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  • richardmitnick 8:23 am on May 10, 2018 Permalink | Reply
    Tags: , , , , Earth's magnetosphere, , , NASA Spacecraft Discovers New Magnetic Process in Turbulent Space   

    From NASA Goddard Space Flight Center: “NASA Spacecraft Discovers New Magnetic Process in Turbulent Space” 

    NASA Goddard Banner
    From NASA Goddard Space Flight Center

    May 9, 2018

    Mara Johnson-Groh
    mara.johnson-groh@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    1
    In a turbulent magnetic environment, magnetic field lines become scrambled. As the field lines cross, intense electric currents (shown here as bright regions) form and eventually trigger magnetic reconnection (indicated by a flash), which is an explosive event that releases magnetic energy accumulated in the current layers and ejects high-speed bi-directional jets of electrons. Credit: NASA Goddard’s Conceptual Image Lab/Lisa Poje; Simulations by: University of Chicago/Colby Haggerty; University of Delaware/Tulasi Parashar

    Though close to home, the space immediately around Earth is full of hidden secrets and invisible processes. In a new discovery reported in the journal Nature, scientists working with NASA’s Magnetospheric Multiscale spacecraft — MMS — have uncovered a new type of magnetic event in our near-Earth environment by using an innovative technique to squeeze extra information out of the data.

    Magnetic reconnection is one of the most important processes in the space — filled with charged particles known as plasma — around Earth. This fundamental process dissipates magnetic energy and propels charged particles, both of which contribute to a dynamic space weather system that scientists want to better understand, and even someday predict, as we do terrestrial weather. Reconnection occurs when crossed magnetic field lines snap, explosively flinging away nearby particles at high speeds. The new discovery found reconnection where it has never been seen before — in turbulent plasma.


    In a new discovery reported in the journal Nature, scientists working with NASA’s Magnetospheric Multiscale spacecraft — MMS — uncovered a new type of magnetic event in our near-Earth environment. Credits: NASA’s Goddard Space Flight Center/Joy Ng

    NASA MMS prior to launch Credit: NASA/ Ben Smegelsky

    NASA MMS satellites in space. Credit: NASA

    “In the plasma universe, there are two important phenomena: magnetic reconnection and turbulence,” said Tai Phan, a senior fellow at the University of California, Berkeley, and lead author on the paper. “This discovery bridges these two processes.”

    Magnetic reconnection has been observed innumerable times in the magnetosphere — the magnetic environment around Earth — but usually under calm conditions. The new event occurred in a region called the magnetosheath, just outside the outer boundary of the magnetosphere, where the solar wind is extremely turbulent. Previously, scientists didn’t know if reconnection even could occur there, as the plasma is highly chaotic in that region. MMS found it does, but on scales much smaller than previous spacecraft could probe.


    In a turbulent magnetic environment, magnetic field lines become scrambled. As the field lines cross, intense electric currents (shown here as bright regions) form and eventually trigger magnetic reconnection (indicated by a flash), which is an explosive event that releases magnetic energy accumulated in the current layers and ejects high-speed bi-directional jets of electrons. NASA’s Magnetospheric Multiscale mission witnessed this process in action as it flew through the electron jets the turbulent boundary just at the edge of Earth’s magnetic environment. Credits: NASA’s Goddard Space Flight Center’s Conceptual Image Lab/Lisa Poje; Simulations by: Colby Haggerty (University of Chicago), Tulasi Parashar (University of Delaware)

    MMS uses four identical spacecraft flying in a pyramid formation to study magnetic reconnection around Earth in three dimensions. Because the spacecraft fly incredibly close together — at an average separation of just four-and-a-half miles, they hold the record for closest separation of any multi-spacecraft formation — they are able to observe phenomena no one has seen before. Furthermore, MMS’s instruments are designed to capture data at speeds a hundred times faster than previous missions.

    Even though the instruments aboard MMS are incredibly fast, they are still too slow to capture turbulent reconnection in action, which requires observing narrow layers of fast moving particles hurled by the recoiling field lines. Compared to standard reconnection, in which broad jets of ions stream out from the site of reconnection, turbulent reconnection ejects narrow jets of electrons only a couple miles wide.

    “The smoking gun evidence is to measure oppositely directed electron jets at the same time, and the four MMS spacecraft were lucky to corner the reconnection site and detect both jets”, said Jonathan Eastwood, a lecturer at Imperial College, London, and a co-author of the paper.

    Crucially, MMS scientists were able to leverage the design of one instrument, the Fast Plasma Investigation, to create a technique to interpolate the data — essentially allowing them to read between the lines and gather extra data points — in order to resolve the jets.

    “The key event of the paper happens in only 45 milliseconds. This would be one data point with the basic data,” said Amy Rager, a graduate student at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the scientist who developed the technique. “But instead we can get six to seven data points in that region with this method, allowing us to understand what is happening.”


    Earth is surrounded by a protective magnetic environment — the magnetosphere — shown here in blue, which deflects a supersonic stream of charged particles from the Sun, known as the solar wind. As the particles flow around Earth’s magnetosphere, it forms a highly turbulent boundary layer called the magnetosheath, shown in yellow. Scientists, like those involved with NASA’s Magnetospheric Multiscale mission, are studying this turbulent region to help us learn more about our dynamic space environment.
    Credits: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith; NASA Goddard’s Conceptual Image Lab/Josh Masters

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

    As the particles flow around Earth’s magnetosphere, it forms a highly turbulent boundary layer called the magnetosheath, shown in yellow [in video]. Scientists, like those involved with NASA’s Magnetospheric Multiscale mission, are studying this turbulent region to help us learn more about our dynamic space environment.
    Credits: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith; NASA Goddard’s Conceptual Image Lab/Josh Masters

    With the new method, the MMS scientists are hopeful they can comb back through existing datasets to find more of these events, and potentially other unexpected discoveries as well.

    Magnetic reconnection occurs throughout the universe, so that when we learn about it around our planet — where it’s easiest for Earthlings to examine it — we can apply that information to other processes farther away. The finding of reconnection in turbulence has implications, for example, for studies on the Sun. It may help scientists understand the role magnetic reconnection plays in heating the inexplicably hot solar corona — the Sun’s outer atmosphere — and accelerating the supersonic solar wind. NASA’s upcoming Parker Solar Probe mission launches directly to the Sun in the summer of 2018 to investigate exactly those questions — and that research is all the better armed the more we understand about magnetic reconnection near home.

    Related Links

    Learn more about the Magnetospheric Multiscale Mission
    Learn more about NASA’s research on the Sun-Earth environment

    See the full article here.

    See also here.

    See also 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

     
  • richardmitnick 7:48 am on February 19, 2018 Permalink | Reply
    Tags: , , , , Earth's magnetosphere, ,   

    From Many Worlds: “The Northern Lights, the Magnetic Field and Life” 

    NASA NExSS bloc

    NASA NExSS

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    Many Worlds

    2018-02-19
    Marc Kaufman

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    Northern Lights over a frozen lake in Northern Norway, inside the Arctic Circle near Alta. The displays can go on for hours, or can disappear for days or weeks. It all depends on solar flares. (Ongajok.no)

    May I please invite you to join me in the presence of one of the great natural phenomena and spectacles of our world.

    Not only is it enthralling to witness and scientifically crucial, but it’s quite emotionally moving as well.

    Why? Because what’s before me is a physical manifestation of one of the primary, but generally invisible, features of Earth that make life possible. It’s mostly seen in the far northern and far southern climes, but the force is everywhere and it protects our atmosphere and us from the parched fate of a planet like Mars.

    I’m speaking, of course, of the northern lights, the Aurora Borealis, and the planet’s magnetic fields that help turn on the lights.

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

    My vantage point is the far northern tip of Norway, inside the Arctic Circle. It’s stingingly cold in the silent woods, frozen still for the long, dark winter, and it’s always an unpredictable gift when the lights show up.

    But they‘re out tonight, dancing in bright green and sometimes gold-tinged arches and spotlights and twirling pinwheels across the northerly sky. Sometimes the horizon glows green, sometimes the whole sky fills with vivid green streaks.

    It can all seem quite other-worldly. But the lights, of course, are entirely the result of natural forces.

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    Northern Lights over north western Norway. Most of the lights are green from collisions with oxygen, but some are purple from nitrogen. © Copyright George Karbus Photography.

    It has been known for some time that the lights are caused by reactions between the high-energy particles of solar flares colliding in the upper regions of our atmosphere and then descending along the lines of the planet’s magnetic fields. Green lights tell of oxygen being struck at a certain altitude, red or blue of nitrogen.

    But the patterns — sometimes broad, sometimes spectral, sometimes curled and sometimes columnar — are the result of the magnetic field that surrounds the planet. The energy travels along the many lines of that field, and lights them up to make our magnetic blanket visible.

    Such a protective magnetic field is viewed as essential for life on a planet, be it in our solar system or beyond.

    But a magnetic field does not a habitable planet make. Mercury has a strong magnetic field and is certainly not habitable. Mars also once had a weak magnetic field and stir has some remnants on its surface. But it fell apart early in the planet’s life, and that may well have put a halt to the emergence or evolution of living things on the otherwise habitable planet.

    I will return to some of the features of the northern lights and the magnetism is makes visible, but this is also an opportunity to explore the role of magnetism in biology itself.

    This was a quasi-science for some time, but more recently it has been established that migrating birds and fish use magnetic sensors (in their beaks or noses, perhaps) to navigate northerly and southward paths.

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    Graphic from Science Magazine.

    But did you know that bacteria, insects and mammals of all sorts appear to have magnetic compasses as well? They can read the magnetism in the air, or can read it in the rocks (as in the case of some sea turtles.) A promising line of study, pioneered by scientists including geobiologist Joseph Kirschvink of the California Institute of Technology (Caltech) and the Earth-Life Science Institute (ELSI) in Tokyo, is even studying potentially remnant magnetic senses in humans.

    “There no doubt now that magnetic receptors are present in many, many species, and those that don’t have it probably lost it because it wasn’t useful to them,” he told me. “But there’s good reason to say that the magnetic sense was most likely one of the earliest on Earth.”

    But how does it work for animals? How do they receive the magnetic signals? This is a question of substantial study and debate.

    One theory states that creatures use the iron mineral magnetite — that they can produce and consume – to pick up the magnetic signals. These miniature compass needles sit within receptor cells, either near a creature’s nose or in the inner ear.

    Another posits that magnetic fields trigger quantum chemical reactions in proteins called cryptochromes, which have been found in the retina. But no one has determined how they might send signals and information to the brain.

    Kirschvink was part of a team that Earth’s magnetic field dates back to the Archean era, 3 to 3.5 billion years ago. “My guess is that magnetism has been a major influence in the biosphere since then, the biological ability to make magnetic materials.”

    He said that when the sun is particularly angry and active, the geomagnetic storms that occur around the planet seem to interfere with these magnetic responses and that animals don’t navigate as well.

    Kirschvink sees magnetism as a possibly important force in the origin of life. Magnetite that is lined up like beads on a chain has been detected in bacteria, and he says it may have provided an evolutionary pathway for structure that allowed for the rise of eukaryotes — organisms with complex cells, or a single cell with a complex structures.

    Kirschvink and his team are in the midst of a significant study of the effects of geomagnetism on humans, and the pathways through which that magnetism might be used.

    That’s rather a long way from some of the early biomagnetism discoveries, which involved the gumboot chiton. A mollusk relative of the snail and the limpet, the gumboot chiton holds on to rocks in the shallow water and uses its magnetite-covered teeth to scrape algae from rocks. The teeth are on a tongue-like feature called the radula and those teeth are capped with so much magnetite that a magnet can pick up the foot-long gumboot chiton.

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    The underside of a gumboot chiton, with its teeth covered with magnetite, can be lifted up with a magnet. No image credit.

    Back at most northern and southerly regions of the planet, where the magnetic field lines are most concentrated, the lights put on their displays for ever larger audiences of people who want to experience their presence.

    We had part of one night of almost full sky action, with long arches, curves large and small, waves, spotlights , shimmers and curtains. It had the feel of a spectacular fireworks display, but magnified in its glory and power and, of course, entirely natural. (I hope to post images taken by others that night which, alas, were not captured by my camera because the battery froze in the 10 degree cold.)

    Our grand night was one of the special ones when the colors (almost all greens, but some reds too) were so bright that their shapes and movements were easy to see with the naked eye.

    Good cameras (especially those with batteries that don’t freeze) see and capture a much broader range of the northern light presence. The horizon, for instance, can appear just slightly green to the naked eye, but will look quite brightly green in an image.

    Thanks to the National Oceanic and Atmospheric Administration, the National Weather Service and NASA, forecasting when and where the lights are likely to be be active in the northern and southern (the Aurora Australis) polar regions.

