PUNCH primary science goal is to fully discern the cross-scale physical processes - from microscale turbulence to the evolution of global-scale structures - that unify the solar corona and heliosphere.
How does the solar corona become the solar wind? The currently unexplored region spanning the outer corona and the inner heliosphere (the young solar wind) represents a fundamental gap in our understanding of the Sun-Earth connection. It is critical that we bridge this gap if we are ever to understand the Sun and heliosphere as a single system, or to understand the origin and nature of Earth-impacting structures. Although the ultimate source of these structures is the solar corona, both evolution and interactions with the solar wind occur en route to Earth, and substructures may form and change via plasma instabilities and turbulence in the solar wind.
PUNCH eliminates the blind spots between coronal and heliospheric imagers and at the poles, continuously observing the young solar wind with a global field of view. PUNCH integrates images from its constellation of small satellites into a global composite each orbit, covering ~6 orders of magnitude dynamic range. Through a stream of these high-cadence, low-noise, global polarized images in broadband visible light, PUNCH achieves 3D feature localization and unprecedented deep field imaging (Deforest & Howard, 2015).