A crack in Earth's magnetic shield?

Discussion in 'General Science & Technology' started by paddoboy, Nov 11, 2016.

  1. paddoboy Valued Senior Member

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    GRAPES-3 indicates a crack in Earth's magnetic shield
    November 3, 2016

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    The GRAPES-3 muon telescope, the largest and most sensitive cosmic ray monitor recorded a burst of galactic cosmic rays that indicated a crack in the Earth's magnetic shield Credit: TIFR
    The GRAPES-3 muon telescope, the largest and most sensitive cosmic ray monitor recorded a burst of galactic cosmic rays that indicated a crack in the Earth's magnetic shield. The burst occurred when a giant cloud of plasma ejected from the solar corona struck Earth at a very high speed causing massive compression of the Earth's magnetosphere and triggering a severe geomagnetic storm.


    The GRAPES-3 muon telescope located at TIFR's Cosmic Ray Laboratory in Ooty recorded a burst of galactic cosmic rays of about 20 GeV, on 22 June 2015 lasting for two hours.

    The burst occurred when a giant cloud of plasma ejected from the solar corona, and moving with a speed of about 2.5 million kilometers per hour struck our planet, causing a severe compression of Earth's magnetosphere from 11 to 4 times the radius of Earth. It triggered a severe geomagnetic storm that generated aurora borealis, and radio signal blackouts in many high latitude countries.



    Read more at: http://phys.org/news/2016-11-grapes-earth-magnetic-shield.html#jCp
     
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  3. paddoboy Valued Senior Member

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    http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.171101

    Transient Weakening of Earth’s Magnetic Shield Probed by a Cosmic Ray Burst:

    ABSTRACT
    The GRAPES-3 tracking muon telescope in Ooty, India measures muon intensity at high cutoff rigidities (15–24 GV) along nine independent directions covering 2.3 sr. The arrival of a coronal mass ejection on 22 June 2015 18:40 UT had triggered a severe G4-class geomagnetic storm (storm). Starting 19:00 UT, the GRAPES-3 muon telescope recorded a 2 h high-energy (∼20GeV) burst of galactic cosmic rays (GCRs) that was strongly correlated with a 40 nT surge in the interplanetary magnetic field (IMF). Simulations have shown that a large (17×) compression of the IMF to 680 nT, followed by reconnection with the geomagnetic field (GMF) leading to lower cutoff rigidities could generate this burst. Here, 680 nT represents a short-term change in GMF around Earth, averaged over 7 times its volume. The GCRs, due to lowering of cutoff rigidities, were deflected from Earth’s day side by ∼210° in longitude, offering a natural explanation of its night-time detection by the GRAPES-3. The simultaneous occurrence of the burst in all nine directions suggests its origin close to Earth. It also indicates a transient weakening of Earth’s magnetic shield, and may hold clues for a better understanding of future superstorms that could cripple modern technological infrastructure on Earth, and endanger the lives of the astronauts in space.

     
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  5. danshawen Valued Senior Member

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    "Knowing" (Nicholas Cage, 2009) that a coronal mass ejection could wipe out all life on Earth in 24 hours if it occurs at a time when the Earth's magnetic poles are in the process of reversing is something few people consider even a fleeting possibility. Evidently, a somewhat smaller version of such an event has already happened recently.

    So, what could Trump do, other than cut or try and privatize funding to NASA, that is? If you have an idea, please tell us before it's too late, because he is unlikely to come up with a solution other than to deny it by himself or with the "help" of any associates he hasn't already fired. Too real to laugh at on reality TV.
     
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  7. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member

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    Serously, there have been a large number of field reversals over the ages. coronal mass ejections are not uncommon. the likelihood that they have occurred during previous reversals is quite large. the likelihood that they would "wipe out all life on earth" is therefore quite small.
     
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  8. danshawen Valued Senior Member

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    Knowledge conquers fear. Knowing that life is a game of chance only gets you a casino mogul for president. Chances are about as slim things will improve. You bet your life.
     
  9. Fraggle Rocker Staff Member

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    A "casino mogul" gets rich from the business. He doesn't go bankrupt!
     

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