    This forecasting of space weather revolves around the the eruption of solar flares. The high-energy particles they send out collide with electrons in our upper atmosphere accelerate and follow the Earth’s magnetic fields down to the polar regions.

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    Models based on measuring solar flares, or coronal mass ejections, coming from sunspots that rotate and face Earth every 27 or 28 days. Summer months in the northern hemisphere often make the sky too light for the lights to be seen, so the long winter nights are generally the best time to see them. But they do appear in summer, too. (NOAA).

    In these collisions, the energy of the electrons is transferred to the oxygen and nitrogen and other elements in the atmosphere, in the process exciting the atoms and molecules to higher energy states. When they relax back down to lower energy states, they release their energy in the form of light. This is similar to how a neon light works.

    The aurora typically forms 60 to 400 miles above Earth’s surface.

    All this is possible because of our magnetic field, which scientists theorize was created and is sustained by interactions between super-hot liquid iron in the outer core of the Earth’s center and the rotation of the planet. The flowing or convection of liquid metal generates electric currents and the rotation of Earth causes these electric currents to form a magnetic field which extends around the planet.

    If the magnetic field wasn’t present those highly charged particles coming from the sun, the ones that set into motion the processes that produce the Northern and Southern Lights, would instead gradually strip the atmosphere of the molecules needed for life.

    This intimate relationship between the magnetic field and life led to me ask Kirschvink, who has been studying that connection for decades, if he had seen the northern or southern lights.

    No, he said, he’d never had the chance. But if ever in the presence of the lights, he said he know exactly what he would do: take out his equipment and start taking measurements and pushing his science forward.

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    Northern Lights in northern Norway, near Alta. Sometimes they dance for minutes, sometimes for hours, but often they never come at all. It all depends on the rotation of the sun; if and when it may be shooting out high-energy solar flares. (Wiki Commons)

    See the full article here .

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 9:17 am on February 16, 2018 Permalink | Reply
    Tags: , Earth's magnetosphere, , ,   

    From ESA: “Swarm details energetic coupling” 

    ESA Space For Europe Banner

    European Space Agency

    15 February 2018

    ESA/Swarm

    The Sun bathes our planet in the light and heat it needs to sustain life, but it also bombards us with dangerous charged particles in solar wind. Our magnetic field largely shields from this onslaught, but like many a relationship, it’s somewhat complicated. Thanks to ESA’s Swarm mission the nature of this Earth–Sun coupling has been revealed in more detail than ever before.

    Earth’s magnetic field is like a huge bubble, protecting us from cosmic radiation and charged particles carried by powerful winds that escape the Sun’s gravitational pull and sweep across the Solar System.

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

    The trio of Swarm satellites were launched in 2013 to improve our understanding of how the field is generated and how it protects us from this barrage of charged particles.

    Since our magnetic field is generated mainly by an ocean of liquid iron that makes up the planet’s outer core, it resembles a bar magnet with field lines emerging from near the poles.

    The field is highly conductive and carries charged particles that flow along these field lines, giving rise to field-aligned currents.

    Carrying up to 1 TW of electrical power – about six times the amount of energy produced every year by wind turbines in Europe – these currents are the dominant form of energy transfer between the magnetosphere and ionosphere.

    The shimmering green and purple light displays of the auroras in the skies above the polar regions are a visible manifestation of energy and particles travelling along magnetic field lines.

    3
    Aurora borealis
    Released 21/04/2017
    Copyright Sherwin Calaluan
    The aurora borealis is a visible display of electrically charged atomic particles from the Sun interacting with Earth’s magnetic field.

    The theory about the exchange and momentum between solar wind and our magnetic field actually goes back more than 100 years, and more recently the Active Magnetosphere and Planetary Electrodynamics Response Experiment satellite network has allowed scientists to study large-scale field-aligned currents.

    However, the Swarm mission is leading to exciting new wave of discoveries. A new paper [Journal of Geophysical Research] explores the dynamics of this energetic coupling across different spatial scales – and finds that it’s all in the detail.

    Ryan McGranaghan from NASA’s Jet Propulsion Laboratory said, “We have a good understanding of how these currents exchange energy between the ionosphere and the magnetosphere at large scales so we assumed that smaller-scale currents behaved in the same way, but carried proportionally less energy.”

    “Swarm has allowed us to effectively zoom in on these smaller currents and we see that, under certain conditions, this is not the case.

    ______________________________________________________________________________________________
    4
    Solar corona viewed by Proba-2
    Released 16/03/2015
    Copyright ESA/ROB
    This snapshot of our constantly changing Sun catches looping filaments and energetic eruptions on their outward journey from our star’s turbulent surface.

    The disc of our star is a rippling mass of bright, hot active areas, interspersed with dark, cool snaking filaments that wrap around the star. Surrounding the tumultuous solar surface is the chaotic corona, a rarified atmosphere of super-heated plasma that blankets the Sun and extends out into space for millions of kilometres.

    This coronal plasma reaches temperatures of several million degrees in some regions – significantly hotter than the surface of the Sun, which reaches comparatively paltry temperatures of around 6000ºC – and glows in ultraviolet and extreme-ultraviolet light owing to its extremely high temperature. By picking one particular wavelength, ESA’s Proba-2 SWAP (Sun Watcher with APS detector and Image Processing) camera is able to single out structures with temperatures of around a million degrees.

    ESA Proba 2

    As seen in the above image, taken on 25 July 2014, the hot plasma forms large loops and fan-shaped structures, both of which are kept in check by the Sun’s intense magnetic field. While some of these loops stay close to the surface of the Sun, some can stretch far out into space, eventually being swept up into the solar wind – an outpouring of energetic particles that constantly streams out into the Solar System and flows past the planets, including Earth.

    Even loops that initially appear to be quite docile can become tightly wrapped and tangled over time, storing energy until they eventually snap and throw off intense flares and eruptions known as coronal mass ejections. These eruptions, made up of massive amounts of gas embedded in magnetic field lines, can be dangerous to satellites, interfere with communication equipment and damage vital infrastructure on Earth.

    Despite the Sun being the most important star in our sky, much is still unknown about its behaviour. Studying its corona in detail could help us to understand the internal workings of the Sun, the erratic motions of its outer layers, and the highly energetic bursts of material that it throws off into space.

    Two new ESA missions will soon contribute to this field of study: Solar Orbiter is designed to study the solar wind and region of space dominated by the Sun and also to closely observe the star’s polar regions, and the Proba-3 mission will study the Sun’s faint corona closer to the solar rim than has ever before been achieved.

