA that were necessary for life. The research was published* in Nature Geoscience on May 23, 2016, by a team of scientists from NASA.


    Access mp4 video here .

    Understanding what conditions were necessary for life on our planet helps us both trace the origins of life on Earth and guide the search for life on other planets. Until now, however, fully mapping Earth’s evolution has been hindered by the simple fact that the young sun wasn’t luminous enough to warm Earth.

    “Back then, Earth received only about 70 percent of the energy from the sun than it does today,” said Vladimir Airapetian, lead author of the paper and a solar scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “That means Earth should have been an icy ball. Instead, geological evidence says it was a warm globe with liquid water. We call this the Faint Young Sun Paradox. Our new research shows that solar storms could have been central to warming Earth.”

    Scientists are able to piece together the history of the sun by searching for similar stars in our galaxy. By placing these sun-like stars in order according to their age, the stars appear as a functional timeline of how our own sun evolved. It is from this kind of data that scientists know the sun was fainter 4 billion years ago. Such studies also show that young stars frequently produce powerful flares – giant bursts of light and radiation — similar to the flares we see on our own sun today. Such flares are often accompanied by huge clouds of solar material, called coronal mass ejections, or CMEs, which erupt out into space.

    NASA’s Kepler mission found stars that resemble our sun about a few million years after its birth.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    The Kepler data showed many examples of what are called “superflares” – enormous explosions so rare today that we only experience them once every 100 years or so. Yet the Kepler data also show these youngsters producing as many as ten superflares a day.

    While our sun still produces flares and CMEs, they are not so frequent or intense.

    What’s more, Earth today has a strong magnetic field that helps keep the bulk of the energy from such space weather from reaching Earth.

    Magnetosphere of Earth, original bitmap from NASA. SVG rendering by Aaron Kaase
    Magnetosphere of Earth, original bitmap from NASA

    Space weather can, however, significantly disturb a magnetic bubble around our planet, the magnetosphere, a phenomenon referred to as geomagnetic storms that can affect radio communications and our satellites in space. It also creates auroras – most often in a narrow region near the poles where Earth’s magnetic fields bow down to touch the planet.

    Our young Earth, however, had a weaker magnetic field, with a much wider footprint near the poles.

    “Our calculations show that you would have regularly seen auroras all the way down in South Carolina,” says Airapetian. “And as the particles from the space weather traveled down the magnetic field lines, they would have slammed into abundant nitrogen molecules in the atmosphere. Changing the atmosphere’s chemistry turns out to have made all the difference for life on Earth.”

    The atmosphere of early Earth was also different than it is now: Molecular nitrogen – that is, two nitrogen atoms bound together into a molecule – made up 90 percent of the atmosphere, compared to only 78 percent today. As energetic particles slammed into these nitrogen molecules, the impact broke them up into individual nitrogen atoms. They, in turn, collided with carbon dioxide, separating those molecules into carbon monoxide and oxygen.

    The free-floating nitrogen and oxygen combined into nitrous oxide, which is a powerful greenhouse gas. When it comes to warming the atmosphere, nitrous oxide is some 300 times more powerful than carbon dioxide. The teams’ calculations show that if the early atmosphere housed less than one percent as much nitrous oxide as it did carbon dioxide, it would warm the planet enough for liquid water to exist.

    This newly discovered constant influx of solar particles to early Earth may have done more than just warm the atmosphere, it may also have provided the energy needed to make complex chemicals. In a planet scattered evenly with simple molecules, it takes a huge amount of incoming energy to create the complex molecules such as RNA and DNA that eventually seeded life.

    While enough energy appears to be hugely important for a growing planet, too much would also be an issue — a constant chain of solar eruptions producing showers of particle radiation can be quite detrimental. Such an onslaught of magnetic clouds can rip off a planet’s atmosphere if the magnetosphere is too weak. Understanding these kinds of balances help scientists determine what kinds of stars and what kinds of planets could be hospitable for life.

    “We want to gather all this information together, how close a planet is to the star, how energetic the star is, how strong the planet’s magnetosphere is in order to help search for habitable planets around stars near our own and throughout the galaxy,” said William Danchi, principal investigator of the project at Goddard and a co-author on the paper. “This work includes scientists from many fields — those who study the sun, the stars, the planets, chemistry and biology. Working together we can create a robust description of what the early days of our home planet looked like – and where life might exist elsewhere.”

