The Polarimeter to UNify the Corona and Heliosphere (PUNCH) Small Explorer Mission: Status and Next Steps

Abstract:

The Polarimeter to UNify the Corona and Heliosphere (PUNCH) is a NASA Small Explorer mission, to understand the solar corona and young solar wind as a complete system. Science objectives are to measure and understand how the ambient solar wind arises from the corona, and to understand how transient events (such as CMEs) propagate and evolve in the inner heliosphere. PUNCH uses direct, global, spatially continuous, three dimensional imaging in polarized visible light, to observe the outer corona and inner heliosphere as elements of a single, connected system. PUNCH comprises four matched and synchronized small-satellite observatories, operating as a "virtual instrument" to image Thomson-scattered light from low-Earth orbit. PUNCH is the first coronal and solar wind imaging mission designed specifically to produce 3D images from a single vantage point using the polarization properties of Thomson scattering. In addition, it will produce routine, several-times-per-day maps of solar wind flow throughout the top of the corona and bottom of the inner heliosphere, based on motion analysis of the image stream. PUNCH has an open data policy and is seeking scientific engagement throughout the heliophysics community.

PUNCH is wrapping up its Phase B (preliminary design), and is working toward a 2023 launch for a two-year nominal mission. We present a very brief overview of the mission, describe current status and next steps, and indicate how to engage with the PUNCH science team and upcoming mission.