Zirnstein, Eric J.Kumar, R.Shrestha, Bishwas L.Swaczyna, PawełDayeh, Maher A.Heerikhuisen, JacobSzalay, J R.2026-06-222026-06-222025Zirnstein, E. J., Kumar, R., Shrestha, B. L., Swaczyna, P., Dayeh, M. A., Heerikhuisen, J., & Szalay, J. R. (2025). Global heliospheric termination shock strength in the solar–interstellar interaction. Nature Astronomy, 9(10), 1495-1510. https://doi.org/10.1038/s41550-025-02634-32397-3366https://hdl.handle.net/10289/18399A heliospheric termination shock (HTS) surrounds our Solar System at approximately 100 astronomical units from the Sun, where the expanding solar wind (SW) is compressed and heated before encountering the interstellar medium. HTS-accelerated particles govern the pressure balance with the interstellar medium, but little is known about the global properties of the HTS beyond in situ measurements from Voyager in only two directions of the sky. Here we fill this gap by extracting the HTS strength using particle-in-cell, test particle and magnetohydrodynamic simulations, constrained by Interstellar Boundary Explorer observations of energetic neutral atoms produced from HTS-accelerated particles. Our results reveal there is a higher compression near the poles during solar minimum compared with solar maximum due to the higher Mach number flow. North–south asymmetries arise from the disparate evolution of the polar coronal holes, while minimum compression near the flanks is probably due to SW slowing from mass loading over a greater distance to the HTS. The results imply a strong connection between the HTS strength and the SW and interstellar medium dynamics.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/mathematicsAstrophysical plasmasSpace physicsTheoretical particle physicsJournal Article10.1038/s41550-025-02634-32397-33665101 Astronomical Sciences51 Physical Sciences5101 Astronomical sciences5107 Particle and high energy physics5109 Space sciences