Authors: Pontus C. Brandt (Johns Hopkins APL, MD, USA), Andrew R. Poppe (UC Berkeley, CA, USA), Merav Opher, (Boston University, MA, USA), Matt E. Hill, (Johns Hopkins APL, MD, USA), Heather A. Elliott, (SwRI, TX, USA), Romina Nikoukar (Johns Hopkins APL, MD, USA), Peter Kollmann (Johns Hopkins APL, MD, USA), Parisa Mostafavi (Johns Hopkins APL, MD, USA), Ralph L. McNutt, Johns Hopkins APL, MD, USA), Elena Provornikova (Johns Hopkins APL, MD, USA), Pawel Swaczyna (Space Research Centre PAS, Poland), Malgorzata Antonik (Space Research Centre PAS, Poland), Fran Bagenal (LASP, Boulder, CO, USA), Erick Powell (Boston University, MA, USA), Justyna Sokol (SwRI, TX, USA), David J. McComas (Princeton University, NJ, USA), Kostas Dialynas (Academy of Athens, Greece), Bishwas Shrestha (Princeton University, NJ, USA), Eric Zirnstein (UAH, AL, USA), S. Alan Stern (SwRI, CO, USA), Kelsi N. Singer (SwRI, CO, USA), Anne Verbiscer (SwRI, CO, USA), Joel W. Parker (SwRI, CO, USA), Tracy Becker (SwRI, TX, USA), Mihaly Horanyi (LASP, CO, USA), Will Grundy (Lowell Observatory, AZ, USA), Susan Bennecchi (PSI, USA)

NASA’s New Horizons spacecraft is currently at 65 au from the Sun, where the SWAP and PEPSSI particle and plasma spectrometers make the only interstellar pick-up ion (PUI; H⁺ and He⁺) measurements in the outer heliosphere together with solar wind, energetic particle, and galactic cosmic ray (GCR) data. Projected to have sufficient power to operate to 2050, the mission can provide measurements through the outer heliosphere, termination shock, heliosheath and ultimately through the heliopause to about 135 astronomical units (au) from the Sun.

Interstellar PUIs dominate the internal pressure of the solar wind past 10 au and control the plasma thermodynamics in the heliosheath – the 30-au thick boundary region to interstellar space that shields the inner heliosphere from the local interstellar medium and GCRs.

Despite their decisive importance for the global heliosphere, PUIs have never previously been measured in the heliosheath or in the local interstellar medium. This has prevented physics-driven global models of the heliosphere from making necessary progress and is leaving important questions open such as the thickness of the heliosheath, morphology of the heliosphere, origin of turbulence, shock acceleration and more. Additionally, New Horizons continues to be a vital component of the Heliophysics System Observatory (HSO), in particular as it is the only platform in the outer heliosphere that can connect how CMEs and CIRs propagate and merge throughout the heliosphere, investigate how the heliosheath filters GCRs, and make in-situ measurements at the same time as IMAP is remotely imaging that region using energetic neutral atoms.

The NASA Planetary Science Division (PSD) has predominantly funded New Horizons over the past two decades. As heliophysics data are now becoming an increasing part of the mission’s activities and value, NASA PSD is requesting the Heliophysics Division (HPD) to contribute to the data collection and downlink cost. In order to demonstrate the value of the New Horizons heliophysics data to HPD to justify the cost sharing, the team will be calling on the science community to show their support through a signed letter.

This presentation provides an overview of the heliophysics investigations conducted from New Horizons. At the same time, it provides a forum to discuss the specific values to the community, HPD and to the HSO.