    NASA/ESA Solar Orbiter

    ESA Proba 3

    ______________________________________________________________________________________________

    “Our findings show that these smaller currents carry significant energy and that their relationship with the larger currents is very complex. Moreover, large and small currents affect the magnetosphere–ionosphere differently.”

    Colin Forsyth from University College London noted, “Since electric currents around Earth can interfere with navigation and telecommunication systems, this is an important discovery.

    “It also gives us a greater understanding of how the Sun and Earth are linked and how this coupling can ultimately add energy to our atmosphere.

    “This new knowledge can be used to improve models so that we can better understand, and therefore, ultimately, prepare for the potential consequences of solar storms.”

    ESA’s Swarm mission manager, Rune Floberghagen, added, “Since the beginning of the mission we have carried out projects to address the energy exchange between the magnetosphere, ionosphere and the thermosphere.

    “But what we are witnessing now is nothing short of a complete overhaul of the understanding of how Earth responds to and interacts with output from the Sun.

    “In fact, this scientific investigation is becoming a fundamental pillar for the extended Swarm mission, precisely because it is breaking new ground and at the same time has strong societal relevance. We now wish to explore this potential of Swarm to the fullest.”

    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 2:40 pm on December 2, 2017 Permalink | Reply
    Tags: A Shifting Shield Provides Protection Against Cosmic Rays, , , , , , Earth's magnetosphere, Spacecraft outside of Earth’s atmosphere and magnetic field are at risk of damage from cosmic rays   

    From AAS NOVA: “A Shifting Shield Provides Protection Against Cosmic Rays” 

    AASNOVA

    AAS NOVA

    1 December 2017
    Susanna Kohler

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    Artist’s impression of the shower of particles caused when a cosmic ray, a charged particle often produced by a distant astrophysical source, hits Earth’s upper atmosphere. [J. Yang/NSF]

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

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    Spacecraft outside of Earth’s atmosphere and magnetic field are at risk of damage from cosmic rays. [ESA]

    The Sun plays an important role in protecting us from cosmic rays, energetic particles that pelt us from outside our solar system. But can we predict when and how it will provide the most protection, and use this to minimize the damage to both piloted and robotic space missions?

    The Challenge of Cosmic Rays

    Galactic cosmic rays are high-energy, charged particles that originate from astrophysical processes — like supernovae or even distant active galactic nuclei — outside of our solar system.

    One reason to care about the cosmic rays arriving near Earth is because these particles can provide a significant challenge for space missions traveling above Earth’s protective atmosphere and magnetic field. Since impacts from cosmic rays can damage human DNA, this risk poses a major barrier to plans for interplanetary travel by crewed spacecraft. And robotic missions aren’t safe either: cosmic rays can flip bits, wreaking havoc on spacecraft electronics as well.

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    The magnetic field carried by the solar wind provides a protective shield, deflecting galactic cosmic rays from our solar system. [Walt Feimer/NASA GSFC’s Conceptual Image Lab]

    Shielded by the Sun

    Conveniently, we do have some broader protection against galactic cosmic rays: a built-in shield provided by the Sun. The interplanetary magnetic field, which is embedded in the solar wind, deflects low-energy cosmic rays from us at the outer reaches of our solar system, decreasing the flux of these cosmic rays that reach us at Earth.

    This shield, however, isn’t stationary; instead, it moves and changes as the strength and direction of the solar wind moves and changes. This results in a much lower cosmic-ray flux at Earth when solar activity is high — i.e., at the peak of the 11-year solar cycle — than when solar activity is low. This visible change in local cosmic-ray flux with solar activity is known as “solar modulation” of the cosmic ray flux at Earth.

    In a new study, a team of scientists led by Nicola Tomassetti (University of Perugia, Italy) has modeled this solar modulation to better understand the process by which the Sun’s changing activity influences the cosmic ray flux that reaches us at Earth.

    Modeling a Lag

    Tomassetti and collaborators’ model uses two solar-activity observables as inputs: the number of sunspots and the tilt angle of the heliospheric current sheet. By modeling basic transport processes in the heliosphere, the authors then track the impact that the changing solar properties have on incoming galactic cosmic rays. In particular, the team explores the time lag between when solar activity changes and when we see the responding change in the cosmic-ray flux.

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    Cosmic-ray flux observations are best fit by the authors’ model when an 8-month lag is included (red bold line). A comparison model with no lag (black dashed line) is included. [Tomassetti et al. 2017]

    By comparing their model outputs to the large collection of time-dependent observations of cosmic-ray fluxes, Tomassetti and collaborators show that the best fit to data occurs with an ~8-month lag between changing solar activity and local cosmic-ray flux modulation.

    This is an important outcome for studying the processes that affect the cosmic-ray flux that reaches Earth. But there’s an additional intriguing consequence of this result: knowledge of the current solar activity could allow us to predict the modulation that will occur for cosmic rays near Earth an entire 8 months from now! If this model is correct, it brings us one step closer to being able to plan safer space missions for the future.

    Citation

    Nicola Tomassetti et al 2017 ApJL 849 L32. doi:10.3847/2041-8213/aa9373

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    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

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  • richardmitnick 1:12 pm on May 27, 2017 Permalink | Reply
    Tags: 1 millionº and breezy: Your solar forecast, , , Earth's magnetosphere, , ,   

    From Science Node: “1 millionº and breezy: Your solar forecast” 

    Science Node bloc
    Science Node

    24 May, 2017
    Alisa Alering

    Space is a big place, so modeling activities out there calls for supercomputers that match. PRACE provided scientists the resources to run the Vlasiator code and simulate the solar wind around the earth.

    1
    Courtesy Minna Palmroth; Finnish Meteorological Institute.

    Outer space is a tough place to be a lonely blue planet.

    With only a thin atmosphere standing between a punishing solar wind and the 1.5 million species living on its surface, any indication of the solar mood is appreciated.

    The sun emits a continuous flow of plasma traveling at speeds up to 900 km/s and temperatures as high as 1 millionº Celsius. The earth’s magnetosphere blocks this wind and allows it to flow harmlessly around the planet like water around a stone in the middle of a stream.

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

    But under the force of the solar bombardment, the earth’s magnetic field responds dramatically, changing size and shape. The highly dynamic conditions this creates in near-Earth space is known as space weather.

    Vlasiator, a new simulation developed by Minna Palmroth, professor in computational space physics at the University of Helsinki, models the entire magnetosphere. It helps scientists to better understand interesting and hard-to-predict phenomena that occur in near-Earth space weather.