    For more information about the Kepler mission, visit:

    http://www.nasa.gov/kepler

    *Science paper:
    Prebiotic chemistry and atmospheric warming of early Earth by an active young Sun

    See the full article here.

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    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard Campus
    NASA/Goddard Campus
    NASA

     
  • richardmitnick 5:04 pm on March 30, 2016 Permalink | Reply
    Tags: , , , Solar research   

    From Eos: “Toward an Understanding of Earth-Affecting Solar Eruptions” 

    Eos news bloc

    Eos

    3.30.16
    Yuming Wang
    ymwang@ustc.edu.cn

    Solar eruption 2012 by NASA's Solar Dynamic Observatory SDO
    Solar eruption 2012 by NASA’s Solar Dynamic Observatory SDO

    Solar eruptions are frequently occurring phenomena on the Sun where large-scale magnetized bubbles and large amounts of electromagnetic radiation and energetic particles spread into space. The radiation and masses that solar eruptions release have potential impacts on Earth so it’s been an important area of study in the space physics and space weather communities. Flares are one kind of solar eruption and have been studied for hundreds of years; before the 1990s, they were believed to be the major driving sources of the disturbances in space. As observational technology improved, scientists began to realize that another kind of solar eruption—coronal mass ejections (CMEs), which accompany flares—play a more important role in producing the disturbances that could negatively affect Earth.

    One of the most important motivations to study solar eruptions is their application to space weather forecasting. Flares are a relatively small-scale phenomenon on the Sun and affect the Earth mostly through electromagnetic emissions and energetic particles. Flares exhibit fairly predictable behavior, so it’s relatively easy to anticipate the effect they are going to have on the Earth and our systems: their electromagnetic radiations travel radially at light speed and energetic particles propagate roughly along the spiral interplanetary magnetic field lines at a relativistic speed and don’t spread out too much in space and time. However, CMEs are harder to predict. They affect the Earth through transient magnetized bubbles and associated shocks and energetic particles. They can travel with a wide range of speed from 100 to more than 3000 kilometers per second. Such a wide spectrum could appear in many other properties of CMEs, like strength, size, orientation and propagation direction. Moreover, during their journey through space, these properties can be altered by ambient solar wind. Thus, the effect they have on Earth and our systems becomes much more intricate to be forecast than that of flares.

    There are lots of questions to be answered in predicting the significance of the effects that CMEs could have on Earth. The primary questions, in logical order, are: Will the CME hit the Earth? When will the CME hit the Earth? Will it trigger a geomagnetic storm and what will the size of the storm be? Will it initiate a solar energetic particle (SEP) event, manifesting a significant enhancement of the flux of energetic particles, and how strong might that SEP event be?

    Even for the first question, the answer is not straightforward. A good example is the fast CME on 15 March 2015 which produced so far the largest geomagnetic storms in the 24th solar cycle. However, the Space Weather Prediction Center initially forecasted it as a much smaller event because the CME seemed not to have been propagating toward the Earth. This surprising event has attracted the attention of space physics and space weather communities. Some analyses suggest that the interaction of the CME with the corona and ambient solar wind increased the chance of the CME to produce the major geomagnetic storm [Kataoka et al., 2015 and other works, e.g., by Wood B. E. et al. and Wang Y. et al., both under consideration by a AGU journal].

    As one of four projects under the SCOSTEP (Scientific Committee on Solar-Terrestrial Physics) program Variability of the Sun and Its Terrestrial Impact (VarSITI), International Study of Earth-affecting Solar Transients (ISEST) is devoted to solving these puzzles. The Solar TErrestrial RElations Observatory (STEREO) mission launched in 2006 largely inspired the relevant research with its unprecedented imaging data of the interplanetary medium.

    NASA/STEREO spacecraft
    NASA/STEREO spacecraft

    The upcoming space missions Solar Orbiter and Solar Probe Plus, which are scheduled to be launched in 2017 and 2018 respectively, will take a much closer look at the Sun and sample the solar wind plasma.

    ESA/Solar Orbiter
    ESA/Solar Orbiter

    NASA/SPP Solar Probe Plus
    NASA/SPP Solar Probe Plus

    These new and exciting data will undoubtedly advance our understanding in the Earth-affecting solar eruptions in the near future.

