Magnetic fields of Earth and Sun: Space mission
Space is a better vacuum than any we can create on Earth, but it does contain some particles—and it’s bustling with activity. It overflows with energy and a complex system of magnetic fields. Sometimes, when two sets of magnetic fields connect, an explosive reaction occurs: As the magnetic fields re-align and snap into a new formation they send particles zooming off in jets.
A new paper printed on May 12, 2016, in Science provides the first observations from inside a magnetic reconnection event. The research shows that magnetic reconnection is dominated by the physics of electrons—thus providing crucial information about what powers this fundamental process in nature.
The effects of this sudden release of particles and energy—such as giant eruptions on the sun, the aurora, radiation storms in near-Earth space, high energy cosmic particles that come from other galaxies—have been observed throughout the solar system and beyond. But we have never been able to witness the phenomenon of magnetic reconnection directly. Satellites have observed tantalizing glances of particles speeding by, but not the impetus—like seeing the debris flung out from a tornado, but never seeing the storm itself.
“We developed a mission, the Magnetospheric Multiscale mission, that for the first time would have the precision needed to gather observations in the heart of magnetic reconnection,” said Jim Burch, the principal investigator for MMS at the Southwest Research Institute in San Antonio, Texas, and the first author of the Science paper. “We received results faster than we could have expected. By seeing magnetic reconnection in action, we have observed one of the fundamental forces of nature.”
MMS is made of four identical spacecraft that launched in March 2015. They fly in a pyramid formation to create a full 3-D map of any phenomena they observe. On Oct. 16, 2015, the spacecraft traveled straight through a magnetic reconnection event at the boundary where Earth’s magnetic field bumps up against the sun’s magnetic field. In only a few seconds, the 25 sensors on each of the spacecraft collected thousands of observations. This unprecedented time cadence opened the door for scientists to track better than ever before how the magnetic and electric fields changed, as well as the speeds and direction of the various charged particles.