    Unlike previous models that could only simulate a small segment of the magnetosphere, Vlasiator allows scientists to study causal relationships between plasma phenomena for the first time and to consider smaller scale phenomena in a larger context.

    “With Vlasiator, we are simulating near-Earth space with better accuracy than has even been possible before,” says Palmroth.

    Navigating near-Earth

    Over 1,000 satellites and other near-Earth spacecraft are currently in operation around the earth, including the International Space Station and the Hubble Telescope.

    Nearly all communications on Earth — including television and radio, telephone, internet, and military — rely on links to these spacecraft.

    Still other satellites support navigation and global positioning and meteorological observation.

    New spacecraft are launched every day, and the future promises even greater dependence on their signals. But we are launching these craft into a sea of plasma that we barely understand.

    “Consider a shipping company that would send its vessel into an ocean without knowing what the environment was,” says Palmroth. “That wouldn’t be very smart.”

    Space weather has an enormous impact on spacecraft, capable of deteriorating signals to the navigation map on your phone and disrupting aviation. Solar storms even have the potential to overwhelm transformers and black out the power grid.

    Through better comprehension and prediction of space weather, Vlasiator’s comprehensive model will help scientists protect vital communications and other satellite functions.

    Three-level parallelization

    The Vlasiator’s simulations are so detailed that it can model the most important physical phenomena in the near-Earth space at the ion-kinetic scale. This amounts to a volume of 1 million km3 — a massive computational challenge that has not previously been possible.

    After being awarded several highly competitive grants from the European Research Council, Palmroth secured computation time on HPC resources managed by the Partnership for Advanced Computing in Europe (PRACE).

    4
    Hazel Hen

    She began with the Hornet supercomputer and then its successor Hazel Hen, both at the High-Performance Computing Center Stuttgart. Most recently she has been using the Marconi supercomputer at CINECA in Italy.

    7
    Marconi supercomputer at CINECA in Italy

    Palmroth’s success is due to three-level parallelization of the simulation code. Her team uses domain decomposition to split the near-Earth space into grid cells within each area they wish to simulate.

    They use load-balancing to divide the simulations and then parallelize using OpenMP. Finally, they vectorize the code to parallelize through the supercomputer’s cores.

    Even so, simulation datasets range from 1 to 100 terabytes, depending on how often they save the simulations, and require anywhere between 500 – 100,000 cores, possibly beyond, on Hazel Hen.

    “We are continuously making algorithmic improvements in the code, making new optimizations, and utilizing the latest advances in HPC to improve the efficiency of the calculations all the time,” says Palmroth.

    Taking off into the future

    In addition to advancing our knowledge of space weather, Vlasiator also helps scientists to better understand plasma physics. Until now, most fundamental plasma physical phenomena have been discovered from space because it’s the best available laboratory.

    But the universe is comprised of 99.9 percent plasma, the fourth state of matter. In order to understand the universe, you need to understand plasma physics. For scientists undertaking any kind of matter research, Vlasiator’s capacity to simulate the near-Earth space is significant.

    “As a scientist, I’m curious about what happens in the world,” says Palmroth. “I can’t really draw a line beyond which I don’t want to know what happens.”

    Significantly, Vlasiator has recently helped to explain some features of ultra-low frequency waves in the earth’s foreshock that have perplexed scientists for decades.

    A collaboration with NASA in the US helped validate those results with the THEMIS spacecraft, a constellation of five identical probes designed to gather information about large-scale space physics.

    Exchanging information with her colleagues at NASA allows Palmroth to get input from THEMIS’s direct observation of space phenomena and to exchange modeling results with the observational community.

    “The work we are doing now is important for the next generation,” says Palmroth. “We’re learning all the time. If future generations build upon our advances, their understanding of the universe will be on much more certain ground.”

    See the full article here .

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    Science Node is an international weekly online publication that covers distributed computing and the research it enables.

    “We report on all aspects of distributed computing technology, such as grids and clouds. We also regularly feature articles on distributed computing-enabled research in a large variety of disciplines, including physics, biology, sociology, earth sciences, archaeology, medicine, disaster management, crime, and art. (Note that we do not cover stories that are purely about commercial technology.)

    In its current incarnation, Science Node is also an online destination where you can host a profile and blog, and find and disseminate announcements and information about events, deadlines, and jobs. In the near future it will also be a place where you can network with colleagues.

    You can read Science Node via our homepage, RSS, or email. For the complete iSGTW experience, sign up for an account or log in with OpenID and manage your email subscription from your account preferences. If you do not wish to access the website’s features, you can just subscribe to the weekly email.”

     
  • richardmitnick 9:48 am on October 31, 2016 Permalink | Reply
    Tags: , , , Earth's magnetosphere,   

    From Science: “Solar storms can weaken Earth’s magnetic field” 

    ScienceMag
    Science Magazine

    1
    A coronal mass ejection in 2015, seen here by NASA’s Solar Dynamics Observatory, ended up weakening Earth’s magnetic field.

    Oct. 31, 2016
    Katherine Kornei

    The sun’s warm glow can sometimes turn menacing. Solar storms can shoot plasma wrapped in bits of the sun’s magnetic field into space, sweeping past Earth and disabling satellites, causing widespread blackouts, and disrupting GPS-based navigation. Now, a new study suggests that one such “coronal mass ejection” in 2015 temporarily weakened Earth’s protective magnetic field, allowing solar plasma and radiation from the same storm to more easily reach the atmosphere, potentially posing a danger to astronauts. The study also suggests a potential way to predict such storms in the future.

    On 21 June 2015, a NASA spacecraft called the Solar and Heliospheric Observatory recorded a coronal mass ejection blasting off the sun at roughly 1300 kilometers per second.

    ESA/NASA SOHO
    “ESA/NASA SOHO

    When the burst reached Earth roughly 40 hours later, its magnetic field was oriented opposite to Earth’s own magnetic field, which caused the fields to be attracted to each other and to interact strongly. “It is like bringing two magnets close together,” says physicist Sunil Gupta of the Tata Institute of Fundamental Research in Mumbai, India, and lead author of the new study.

    The resulting interaction converted magnetic energy into kinetic energy and sent charged particles such as cosmic rays raining down on Earth’s magnetosphere, the region around Earth where its own magnetic field is stronger than other magnetic fields in space. The National Oceanic and Atmospheric Administration (NOAA) rated the geomagnetic storm 4 out of 5 on its scale of storm severity. Radio blackouts were reported, and the aurora borealis was spotted as far south as Texas.

