Federico Fraschetti
Center for Astrophysics, Harvard & Smithsonian
Origin of cosmic rays and approaches of Parker Solar Probe into the young near-Sun solar wind
The NASA mission Parker Solar Probe (PSP) has provided us in the last six years with unprecedented insights about the origin of cosmic rays, via direct measurements of high-energy charged particles in the heliosphere. In its closest approaches to the Sun, as close as 0.05 AU, PSP not only explored the dense and highly magnetized solar wind but also unveiled the early-on phase of particle acceleration and escape at one of the fastest shock wave ever observed in the solar wind; additionally, it revealed unexpected properties of transport through turbulent interplanetary plasmas. I will review some of the key observations, recent modeling efforts and open questions motivating an extended mission.