Polarimeter to UNify the Corona and Heliosphere (PUNCH)

Authors: Don Kolinski (High Altitude Observatory, National Center for Atmospheric Research), Craig DeForest (Southwest Research Institute), Sarah Gibson (High Altitude Observatory, National Center for Atmospheric Research), Cherilynn Morrow (Southwest Research Institute - Consultant), Robin Colaninno (U.S. Naval Research Laboratory), Glenn Laurent (Southwest Research Institute), Mary Hanson (University of Colorado), Steve Cranmer (University of Colorado), Curt de Koning (University of Colorado, CIRES/SEC), Mihir Desai (Southwest Research Institute), Heather Elliott (Southwest Research Institute), Anna Malanushenko (High Altitude Observatory, National Center for Atmospheric Research), Barbara Thompson (NASA Goddard Space Flight Center), Nicholeen Viall (NASA Goddard Space Flight Center), David Webb (Boston College), and the PUNCH Team (Southwest Research Institute)

PUNCH is a NASA Small Explorer mission to better understand how the mass and energy of the Sun’s corona become the solar wind that fills the solar system. The mission consists of a constellation of four small satellites in Sun-synchronous, low Earth orbit that together will produce deep-field, continuous, 3D images of the solar corona as it makes a transition to the young solar wind from the outermost solar atmosphere to the inner heliosphere. PUNCH’s science goal is to comprehend cross-scale physical processes of heliophysics, from micro scale turbulence to the evolution of global scale structures. There are six science objectives that span the quiescent and dynamic young solar wind, which will be achieved by activities of six working groups. Through a series of workshops, PUNCH has been engaging the broader solar and heliospheric community to develop tools in anticipation of the data and to grow a broad community of PUNCH users to realize its maximum benefit. An undergraduate student collaboration to search for X-ray signatures of coronal heating mechanisms includes development of another instrument, the Student Thermal Energetic Activity Module (STEAM). Moreover, PUNCH engages interested heliophysicists in a mission-embedded outreach program with an Ancient & Modern Sun Watching theme that is collaborating with underserved and underrepresented populations and connecting to the broader public in the US Southwest and beyond. PUNCH is scheduled to launch in April of 2025.