    Gupta and his team collected data from a telescope in India that measures the number of charged particles called muons that are created as byproducts when cosmic rays hit Earth’s atmosphere. Looking at data from 22 June 2015, they found a statistically significant spike in the number of muons that day. This result was consistent with a weakening of Earth’s magnetic field that allowed cosmic rays to stream more freely through Earth’s magnetnosphere and into the atmosphere without being deflected.

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

    “The weakening of Earth’s magnetic field opens up floodgates for low-energy solar plasma to pour into the atmosphere,” says Gupta, whose team reports its findings this month in Physical Review Letters.

    Overall, the team showed that Earth’s magnetic field is susceptible to temporary damage, rendering our planet’s atmosphere the last line of defense against energetic particles from space. Without Earth’s magnetic field, astronauts above the atmosphere are exposed to particles that can rip through human bodies and damage DNA, potentially causing cancer.

    The new results also suggest a possible method to detect impending geomagnetic storms. A successful early warning system is key to reducing the economic impact of such storms, which has been estimated by the National Academy of Sciences to be several trillion dollars in the most severe cases. Even with only a few hours of advance warning, power grids could redistribute currents to reduce their vulnerability to currents traveling through Earth and airplanes flying polar routes could be rerouted to avoid losing radio contact with controllers, for example.

    Gupta and his colleagues propose using muons as early detectors of geomagnetic storms. The scientists begin by assuming that particles with lower energies take longer to travel through turbulent magnetic fields, much like a lazy moth takes longer to cross a windy valley than a quick bee. They accordingly reasoned that the highly energetic cosmic rays creating muons would reach Earth’s atmosphere ahead of the solar plasma and lower-energy cosmic rays that can be the brunt of a geomagnetic storm. “The muon burst could in principle serve as an early warning system before a storm,” Gupta says. “But a lot of research needs to be done to make it a practical proposition.”

    James Chen, a plasma physicist at the Naval Research Laboratory in Washington, D.C., says that predicting the future might not be so simple. “[The muon burst] is part of an ongoing storm so it may have little forecasting value,” he says.

    The results of Gupta and his team are timely: NOAA issued an alert last week warning of an impending “strong” geomagnetic storm. However, even when spotted by spacecraft, the predicted arrival times of storms are uncertain because they are based on simulations of how coronal mass ejections propagate through space. An Earth-based early alert system, based on particle data, might give less warning but be significantly more accurate.

    Earlier this month, U.S. President Barack Obama signed an executive order mandating that the U.S. government “mitigate the effects of geomagnetic disturbances on the electrical power grid” and “ensure the timely redistribution of space weather alerts.” Our technological society, for all of its advances, is still susceptible to the whims of our closest star.

    See the full article here .

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  • richardmitnick 3:08 pm on May 22, 2016 Permalink | Reply
    Tags: , Earth's magnetosphere, NASA BARRELL,   

    From Goddard: “NASA Mini-Balloon Mission Maps Migratory Magnetic Boundary” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    May 19, 2016
    Sarah Frazier
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    1
    A BARREL balloon launches over Halley Research Station during the Antarctic summer of 2013-2014. The BARREL mission was created to observe precipitating electrons from Earth’s radiation belts, supplementing observations by NASA’s Van Allen Probes. During a January 2014 solar storm, BARREL measured solar electrons in addition to radiation belt electrons, allowing the team to map how parts of Earth’s magnetic field shift and change during a solar storm. Credits: NASA/BARREL

    2
    Six BARREL balloons flew above Antarctica during a January 2014 solar storm. The different-colored tracks trace out the paths of the balloons. Together, the measurements from these balloons showed how Earth’s magnetic field shifts during a solar storm. The BARREL balloons were launched from Antarctic research stations SANAE IV and Halley VI. Credits: NASA/Halford, et al.

    3
    Near Earth’s magnetic poles, some of Earth’s magnetic field – shown as red in this diagram – loops out into space and connects back to Earth. But some of Earth’s polar magnetic field connects directly to the sun’s magnetic field, shown here in white. Balloons from NASA’s BARREL mission mapped the boundary between these two types of magnetic connection as it shifted and changed during an event called a solar storm. Credits: NASA

    During the Antarctic summer of 2013-2014, a team of researchers released a series of translucent scientific balloons, one by one. The miniature membranous balloons – part of the Balloon Array for Radiation-belt Relativistic Electron Losses, or BARREL, campaign – floated above the icy terrain for several weeks each, diligently documenting the rain of electrons falling into the atmosphere from Earth’s magnetic field.

    Then in January 2014, BARREL’s observations saw something never seen before. During a fairly common space event called a solar storm – when a cloud of strongly magnetic solar material collides with Earth’s magnetic field – BARREL mapped for the first time how the storm caused Earth’s magnetic field to shift and move. The fields’ configuration shifted much faster than expected: on the order of minutes. These results were published* in the Journal of Geophysical Research on May 12, 2016. Understanding how our near-Earth space environment changes in response to solar storms helps us protect our technology in space.

    During this solar storm, three BARREL balloons were flying through parts of Earth’s magnetic field that directly connect a region of Antarctica to Earth’s north magnetic pole – these parts of the magnetic field are called closed field lines, because both ends are rooted on Earth. One BARREL balloon was on a field line with one end on Earth and one end connected to the sun’s magnetic field, an open field line. And two balloons switched back and forth between closed and open field lines throughout the solar storm, providing a map of how the boundary between open and closed field lines moved as a result of the storm.

    “It’s very difficult to model that open-closed boundary,” said Alexa Halford, a space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This will help with our simulations of how magnetic fields change around Earth, because we’re able to state exactly where we saw this boundary.”

    We live in the extended atmosphere of a magnetically active star – which, in part, means that we’re constantly in the path of the sun’s outflow of charged particles, called the solar wind.

    Most of the solar wind particles are fairly slow, but even the fastest particles – accelerated to high speeds by explosions on the sun or pushed along by clouds of solar material – are deflected away from Earth’s surface by our planet’s magnetic field. Most of Earth’s magnetic field has a foot point in a region near Antarctica, called the south magnetic pole. Much of this magnetic field loops up out into space, but then connects back to Earth at the north magnetic pole, near the Arctic Circle. This looped part of the magnetic field – the closed magnetic field – creates a barrier against charged particles, repelling them from reaching Earth.

