NASA to Investigate Magnetic Explosions   
       
   March 10, 2015:  Magnetic reconnection could be the Universe's favorite way to   
   make things explode.   
       
   It operates anywhere magnetic fields pervade space--which is to say almost   
   everywhere. In the cores of galaxies, magnetic reconnection sparks explosions   
   visible billions of light-years away. On the sun, it causes solar flares as   
   powerful as a million atomic bombs. At Earth, it powers magnetic storms and   
   auroras. It's ubiquitous.   
       
   The problem is, researchers can't explain it.   
       
   https://www.youtube.com/watch?v=BGh1xc-O0WA&feature=youtu.be   
       
   A new ScienceCast video previews the MMS mission to study the mysteries of   
   magnetic reconnection. Play it   
       
   The basics are clear enough. Magnetic lines of force cross, cancel, reconnect   
   and-Bang! Magnetic energy is unleashed, with charged-particles flying off near   
   the speed of light. But how? How does the simple act of crisscrossing magnetic   
   field lines trigger such a ferocious explosion?   
       
   "Something very interesting and fundamental is going on that we don't fully   
   understand," says Jim Burch of the Southwest Research Institute.   
       
   NASA is about to launch a mission to get to the bottom of the mystery. It's   
   called MMS, short for "Magnetospheric Multiscale" and it consists of four   
   spacecraft that will fly through Earth's magnetic field, or "magnetosphere,"   
   to study reconnection in action.   
       
   "Earth's magnetosphere is a wonderful natural laboratory for studying this   
   phenomenon," says Burch, the MMS Principal Investigator.   
       
   Slated for launch on March 12th, the four spacecraft were designed, built and   
   tested at NASA's Goddard Space Flight Center. Each one is shaped like a giant   
   hockey puck, about 4 meters in diameter and 1 meter in height.  In space,   
   however, they are much larger.   
       
   http://tinyurl.com/kbbs7ho   
       
   A cartoon model of magnetic reconnection on the sun. [more] "After launch, the   
   spinning spacecraft will unfurl their electromagnetic sensors, which are at   
   the end of wire booms as much as 60 meters long," says Craig Tooley, MMS   
   Project Manager at Goddard.  "When fully extended, the sensors are as wide as   
   a baseball field."   
       
   These sprawling, spinning probes will fly in precise formation, as close as 10   
   km apart and are guided by GPS satellites orbiting Earth far below them. "We   
   can maintain formation with an accuracy of only 100 meters," says Tooley.   
   "This is crucial to our measurements."   
       
   Any new physics MMS observes could help provide clean energy on Earth.   
       
   "For many years, researchers have looked to fusion as a clean and abundant   
   source of energy for our planet," says Burch. "One approach, magnetic   
   confinement fusion, has yielded very promising results with devices such as   
   tokamaks. But there have been problems keeping the plasma contained in the   
   chamber."   
       
   "One of the main problems is magnetic reconnection," he continues. "A   
   spectacular result of reconnection is known as the 'sawtooth crash.' As heat   
   in the tokamak builds up, the electron temperature reaches a peak, then   
   'crashes' to a lower value. Some of the hot plasma escapes. This is caused by   
   reconnection of the containment field."   
       
   In light of this, you might suppose that fusion chambers would be a good place   
   to study reconnection. But no, says Burch. Reconnection in tokamaks happens in   
   a tiny volume only a few centimeters wide. It is practically impossible to   
   build sensors small enough to probe the reconnection zone.   
       
   Earth's magnetosphere is much better. In the expansive magnetic bubble that   
   surrounds our planet, the process plays out over volumes as large as tens of   
   kilometers across, for instance, when reconnection at the sun propels plasma   
   clouds toward Earth, where additional reconnection events then sparks auroras.   
       
   "We can fly spacecraft in and around it and get a good look at what's going   
   on," he says.   
       
   That is what MMS will do: fly directly into the reconnection zone. The   
   spacecraft are sturdy enough to withstand the energetics of reconnection   
   events known to occur in Earth's magnetosphere, so there is nothing standing   
   in the way of a full two-year mission of discovery.   
       
   For more information and updates, visit the MMS home page: www.nasa.gov/mms   
       
   Credits:   
   Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.99   
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