At it's most basic, magnetic reconnection occurs when two field lines come together and realign into a new configuration. It happens all over the universe and is the catalyst for aurora near Earth, giant explosions on the sun such as solar flares, and even giant jets streaming out of supernovae.
Magnetic reconnection also can have an impact on humans. Magnetic reconnection is what allows energy and material from the sun to break through the boundaries of Earth's protective magnetic bubble, the magnetosphere, into near-Earth space. That energy and solar material can lead to a whole host of space weather effects, which can disrupt radio communications, interfere with satellite electronics or even affect utility power grids on the ground.
Although this phenomenon happens rarely on Earth, it is much less rare in Earth's own magnetosphere, an ideal natural laboratory in which reconnection can be observed under a wide range of conditions. Scientists want to know exactly what conditions, what tipping points, trigger magnetic reconnection events. Much of what we currently know about the small-scale physics of magnetic reconnection comes from theoretical studies, computer models, and laboratory experiments. True understanding, however, requires observing magnetic reconnection up close...
The Magnetospheric Multiscale Mission, or MMS for short, is a Solar Terrestrial Probes mission comprised of four identically instrumented spacecraft that measure plasmas, fields, and particles in a near-equatorial orbit that will frequently encounter reconnection in action. MMS reveals, for the first time, the small-scale three-dimensional structure and dynamics of the elusively thin and fast-moving electron diffusion region. It does this in both of the key reconnection regions near Earth, where the most energetic events originate.
If you missed the live coverage of the Magnetospheric Multiscale Mission launch we've got you covered! NASA EDGE will host a pre-recorded version of this webcast just as soon as they can. It's just like you're there! The mission successfully launched on March 12, 2015 at 10:44pm EST. NASA EDGE USTREAM channel
There is a lot of great information about the MMS mission, and we have compiled a great list of resources for you to explore.
A typical CME can be millions of kilometers in size, but have the mass of only a small mountain!