If all goes well, the Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) probe will launch on May 19 from the European Spaceport in French Guiana. It will use a new technology to map Earth's magnetic field. Earth's magnetic field deflects most of the charged solar particle stream, making Earth habitable. Surges in the solar wind can disrupt satellites, radio communications, and even power grids. SMILE is a China-Europe collaboration project, expected to improve understanding of the relevant physical mechanisms and enhance the ability to predict solar storms. Many probes have detected the magnetosphere, but they can only observe from within it, limited to the positions of each satellite. SMILE will be launched into a highly elliptical orbit, reaching up to 121,000 kilometers above the North Pole. From there, SMILE's core instrument—a soft X-ray imager—will monitor the entire sun-facing edge of the magnetosphere. When charged particles in the solar wind capture electrons from neutral atoms in Earth's upper atmosphere, the electrons emit X-rays as they transition to lower energy levels. By mapping the radiation of the narrow boundary where the solar wind meets the magnetosphere, SMILE will be able to track the response of Earth's magnetic field in near real-time. SMILE's ultraviolet imager will observe auroras—one of nature's most spectacular sights.

https://www.science.org/content/article/chinese-european-mission-reveal-shape-earth-s-magnetic-shield