Ubiquitous Nature of Pickup Ions in the Outer Heliosphere and Beyond

Interstellar pickup ions (PUIs) hold most of the internal solar wind pressure and are preferentially accelerated at shocks in the outer heliosphere. In the whitepaper, we briefly present limitation of existing PUI observations and identify related knowledge gaps. We recommend prioritizing a dedicated PUI instrument to observe PUIs in the heliosheath and beyond.