Auroral responses to the visit of comet 73P/Schwassmann–Wachmann 3 in 2006

The stunning tails of comets are interesting astronomical phenomena to human beings and have been noticed for thousands of years. The bright tails also emit substantial materials into interplanetary space, including dusts and charged particles. The charged particles are picked up by solar wind magnetic fields, and thus could propagate together with solar wind to influence planetary space environments. Simultaneous measurements of comet materials, planetary space, and ground environments are crucial for understanding cometary impacts to planets, while such observations are quite rare. In this article, we present a full chain from the comet tail, to the solar wind cometary particles, and the impacts on the ground. Intense auroral events are observed when the cometary materials are observed in the Earthʼs upstream solar wind. Our results provide direct evidence that cometary ions could contribute substantial dynamic pressure in driving geomagnetic activities and the associated auroral intensifications.