Today, NASA is set to launch an array of four satellites that will fly in a pyramid-shaped formation — to produce a 3D image of how the magnetic fields of solar winds collide with the magnetic field of earth.

From the New York Times:

The protective bubble of the Earth's magnetic field typically deflects high-speed particles from the sun. But an onslaught of particles from a solar explosion can pop the outer layers of the bubble. "Right where the solar wind meets the magnetosphere, that boundary, you have a weak point in the magnetic field," Dr. Dorelli said. The details of the popping, known as magnetic reconnection, remain mysterious. (The same process, on a much larger scale, generates the solar explosions known as coronal mass ejections.)

Here's a good NASA video about the mission, opening with a cool animation of what the satellites will look like while flying in formation: