Colloquium: Jamie Rankin, Princeton University
From Interstellar Space to the Sun’s Embrace: Cosmic Ray Journeys through the Heliosphere
Event Details
- Date: December 2, 2025
- Time: 3:45 - 4:45 PM
- Location: 1080 Physics Research Building
- Faculty Host: John Beacom
Abstract
Over a century since their discovery, cosmic rays remain a compelling subject of inquiry in the fields of particle and space physics. These fully ionized atomic nuclei – comprised of practically all known elements of the periodic table – trace paths through the galaxy (and in some cases, from beyond) that cover vast spatial distances, and span over fourteen decades in energy (~MeV to few hundred EeV observed so far). Although origins at all scales are still not fully understood, the last decade has led to some especially critical breakthroughs, particularly towards understanding their transport and acceleration. This talk focuses on key insights primarily gained from space-based observations of cosmic rays, ranging from ~MeV to ~TeV, whose trajectories get modified by the dynamics and presence of our own stellar astrosphere, the “heliosphere”. It will survey the key findings derived from in-situ measurements at various locations throughout the solar system – including those at record-setting distances far and near to the Sun (from the Voyagers to Parker Solar Probe) – and venture beyond the cosmic rays themselves to emphasize what they reveal about how the Sun interacts with its surrounding interstellar environment, the size and structure of the heliosphere, and the physics of particle-plasma interactions applicable to many solar and astrophysical phenomena.
Bio
Biography from Space Physics at Princeton