After 10 years of challenging development, the four identical spacecraft of the Magnetospheric Multiscale (MMS) mission spacecraft launched in 2015. They are now flying in a tighter and tighter formation to reveal the microphysics of our space environment, including the dynamic phenomenon of “magnetic reconnection” in the magnetic fields surrounding Earth. MMS provides unprecedentedly fast observations – at 30 images per second — showing the first-ever three-dimensional views of magnetic reconnection, in which magnetic fields come together and explosively release energy and send particles in all directions. MMS observations began with the spacecraft 160 kilometers (100 miles) apart and have progressed as they closed to just 10 kilometers (6 miles) apart.
In preparation for a host of ground-breaking results expected in 2016, on December 17 a panel of MMS team members will discuss early results from the mission, explain what happens when reconnection joins the sun’s magnetic field with Earth’s and why we need four ultrahigh-resolution spacecraft flying in formation to learn how reconnection works.
Katherine Goodrich, a graduate student at the University of Colorado Boulder, is working with measurements from a suite of six instruments to characterize the behavior of electric and magnetic fields at magnetic reconnection sites. This suite of instruments, the FIELDS suite — duplicated on each of the four MMS spacecraft — contains six sensors that work together to form a three-dimensional picture of the electric and magnetic fields near the spacecraft. This suite has a very high accuracy, in part due to the very long booms on each sensor.
“The long booms allow us to measure the fields with minimal contamination from the electronics aboard the spacecraft,” said Goodrich. Along the spin plane, the booms measure 400 feet from end to end — longer than a regulation soccer field. The booms on the axis of spin measure 100 feet from end to end.
Using FIELDS observations, Goodrich is looking for one of the smoking guns of magnetic reconnection, called a parallel electric field.
“What we’re looking for is an alignment of electric and magnetic fields,” said Goodrich. “This condition is impossible with a simplified understanding of plasma, but magnetic reconnection is anything but simple.”