Tracking an interplanetary coronal mass ejection through the solar system

A large interplanetary coronal mass ejection (ICME) was ejected at the Sun on 14 October 2014. Ten spacecraft, from ESA's Venus Express to NASA's Voyager-2, felt the effect of this solar eruption as it washed through the Solar System. Three Solar observatories watched the Sun, providing a unique perspective on this space weather event (Witasse, O. et al., Interplanetary coronal mass ejection observed at STEREO-A, Mars,comet67P/Churyumov-Gerasimenko, Saturn, and New Horizons en route to Pluto: Comparison of its Forbush decreases at 1.4, 3.1, and 9.9 AU, J. Geophys. Res. Space Physics, 122, doi:10.1002/2017JA023884). In this short overview, we will explain what triggered such an unusual study, describe the data sets that were analyzed, and the use of modelling tools. We will outline the importance of providing the space weather context for interpretation of planetary plasma data, and of gathering expertise from colleagues who belong to different communities. Eventually, we will promote the use of engineering data in heliophysics studies.