Caption: 
Using data from NASA’s Parker Solar Probe, an SwRI-led team identified low-energy particles, the smoking gun pointing to interactions between slow- and fast-moving regions of the solar wind accelerating high-energy particles from beyond the orbit of Earth. Using Integrated Science Investigation of the Sun (IS☉IS) instrument data, they measured low-energy particles in the near-Sun environment that had likely traveled back toward the Sun, slowing against the tide of the solar wind while still retaining surprising energies.

Credit: 
Courtesy of NASA/Johns Hopkins APL/Steve Gribben