    See the full article here .

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    Eos is the leading source for trustworthy news and perspectives about the Earth and space sciences and their impact. Its namesake is Eos, the Greek goddess of the dawn, who represents the light shed on understanding our planet and its environment in space by the Earth and space sciences.

     
  • richardmitnick 7:01 am on March 21, 2016 Permalink | Reply
    Tags: , , , Solar research   

    From ESA: “Ultraviolet image shows the Sun’s intricate atmosphere” 

    ESA Space For Europe Banner

    European Space Agency

    21/03/2016
    SOHO (ESA & NASA)

    1

    This eerie coloured orb is nothing less than the life-giver of the Solar System. It is the Sun, the prodigious nuclear reactor that sits at the heart of our planetary system and supplies our world with all the light and heat needed for us to exist.

    To the human eye, the Sun is a burning light in the sky. It is dangerous to look at it directly unless some special filtering is used to cut out most of the light pouring from its incandescent surface.

    However, to the electronic eyes of the Solar and Heliospheric Observatory (SOHO), the Sun appears a place of delicate beauty and detail.

    ESA/SOHO
    ESA/SOHO

    SOHO’s extreme-ultraviolet telescope was used to take these images. This telescope is sensitive to four wavelengths of extreme-ultraviolet light, and the three shortest were used to build this image. Each wavelength has been colour-coded to highlight the different temperatures of gas in the Sun.

    The gas temperature is traced by iron atoms, where rising temperature strips increasing numbers of electrons from around the nucleus.

    An iron atom usually contains 26 electrons. In this image, blue shows iron at a temperature of 1 million degrees celsius, having lost 8 or 9 electrons. Yellow shows iron at 1.5 million degrees (11 lost electrons) and red shows iron at 2.5 million degrees (14 lost electrons).

    These atoms all exist in the outer part of the Sun’s atmosphere known as the corona. How the corona is heated to millions of degrees remains the subject of scientific debate.

    The constant monitoring of the Sun’s atmosphere with SOHO, and with other Sun-staring spacecraft like the Solar Dynamics Observatory and Proba-2, is allowing solar physicists to build up a detailed picture of the way the corona behaves.

    NASA/SDO
    NASA/SDO

    ESA/Proba-2
    ESA/Proba-2

    This gives them insight into the physical processes that give rise to the corona and its behaviour.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 8:31 am on December 12, 2015 Permalink | Reply
    Tags: , , , Solar research,   

    From U Arizona: “UA Completes Primary Mirror for Advanced Solar Telescope” 

    U Arizona bloc

    University of Arizona

    December 11, 2015
    Justin Walker
    UA College of Optical Sciences
    520-621-0207
    jwalker@optics.arizona.edu

    1
    The completed primary mirror for the Daniel K. Inouye Solar Telescope awaits shipping at the College of Optical Sciences.

    The Daniel K. Inouye Solar Telescope, or DKIST, is scheduled to see first light in 2019 on the island of Maui.

    Completion of the $14 million primary mirror for the 4.2-meter Daniel K. Inouye Solar Telescope, which is scheduled to see first light in 2019, was celebrated this week by the College of Optical Sciences at the University of Arizona.

    DKIST telescope
    View of DKIST

    The telescope is under construction by the National Solar Observatory atop the Haleakala volcano on the Pacific island of Maui. It is named after the late Daniel K. Inouye, who was a U.S. senator from Hawaii.

    The telescope, also known as DKIST, features an off-axis, clear aperture design to allow for observations with unprecedented spatial, spectral and temporal resolution.

    “We’re actually going to point this at the sun,” said Thomas Rimmele, DKIST’s project director, who was on hand for the mirror’s completion. “This is an important telescope. It will be transformational for understanding the sun, solar activity and its impacts on humankind.”

    The DKIST primary mirror blank was fabricated by Schott AG of Germany then shipped to the UA for polishing. The UA’s polishing effort was four years in the in the planning and execution, involving more than 50 people from the College of Optical Sciences and Steward Observatory. The polishing alone required an estimated 80 hours a week for six months, utilizing four new measurement techniques.