    But a smaller portion of Earth’s magnetic field is open, connecting to the sun’s magnetic field, instead of curving back toward Earth. It’s this open magnetic field that gives charged particles from the sun a path into Earth’s atmosphere. Once particles are stuck to an open field line, they can rocket down into the upper atmosphere to collide with neutral atoms, creating a type of aurora.

    The boundary between these open and closed regions of Earth’s magnetic field is anything but constant. Due to various causes – such as incoming clouds of solar material – the closed magnetic field lines can realign into open field lines and vice versa, changing the location of the boundary between open and closed magnetic field lines.

    Scientists have known that the open-closed boundary moves, but it’s hard to pinpoint exactly how, when, and how quickly it changes – and that’s where BARREL comes in. The six BARREL balloons flying during the January 2014 solar storm were able to map these changes, and they found something surprising – the open-closed boundary moves relatively quickly, changing location within minutes.

    BARREL was designed to study how electrons from Earth’s radiation belts – vast swaths of particles trapped in Earth’s magnetic field hundreds of miles above the surface – can make their way down into the atmosphere. The BARREL campaign is primarily tasked with supplementing observations by NASA’s Van Allen Probes, which are dedicated to studying these radiation belts.

    NASA Van Allen Probes
    NASA Van Allen Probes

    However, solar energetic electrons happen to be in the same energy range as those radiation belt electrons, meaning that BARREL can see both.

    “The scientists used balloon observations of solar particles entering Earth’s magnetic field to locate the outer boundary of Earth’s magnetic field, many tens of thousands of miles away,” said David Sibeck, a space scientist at Goddard and mission scientist at NASA for the Van Allen Probes. “This isn’t what BARREL was intended for, but it’s a wonderful bonus science return.”

    The Antarctic is dotted with ground-based systems that, like BARREL, can measure the influx of radiation belt electrons. But because of their design, these detectors are overwhelmed by solar protons – which generally far outnumber solar electrons during solar particle events – meaning they’re unable to differentiate between the particles that come from the sun versus those that come from the radiation belts. On the other hand, BARREL is finely tuned to see electrons, meaning that the accompanying barrage of solar protons doesn’t drown out the electrons in BARREL’s detectors.

    “Protons create signatures in a very small energy range, while electron signatures show up in a wide range of energies,” said Halford. “But the electron energies are usually well below the proton energy, so we can tell them apart.”

    It is possible – but unlikely – that complex dynamics in the magnetosphere gave the appearance that the BARREL balloons were dancing along this open-closed boundary. If a very fast magnetic wave was sending radiation belt electrons down into the atmosphere in short, stuttering bursts, it could appear that the balloons were switching between open and closed magnetic field lines.

    However, the particle counts measured by the two balloons on the open-closed boundary matched up to those observed by the other BARREL balloons – hovering on closed or open field lines only – strengthening the case that BARREL’s balloons were actually crossing the boundary between solar and terrestrial magnetic field.

    Related Links

    NASA’s BARREL website
    Paper in the Journal of Geophysical Research

    *Science paper:
    BARREL observations of a solar energetic electron and solar energetic proton event

    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 9:52 am on May 10, 2016 Permalink | Reply
    Tags: , , Earth's magnetosphere, Earth’s magnetic heartbeat,   

    From ESA: “Earth’s magnetic heartbeat” 

    ESA Space For Europe Banner

    European Space Agency

    10 May 2016

    With more than two years of measurements by ESA’s Swarm satellite trio, changes in the strength of Earth’s magnetic field are being mapped in detail.

    ESA/Swarm

    Launched at the end of 2013, Swarm is measuring and untangling the different magnetic signals from Earth’s core, mantle, crust, oceans, ionosphere and magnetosphere – an undertaking that will take several years to complete.

    Although invisible, the magnetic field and electric currents in and around Earth generate complex forces that have immeasurable effects on our everyday lives.

    Magnetosphere of Earth
    Magnetosphere of Earth

    The field can be thought of as a huge bubble, protecting us from cosmic radiation and electrically charged atomic particles that bombard Earth in solar winds. However, it is in a permanent state of flux.

    Presented at this week’s Living Planet Symposium, new results from the constellation of Swarm satellites show where our protective field is weakening and strengthening, and importantly how fast these changes are taking place.

    The animation above shows the strength of Earth’s magnetic field and how it changed between 1999 and May 2016.

    Blue depicts where the field is weak and red shows regions where it is strong. As well as recent data from the Swarm constellation, information from the CHAMP and Ørsted satellites were also used to create the map.

    It shows clearly that the field has weakened by about 3.5% at high latitudes over North America, while it has strengthened about 2% over Asia. The region where the field is at its weakest – the South Atlantic Anomaly – has moved steadily westward and weakened further by about 2%.

    In addition, the magnetic north pole is wandering east, towards Asia.

    The second animation shows the rate of change in Earth’s magnetic field between 2000 and 2015. Regions where changes in the field slowed are shown in blue while red shows where changes speeded up.

    For example, changes in the field have slowed near South Africa, but have changed faster over Asia.

    The magnetic field is thought to be produced largely by an ocean of molten, swirling liquid iron that makes up our planet’s outer core, 3000 km under our feet. Acting like the spinning conductor in a bicycle dynamo, it generates electrical currents and thus the continuously changing electromagnetic field.

    It is thought that accelerations in field strength are related to changes in how this liquid iron flows and oscillates in the outer core.

    Chris Finlay, senior scientist at DTU Space in Denmark, said, “Swarm data are now enabling us to map detailed changes in Earth’s magnetic field, not just at Earth’s surface but also down at the edge of its source region in the core.

    “Unexpectedly, we are finding rapid localised field changes that seem to be a result of accelerations of liquid metal flowing within the core.”

    Rune Floberghagen, ESA’s Swarm mission manager, added, “Two and a half years after the mission was launched it is great to see that Swarm is mapping the magnetic field and its variations with phenomenal precision.

    “The quality of the data is truly excellent, and this paves the way for a profusion of scientific applications as the data continue to be exploited.”

    It is clear that ESA’s innovative Swarm mission is providing new insights into our changing magnetic field. Further results are expected to lead to new information on many natural processes, from those occurring deep inside the planet to weather in space caused by solar activity.

    In turn, this information will certainly yield a better understanding of why the magnetic field is weakening in some places, and globally.

