We present evidence of geomagnetic storms in Mercury’s magnetosphere based on MESSENGER magnetic field observations made just before the probe impacted the planet.Our findings answer the question of whether geomagnet...We present evidence of geomagnetic storms in Mercury’s magnetosphere based on MESSENGER magnetic field observations made just before the probe impacted the planet.Our findings answer the question of whether geomagnetic storms can occur in other planetary magnetospheres.The interaction of the solar wind with Mercury’s magnetosphere is known to involve flux transfer events in the dayside magnetosphere,plasmoids and flux ropes in the magnetotail,and substorm-like processes,all of which occur morphologically similar to Earth but with significant differences.The significantly weaker magnetic field,smaller magnetosphere,and much faster timescale of processes around Mercury,when compared with Earth,enable charged particles to escape its magnetosphere more efficiently through magnetopause shadowing and direct bombard of the surface.Our analysis of MESSENGER’s data during a coronal mass ejection(CME)proves that,despite these substantial differences,a bifurcated ring current can form in Mercury’s magnetosphere that initiates magnetic storms under strong solar wind driving.展开更多
基金supported by Major Project of Chinese National Programs for Fundamental Research and Development(Grant No.2021YFA0718600)China Space Agency Project(Grant No.D020301)+2 种基金the National Natural Science Foundation of China(Grant No.42011530080)financial support from the Canadian Space Agency and NSERCpartially supported by National Science Foundation(Grant No.AGS-1352669)。
文摘We present evidence of geomagnetic storms in Mercury’s magnetosphere based on MESSENGER magnetic field observations made just before the probe impacted the planet.Our findings answer the question of whether geomagnetic storms can occur in other planetary magnetospheres.The interaction of the solar wind with Mercury’s magnetosphere is known to involve flux transfer events in the dayside magnetosphere,plasmoids and flux ropes in the magnetotail,and substorm-like processes,all of which occur morphologically similar to Earth but with significant differences.The significantly weaker magnetic field,smaller magnetosphere,and much faster timescale of processes around Mercury,when compared with Earth,enable charged particles to escape its magnetosphere more efficiently through magnetopause shadowing and direct bombard of the surface.Our analysis of MESSENGER’s data during a coronal mass ejection(CME)proves that,despite these substantial differences,a bifurcated ring current can form in Mercury’s magnetosphere that initiates magnetic storms under strong solar wind driving.
