NASA spacecraft discovers new magnetic process in turbulent space

A new type of magnetic event in our near-Earth environment.

In a turbulent magnetic environment, magnetic field lines become scrambled. As the field lines cross, intense electric currents (shown here as bright regions) form and eventually trigger magnetic reconnection (indicated by a flash), which is an explosive event that releases magnetic energy accumulated in the current layers and ejects high-speed bi-directional jets of electrons. Credit: NASA Goddard’s Conceptual Image Lab/Lisa Poje; Simulations by: University of Chicago/Colby Haggerty; University of Delaware/Tulasi Parashar
In a turbulent magnetic environment, magnetic field lines become scrambled. As the field lines cross, intense electric currents (shown here as bright regions) form and eventually trigger magnetic reconnection (indicated by a flash), which is an explosive event that releases magnetic energy accumulated in the current layers and ejects high-speed bi-directional jets of electrons. Credit: NASA Goddard’s Conceptual Image Lab/Lisa Poje; Simulations by: University of Chicago/Colby Haggerty; University of Delaware/Tulasi Parashar

The space immediately around Earth is full of hidden secrets and invisible processes. In a new discovery, NASA’s Magnetospheric Multiscale spacecraft — MMS has captured a new type of magnetic event in our near-Earth environment.

The magnetic event, a foremost process in space involves plasma, dissipates magnetic energy and propels charged particles. Both contribute to a dynamic space weather system. Scientists actually want to study that weather system as like terrestrial weather.

Reconnection happens when crossed attractive field lines snap, dangerously tossing without end adjacent particles at high speeds. Using an innovative technique to squeeze extra information out of the data, the spacecraft discovered reconnection where it has never been seen before — in turbulent plasma.

With the new method, the MMS scientists are hopeful they can comb back through existing datasets to find more of these events, and potentially other unexpected discoveries as well.

The spacecraft found the event in a region called the magnetosheath, just outside the outer boundary of the magnetosphere, where the solar wind is extremely turbulent.

Tai Phan, a senior fellow at the University of California, Berkeley, and lead author on the paper said, “In the plasma universe, there are two important phenomena: magnetic reconnection and turbulence. This discovery bridges these two processes.”

MMS uses four identical spacecraft flying in a pyramid formation to study magnetic reconnection around Earth in three dimensions. Since it flies unfathomably near one another — at a normal partition of only four-and-a-half miles, they hold the record for the nearest division of any multi-rocket development — they can watch wonders nobody has seen previously.

The spacecraft’s instruments are actually designed to capture data at speeds a hundred times faster than previous missions. They are still too ease back to catch turbulent reconnection in action, which requires observing narrow layers of fast-moving particles hurled by the recoiling field lines.

Jonathan Eastwood, a lecturer at Imperial College said, “The smoking gun evidence is to measure oppositely directed electron jets at the same time, and the four MMS spacecraft were lucky to corner the reconnection site and detect both jets.”

Amy Rager, a graduate student at NASA’s Goddard Space Flight Center in Greenbelt, Maryland said, “The key event of the paper happens in only 45 milliseconds. This would be one data point with the basic data. But instead, we can get six to seven data points in that region with this method, allowing us to understand what is happening.”

The finding of reconnection in turbulence has implications, for example, for studies on the Sun. It may help scientists understand the role magnetic reconnection plays in heating the inexplicably hot solar corona — the Sun’s outer atmosphere — and accelerating the supersonic solar wind.

The discovery is reported in the journal Nature.