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WASHINGTON, March 12 (UPI) -- NASA's Magnetospheric Multiscale, or MMS, mission is all set to initiate the first up-close study of Earth's magnetosphere, a shield of charged particles controlled by Earth's magnetic field.
More specifically, the four spacecraft -- set to launch Friday evening, March 12 -- will study how Earth's magnetosphere interacts with charged particles delivered by the sun, and the phenomenon researchers are most interested in studying is magnetic reconnection.
Magnetic reconnection is the process by which crisscrossed streams of electromagnetically charged particles violently realign. These magnetic explosions happen regularly on the surface of the sun, fueling solar flares, coronal mass ejections and similar phenomena.
But magnetic reconnection also occasionally happens on Earth, or just outside it -- in the magnetosphere.
Typically, when solar energy is launched toward Earth, the streams of electromagnetic particles collide with Earth's magnetic field lines while aligned in the same direction. This directional agreement generally allows for a rather gentle collision.
On July 14, 2012, that was not the case, however. The magnetic field lines inside a CME launched from the sun just two days earlier arrived at Earth's magnetosphere aligned in the opposite direction. As a result, an explosive reconnection event occurred.
"During this period of repeated magnetic reconnection, surges of solar material breached the magnetosphere, zooming into near-Earth space," NASA officials explained in a press release about the planned mission.
"Such space weather events can compress the front of the magnetosphere so satellites are left exposed to the more harsh radiation outside the magnetosphere," NASA officials continued. "The magnetic variation can also initiate electric currents flowing through grid lines on Earth, with the potential to damage transformers and disrupt utility power grids."
The four MMS spacecraft orbiting Earth will spend more than a year in the nose of the magnetosphere before moving to study the magnetotail -- observing field lines in both regions to collect data that will enable scientists to build a 3-D model of the magnetic reconnection process.
The four observatory probes will be stacked and launched simultaneously on Friday night via an Atlas V rocket. Takeoff is scheduled for March 12, 2015, at 10:44 p.m. EDT. A live broadcast via NASA Edge will begin at at 9:15 p.m.
