Scientists have discovered a new type of magnetic event in our near-Earth environment, by using data provided by a NASA spacecraft...
Scientists have discovered a new type of magnetic event in our near-Earth environment, by using data provided by a NASA spacecraft. Magnetic reconnection is one of the most important processes in the space - filled with charged particles known as plasma - around Earth, said researchers at the University of California, Berkeley in the US. This fundamental process dissipates magnetic energy and propels charged particles, both of which contribute to a dynamic space weather system that scientists want to better understand, and even someday predict, as we do terrestrial weather. Reconnection occurs when crossed magnetic field lines snap, explosively flinging away nearby particles at high speeds. The new discovery, published in the journal Nature, found reconnection where it has never been seen before - in turbulent plasma. In the plasma universe, there are two important phenomena: magnetic reconnection and turbulence. This discovery bridges these two processes, said Tai Phan, a senior fellow at the University of California, Berkeley. Magnetic reconnection has been observed innumerable times in the magnetosphere - the magnetic environment around Earth - but usually under calm conditions.
NASA spacecraft discovers new magnetic process in turbulent space
The new event occurred in a region called the magnetosheath, just outside the outer boundary of the magnetosphere, where the solar wind is extremely turbulent. NASA's Magnetospheric Multiscale spacecraft (MMS) uses four identical spacecraft flying in a pyramid formation to study magnetic reconnection around Earth in three dimensions. Since the spacecraft fly incredibly close together - at an average separation of just four-and-a-half miles, they hold the record for closest separation of any multi-spacecraft formation - they are able to observe phenomena no one has seen before. MMS's instruments are designed to capture data at speeds a hundred times faster than previous missions. Even though the instruments aboard MMS are incredibly fast, they are still too slow to capture turbulent reconnection in action, which requires observing narrow layers of fast-moving particles hurled by the recoiling field lines. MMS scientists were able to leverage the design of one instrument, the Fast Plasma Investigation, to create a technique to interpolate the data - essentially allowing them to read between the lines and gather extra data points - in order to resolve the jets.
