A comprehensive study from the Sun to the Earth of the Space Weather event starting on the 6 September 2017

It is well known that Space Weather events can have a profound impact on our technology-dependent society. On September 6, 2017, a powerful Space Weather event originated on the Sun in the active region 12673 located at 9 degrees North latitude and 42 degrees West longitude.  An X9.3 class flare was produced, peaking at 12:02 UT, and was associated with a powerful eruptive coronal mass ejection and the emission of solar energetic particles. Correspondingly, several phenomena were observed in the interplanetary space and Earth’s environment on September 7: a shock passage at 22.58 UT associated with an energetic particle enhancement, followed by magnetospheric compression, plasmasphere density depletion, ionospheric storm and intensification of convection cells, and a Forbush decrease in the cosmic ray intensity. Here we provide a comprehensive understanding of the event, encompassing the whole chain of phenomena occurred from the Sun to the Earth. We explore the causes and evolution the Space Weather event and evaluate effects on technological systems as well as  implications for future space weather research.