Chasing Shocks with Solar Orbiter: Insights into Particle Acceleration During Solar Cycle 25

Interplanetary (IP) shock waves propagate through the heliosphere as a result of solar activity. These shocks are key sites of energy conversion and particle acceleration and can be observed in situ through spacecraft measurements, providing a unique link to remote astrophysical environments and an excellent “natural laboratory” for testing still-debated acceleration mechanisms.

The current fleet of heliospheric observers offers an unprecedented opportunity to study IP shocks, marking a “new golden era” for understanding their role in heliospheric energetics. In particular, Solar Orbiter provides high-resolution measurements in the suprathermal (above ~50 keV) range, opening a new observational window on how particles are accelerated out of the thermal population.

In addition to presenting the statistical properties and trends of Solar Orbiter IP shocks up to the solar maximum of cycle 25, I will showcase specific events that uncovered new aspects of energetic particle production. I will show how leveraging state-of-the-art numerical simulations alongside multi-spacecraft observations makes it possible to probe the fundamental physics driving these acceleration processes in unprecedented detail. Together, these results offer fresh insights into how shocks energize particles across both heliospheric and astrophysical environments.