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  • richardmitnick 8:41 am on May 22, 2019 Permalink | Reply
    Tags: Earth has its own magnetic field., , Lancaster University, , , Northern Lights, Reports that the magnetic north pole has started moving swiftly at 50km (31 miles) per year   

    From Lancaster University via EarthSky: “Magnetic north is shifting fast. What’ll happen to the northern lights?” 

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    From Lancaster University

    via

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    EarthSky

    May 22, 2019
    Nathan Case,
    Lancaster University

    As magnetic north shifts increasingly away from the geologic north pole – towards Siberia – studies suggest the northern lights could move with it.

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    Northern lights over Lake Lappajärvi in Finland. Image via Santeri Viinamäki.

    Like most planets in our solar system, the Earth has its own magnetic field. Thanks to its largely molten iron core, our planet is in fact a bit like a bar magnet.

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    It has a north and south magnetic pole, separate from the geographic poles, with a field connecting the two. This field protects our planet from radiation and is responsible for creating the northern and southern lights – spectacular events that are only visible near the magnetic poles.

    However, with reports that the magnetic north pole has started moving swiftly at 50km (31 miles) per year – and may soon be over Siberia – it has long been unclear whether the northern lights will move too. Now a new study, published in Geophysical Research Letters, has come up with an answer.

    Our planetary magnetic field has many advantages. For over 2,000 years, travellers have been able to use it to navigate across the globe. Some animals even seem to be able to find their way thanks to the magnetic field. But, more importantly than that, our geomagnetic field helps protect all life on Earth.

    Earth’s magnetic field extends hundreds of thousands of kilometers out from the center of our planet – stretching right out into interplanetary space, forming what scientists call a “magnetosphere”.

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

    This magnetosphere helps to deflect solar radiation and cosmic rays, preventing the destruction of our atmosphere. This protective magnetic bubble isn’t perfect though, and some solar matter and energy can transfer into our magnetosphere. As it is then funneled into the poles by the field, it results in the spectacular displays of the northern lights.

    A wandering pole

    Since Earth’s magnetic field is created by its moving, molten iron core, its poles aren’t stationary and they wander independently of one another. In fact, since its first formal discovery in 1831, the north magnetic pole has travelled over 1,240 miles (2,000 km) from the Boothia Peninsula in the far north of Canada to high in the Arctic Sea. This wandering has generally been quite slow, around 9km (6 mi) a year, allowing scientists to easily keep track of its position. But since the turn of the century, this speed has increased to 30 miles (50 km) a year. The south magnetic pole is also moving, though at a much slower rate (6-9 miles, or 10-15 km a year).

    This rapid wandering of the north magnetic pole has caused some problems for scientists and navigators alike. Computer models of where the north magnetic pole might be in the future have become seriously outdated, making accurate compass-based navigation difficult. Although GPS does work, it can sometimes be unreliable in the polar regions. In fact, the pole is moving so quickly that scientists responsible for mapping the Earth’s magnetic field were recently forced to update their model much earlier than expected.

    Will the aurora move?

    The aurora generally form in an oval about the magnetic poles, and so if those poles move, it stands to reason that the aurora might too. With predictions suggesting that the north pole will soon be approaching northern Siberia, what effect might that have on the aurora?

    The northern lights are currently mostly visible from northern Europe, Canada and the northern U.S. If, however, they shifted north, across the geographic pole, following the north magnetic pole, then that could well change. Instead, the northern lights would become more visible from Siberia and northern Russia and less visible from the much more densely populated U.S./Canadian border.

    Fortunately, for those aurora hunters in the northern hemisphere, it seems as though this might not actually be the case. A recent study made a computer model of the aurora and the Earth’s magnetic poles based on data dating back to 1965. It showed that rather than following the magnetic poles, the aurora follows the “geomagnetic poles” instead. There’s only a small difference between these two types of poles – but it’s an important one.

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    Magnetic versus geomagnetic poles. Image via Wikipedia.

    The magnetic poles are the points on the Earth’s surface where a compass needle points downwards or upwards, vertically. They aren’t necessarily connected and drawing a line between these points, through the Earth, would not necessarily cross its center. Therefore, to make better models over time, scientists assume that the Earth is like a bar magnet at its center, creating poles that are exactly opposite each other – “antipodal”. This means that if we drew a line between these points, the line would cross directly through the Earth’s center. At the points where that line crosses the Earth’s surface, we have the geomagnetic poles.

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    Positions of the north magnetic pole (red) and the geomagnetic pole (blue) between 1900 and 2020. Image via British Geological Survey.

    The geomagnetic poles are a kind of reliable, averaged out version of the magnetic poles, which move erratically all the time. Because of that, it turns out they aren’t moving anywhere near as fast as the magnetic north pole is. And since the aurora seems to follow the more averaged version of the magnetic field, it means that the northern lights aren’t moving that fast either. It seems as though the aurora are staying where they are – at least for now.

    We already know that the magnetic pole moves. Both poles have wandered ever since the Earth existed. In fact, the poles even flip over, with north becoming south and south becoming north. These magnetic reversals have occurred throughout history, every 450,000 years or so on average. The last reversal occurred 780,000 years ago meaning we could be due for a reversal soon.

    So rest assured that a wandering pole, even a fast one, shouldn’t cause too many problems – except for those scientists whose job it is to model it.

    Bottom line: Studies suggest that the northern lights could move as the Earth’s magnetic north pole heads towards Siberia.

    See the full article here .

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    Lancaster University (legally the University of Lancaster) is a collegiate public research university in Lancaster, Lancashire, England. The university was established by Royal Charter in 1964, one of several new universities created in the 1960s.

    The university was initially based in St Leonard’s Gate in the city centre, before moving in 1968 to a purpose-built 300 acres (120 ha) campus at Bailrigg, 4 km (2.5 mi) to the south. The campus buildings are arranged around a central walkway known as the Spine, which is connected to a central plaza, named Alexandra Square in honour of its first chancellor, Princess Alexandra.

    Lancaster is one of only six collegiate universities in the UK; the colleges are weakly autonomous. The eight undergraduate colleges are named after places in the historic county of Lancashire, and each have their own campus residence blocks, common rooms, administration staff and bar.

    Lancaster is ranked in the top ten in all three national league tables, and received a Gold rating in the Government’s inaugural (2017) Teaching Excellence Framework. In 2018 it was awarded University of the Year by The Times and Sunday Times Good University Guide, and achieved its highest ever national ranking of 6th place within the guide’s national table. The annual income of the institution for 2016–17 was £267.0 million of which £37.7 million was from research grants and contracts, with an expenditure of £268.7 million.

     
  • richardmitnick 7:48 am on February 19, 2018 Permalink | Reply
    Tags: , , , , , , Northern Lights   

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

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    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.

     
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