    “It was daunting to plan out the things we needed to do,” said Jim Burge, a UA professor of optical sciences and astronomy and the project’s principal investigator, citing the mirror’s complex shape and challenging specifications.

    As an example of the research involved, Burge said, eight UA students worked on their thesis or dissertation related to different aspects of the project.

    “Nobody has made a surface like this before,” Burge said. “Nobody has needed a surface like this before.”

    The mirror’s construction was “a research project all the way through,” said Joseph McMullin, DKIST’s project manager.

    The telescope’s site on Haleakala was selected for its clear daytime atmospheric seeing conditions, which will enable study of the solar corona. DKIST will be capable of observing objects on the sun that are about 25 kilometers (nearly 16 miles) across.

    Construction at the DKIST site began in January 2013. Work on the telescope’s housing was completed in September of that year.

    Justin Walker, associate dean of the College of Optical Sciences, praised the teamwork involved in the mirror project.

    “The University of Arizona is known for this kind of work in optical fabrication, which is unmatched by any other university,” Walker said. “We have this breadth of engineering staff that supports our faculty to do cutting-edge science with applied outcomes. It’s a unique capability.”

    See the full article here .

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    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 5:18 am on October 15, 2015 Permalink | Reply
    Tags: , , , , Solar research   

    From Goddard- “Comet Encke: A Solar Windsock Observed by NASA’s STEREO” 

    NASA Goddard Banner
    Goddard Space Flight Center

    Oct. 13, 2015
    Sarah Frazier
    NASA’s Goddard Space Flight Center

    1
    A visualization of the constant outflow of material from the sun, known as the solar wind. There is no consensus on what powers the solar wind’s acceleration, its extreme variability, or its remarkably high temperatures. Credits: ESA/NASA/SOHO

    Much like the flapping of a windsock displays the quick changes in wind’s speed and direction, called turbulence, comet tails can be used as probes of the solar wind – the constant flowing stream of material that leaves the sun in all directions. According to new studies of a comet tail observed by NASA’s Solar and Terrestrial Relations Observatory, or STEREO, the vacuum of interplanetary space is filled with turbulence and swirling vortices similar to gusts of wind on Earth. Such turbulence can help explain two of the wind’s most curious features: its variable nature and unexpectedly high temperatures. A paper on this work was published in The Astrophysical Journal on Oct. 13, 2015.

    NASA STEREO spacecraft
    STEREO

    “The solar wind at Earth is about 70 times hotter than one might expect from the temperature of the solar corona and how much it expands as it crosses the void,” said Craig DeForest, a solar physicist at the Southwest Research Institute in Boulder, Colorado, and lead author on the study. “The source of this extra heat has been a mystery of solar wind physics for several decades.”

    There is much that is conclusively known about the solar wind: It is made of a sea of electrically-charged electrons and ions and also carries the interplanetary magnetic field along for the ride, forging a magnetic connection between the sun and Earth and the other planets in the solar system. There is no consensus, however, on what powers the wind’s acceleration, especially when it is traveling at its fastest speeds. Complicating the search for such understanding are two of its most distinctive characteristics: The solar wind can be highly variable, meaning that measurements just short times or distances apart can yield quite different results. It is also very, very hot—remarkably so.

    The new study helped explain these characteristics using the heliospheric imager onboard STEREO. The scientists studied the movements of hundreds of dense chunks of glowing ionized gas within the ribbon of Comet Encke’s tail, which passed within STEREO’s field of view in 2007. Fluctuations in the solar wind are mirrored in what is seen in the tail, so by tracking these clumps, scientists were able to reconstruct the motion of the solar wind, catching an unprecedented look at the turbulence.

    Identifying this turbulence in the solar wind has the potential to solve the mystery of how the solar wind gets so hot. Based on the intensity of the turbulence researchers saw, they calculated that the energy available from turbulence is more than ten times what would be required to heat the solar wind to observed temperatures.

    What’s more, it also helps to solve the variability problem, which other theories have not yet done successfully.

    “This turbulent motion mixes up the solar wind, leading to the rapid variation that we see at Earth,” said DeForest.

