The wrapping of our planet and the protection against harmful solar wind is an invisible magnetic field. Solar wind is a stream of plasma or charged particles, such as protons and electrons, released from the outer layers of the sun. Without the magnetic field, the solar wind could destroy the atmosphere of our planet and make it habitable.
But how does this process work? For the first time, researchers explain how the earth's magnetic field pushes the strong solar wind without damage. As the earth moves around the sun, it creates an arc-shaped wave or arc shock in front of itself, similar to a moving motorboat. When the electrons hit the bow thrust in the solar wind, their velocity is momentarily accelerated so that the electron current becomes unstable and collapses. This interaction slows down electrons and converts the energy into heat.
"If you were standing on a mountaintop, you might be knocked over by a fast wind," said lead author Li-Jen Chen of the University of Maryland. "Fortunately, the bow shock protects us when the solar wind plunges into the earth's magnetic field, slowing that wind and turning it into a pleasant, warm breeze." We now have a better idea of it. "
The result is based on data from NASA's Magnetospheric Multiscale (MMS) mission. The MMS mission consists of four identical satellites that study the earth's magnetic field interacting with the solar wind and perform three-dimensional measurements every 30 milliseconds. The data help researchers better understand the role of the magnetic field around the Earth.
"These extremely fast measurements of MMS finally allowed us to see the electron-warming process in the thin shock layer," said co-author Thomas Moore of the Goddard Space at the NASA Flight Center. "This is groundbreaking because we now have the ability to identify the mechanism at work rather than just watching its consequences."
During the mission, the researchers observed the solar wind electron before, during, and after encountering the bow shock, and found out that it took only 90 milliseconds for Bogenschock to destabilize and deplete electrons.
"The new observations of electron acceleration at the bow are shocking the current understanding of electron warming, for example, researchers did not expect the arc kick to do so. 2 / index.html The electron heat study is important, not only to understand how the arc shock protects the Earth, but possibly also about satellites, space travel, and other planets in the region's future. "