    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 11:52 am on March 16, 2016 Permalink | Reply
    Tags: , , , Earth's magnetosphere, Kappa Ceti - A young star   

    From CfA: “Young Sun-like Star Shows a Magnetic Field Was Critical for Life on the Early Earth” 

    Harvard Smithsonian Center for Astrophysics


    Center For Astrophysics

    March 16, 2016
    Christine Pulliam
    Media Relations Manager
    Harvard-Smithsonian Center for Astrophysics
    617-495-7463
    cpulliam@cfa.harvard.edu

    Kappa Ceti young star Credit M. Weiss CfA
    Artist’s illustration, the young Sun-like star Kappa Ceti. Credit: M. Weiss/CfA

    Nearly four billion years ago, life arose on Earth. Life appeared because our planet had a rocky surface, liquid water, and a blanketing atmosphere. But life thrived thanks to another necessary ingredient: the presence of a protective magnetic field. A new study of the young, Sun-like star Kappa Ceti shows that a magnetic field plays a key role in making a planet conducive to life.

    “To be habitable, a planet needs warmth, water, and it needs to be sheltered from a young, violent Sun,” says lead author Jose-Dias Do Nascimento of the Harvard-Smithsonian Center for Astrophysics (CfA) and University of Rio G. do Norte (UFRN), Brazil.

    Kappa Ceti, located 30 light-years away in the constellation Cetus, the Whale, is remarkably similar to our Sun but younger. The team calculates an age of only 400-600 million years old, which agrees with the age estimated from its rotation period (a technique pioneered by CfA astronomer Soren Meibom). This age roughly corresponds to the time when life first appeared on Earth. As a result, studying Kappa Ceti can give us insights into the early history of our solar system.

    Like other stars its age, Kappa Ceti is very magnetically active. Its surface is blotched with many giant starspots, like sunspots but larger and more numerous. It also propels a steady stream of plasma, or ionized gases, out into space. The research team found that this stellar wind is 50 times stronger than our Sun’s solar wind.

    Such a fierce stellar wind would batter the atmosphere of any planet in the habitable zone, unless that planet was shielded by a magnetic field. At the extreme, a planet without a magnetic field could lose most of its atmosphere. In our solar system, the planet Mars suffered this fate and turned from a world warm enough for briny oceans to a cold, dry desert.

    The team modeled the strong stellar wind of Kappa Ceti and its effect on a young Earth. The early Earth’s magnetic field is expected to have been about as strong as it is today, or slightly weaker. Depending on the assumed strength, the researchers found that the resulting protected region, or magnetosphere, of Earth would be about one-third to one-half as large as it is today.

    “The early Earth didn’t have as much protection as it does now, but it had enough,” says Do Nascimento.

    Kappa Ceti also shows evidence of “superflares” — enormous eruptions that release 10 to 100 million times more energy than the largest flares ever observed on our Sun. Flares that energetic can strip a planet’s atmosphere. By studying Kappa Ceti, researchers hope to learn how frequently it produces superflares, and therefore how often our Sun might have erupted in its youth.

    This research has been accepted for publication in The Astrophysical Journal Letters and is available online. This set of Kappa Ceti observations were part of the Bernard Lyot Telescope‘s Bcool Large Program.

    Bernard Lyot telescope
    Bernard Lyot telescope interior
    Bernard Lyot Telescope. Observatoire Midi Pyrenees

    See the full article here .

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    The Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
  • richardmitnick 4:06 pm on February 10, 2016 Permalink | Reply
    Tags: , , , , Earth's magnetosphere, Owens Valley Long Wavelength Array, ,   

    From Caltech: “Chasing Extrasolar Space Weather” 

    Caltech Logo
    Caltech

    02/10/2016
    Lori Dajose

    Earth’s magnetic field acts like a giant shield, protecting the planet from bursts of harmful charged solar particles that could strip away the atmosphere.

    Magnetosphere of Earth
    Earth’s magnetosphere

    Gregg Hallinan, an assistant professor of astronomy, aims to detect this kind of space weather on other stars to determine whether planets around these stars are also protected by their own magnetic fields and how that impacts planetary habitability.

    On Wednesday, February 10, at 8 p.m. in Beckman Auditorium, Hallinan will discuss his group’s efforts to detect intense radio emissions from stars and their effects on any nearby planets. Admission is free.

    What do you do?
    I am an astronomer. My primary focus is the study of the magnetic fields of stars, planets, and brown dwarfs—which are kind of an intermediate object between a planet and a star.

    Brown dwarf
    Brown dwarf

    Stars and their planets have intertwined relationships. Our sun, for example, produces coronal mass ejections, or CMEs, which are bubbles of hot plasma explosively ejected from the sun out into the solar system.

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

    Radiation and particles from these solar events bombard the earth and interact with the atmosphere, dominating the local “space weather” in the environment of Earth. Happily, our planet’s magnetic field shields and redirects CMEs toward the polar regions. This causes auroras—the colorful light in the sky commonly known as the Northern or Southern Lights.

    Auroras from around the world
    Auroras from around the world

    Our new telescope, the Owens Valley Long Wavelength Array, images the entire sky instantaneously and allows us to monitor extrasolar space weather on thousands of nearby stellar systems.

    Caltech Owens Valley Long Wavelength Array
    Caltech Owens Valley Long Wavelength Array

    When a star produces a CME, it also emits a bright burst of radio waves with a specific signature. If a planet has a magnetic field and it is hit by one of these CMEs, it will also become brighter in radio waves. Those radio signatures are very specific and allow you to measure very precisely the strength of the planet’s magnetic field. I am interested in detecting radio waves from exoplanets—planets outside of our solar system—in order to learn more about what governs whether or not a planet has a magnetic field.

    Why is this important?

    The presence of a magnetic field on a planet can tell us a lot. Like on our own planet, magnetic fields are an important line of defense against the solar wind, particularly explosive CMEs, which can strip a planet of its atmosphere. Mars is a good example of this. Because it didn’t have a magnetic field shielding it from the sun’s solar wind, it was stripped of its atmosphere long ago. So, determining whether a planet has a magnetic field is important in order to determine which planets could possibly have atmospheres and thus could possibly host life.

    How did you get into this line of work?

    From a young age, I was obsessed with astronomy—it’s all I cared for. My parents got me a telescope when I was 7 or 8, and from then on, that was it.

    As a grad student, I was looking at magnetic fields of cool—meaning low-temperature—objects. When I was looking at brown dwarfs, I found that they behave like planets in that they also have auroras. I had the idea that auroras could be the avenue to examine the magnetic fields of other planets. So brown dwarfs were my gateway into exoplanets.

    See the full article here .

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    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.”
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