    For years, scientists have taken direct measurements of the solar wind—known as in situ measurements, which are captured as the solar wind passes over one of the dozens of satellites carrying the appropriate instruments. Most of these satellites observe the sun from a vantage point similar to that of Earth. STEREO-A, however, orbits the sun in a slightly smaller and faster orbit than Earth, meaning it moves around the sun farther and farther from Earth over time. So, in addition to the images of Comet Encke as it streamed past in April 2007, STEREO-A also provides us with in situ solar wind measurements from a unique perspective.

    On the other hand, the solar wind is notoriously hard to study remotely—that is, with measurements from afar. Its particles flow at 250 miles per second, and they are so dispersed that interplanetary space at Earth’s orbit has about a thousand times fewer particles in one cubic inch of space than the best laboratory vacuum on Earth.

    This solar wind dominates the space environment within our solar system and travels well past Pluto, creating a huge bubble known as the heliosphere. Closer to home, the solar wind also interacts with Earth’s magnetic field, sometimes initiating changes in near-Earth space that can disrupt our space technology or cause auroras. So scientists needed to come up with a way to look at something that’s invisible—and that’s where Comet Encke came in.

    2
    Comet Encke’s ion tail can be seen stretching away from the sun towards the top of the image, captured by NASA’s MESSENGER spacecraft on Nov. 17, 2013, when the comet was about 33 million miles from the sun. The tail is created when the solar wind sweeps over the comet, capturing vaporized material and causing it to trail out behind the comet. The tail follows the lines of the magnetic field ingrained in the solar wind and reveals its motion. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/Southwest Research Institute

    All comets, if they get close enough to the sun, will form what’s called an ion tail. One of the most recognizable features of these hunks of ice and rock, the ion tail is created when the solar wind—made of hot, charged gas, called plasma—sweeps over the comet, capturing the material that has been vaporized into plasma by sunlight, causing it to trail out behind the comet. This tail follows the lines of the magnetic field embedded in the solar wind and reveals its motion.

    Comet Encke has some unusual characteristics that scientists were able to leverage to study the solar wind. Unlike most comets, Comet Encke has what is called a compact tail. Rather than feathering out loosely, creating a wide spray of ions, Comet Encke’s ion tail streams out in a tight, bright ribbon of glowing gas with compact features.

    3
    This video, captured by NASA’s STEREO mission, shows the motion of Comet Encke and its tail as it approached the sun in April 2007. Scientists studied the movements of hundreds of dense chunks of glowing ionized gas within the comet’s tail, finding evidence of turbulence that may explain both the solar wind’s variability and its unexpectedly high temperatures.
    Credits: NASA/STEREO

    “In situ measurements are limited because they don’t follow the turbulence along its path,” said William Matthaeus, a professor of physics and astronomy at the University of Delaware and co-author on the study. “Now, for the first time, we observed the turbulent motions along their complex paths and quantified the mixing. We actually see the turbulence.”

    Using the images from STEREO-A, scientists tracked 230 different features as they weaved through Comet Encke’s tail over the course of about 9.3 million miles of its journey around the sun. They then compared these motions to how they would expect solid objects to orbit around the sun, finding evidence that these gas clumps were being picked up by drag against the solar wind. They found that, though the gas clumps moved more or less randomly on smaller scales, they exhibited clear patterns on the scale of about 300,000 miles, indicating large-scale swirling eddies are mixing the solar wind—and possibly heating it as well.

    “Turbulent motion cascades down into motion on smaller and smaller scales until it hits the level of the fundamental gyrations of the particles about the magnetic field, where it becomes heat,” said Aaron Roberts, a heliophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This study estimates that there is enough energy contained in these swirling eddies to explain the extra heat several times over.”

    These observations of the solar wind provide a preview of what NASA plans to observe more directly with the Solar Probe Plus or SPP, mission in 2018.

    NASA SPP Solar Probe Plus

    SPP will travel to within nine solar radii of the sun, which is nine times the radius of the Sun, or about 3.9 million miles. Since it’s possible to remotely observe comets closer to the sun than any spacecraft can travel, studying them does provide unique information about the solar wind and our sun’s atmosphere.

    STEREO is the third mission in the NASA Heliophysics Division’s Solar Terrestrial Probes program, which is managed by NASA Goddard for NASA’s Science Mission Directorate, in Washington.

    Related:

    NASA’s STEREO project

    See the full article here .

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    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard Campus
    NASA/Goddard Campus
    NASA

     
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