EPSC Abstracts
Vol. 18, EPSC-DPS2025-818, 2025, updated on 09 Jul 2025
https://doi.org/10.5194/epsc-dps2025-818
EPSC-DPS Joint Meeting 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Particle Environment Package (PEP) for the Juice Mission: Current Status
Stas Barabash1, Pontus Brandt2, Peter Wurz3, George Clark2, Markus Fränz4, Donald Mitchel2, Manabu Shimoyama1, Audrey Vorburger3, Martin Wieser1, Elias Roussos4, Gabriella Stenberg Wiesewr1, and the PEP Team*
Stas Barabash et al.
  • 1Swedish Institute of Space Physics, Kiruna, Sweden (stas@irf.se)
  • 2Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
  • 3University of Bern, Bern, Switzerland
  • 4Max Planck Institute for Solar System Research, Göttingen, Germany
  • *A full list of authors appears at the end of the abstract

The Particle Environment Package (PEP) onboard ESA’s Jupiter Icy Moons Explorer (JUICE) provides particle measurements to address three overarching science questions:

  • How does Jupiter’s co-rotating magnetosphere interact with Ganymede, Callisto, Europa, and Io?
  • How do internal and solar wind drivers generate energetic, time-variable, and multi-scale phenomena in Jupiter’s steadily rotating giant magnetosphere?
  • What are the structure and composition of the icy moons’ exospheres, and how do they respond to external conditions?

PEP measures positive and negative ions, electrons, exospheric neutral gas, thermal plasma, and energetic neutral atoms (ENAs) across all domains of the Jupiter system—covering nine decades of energy, from < 0.001 eV to > 1 MeV, with full angular coverage.

The six PEP sensors are:

  • Jovian Plasma Dynamics and Composition Analyzer (JDC)
  • Jovian Electrons and Ions Analyzer (JEI)
  • Jovian Energetic Electrons (JoEE)
  • Jovian Energetic Neutrals and Ions Sensors (JENI)
  • Jovian Neutrals Analyzer (JNA)
  • Neutral Gas and Ion Mass Spectrometer (NIM)

These sensors are grouped into two subsystems:

  • PEP-Lo: JDC, JEI, JNA, NIM (covering low energies up to tens of keV)
  • PEP-Hi: JENI, JoEE (covering up to 1 MeV)

For the first time at Jupiter, PEP combines magnetospheric ENA imaging with in-situ measurements, enabling remote sensing of the Europa and Io tori via ENAs. Using low-energy ENAs produced by particle–surface interactions, PEP investigates space weathering of the icy moons caused by particle precipitation.

PEP directly samples the exospheres of Europa, Ganymede, and Callisto with unprecedented mass resolution (>700).

PEP-Hi (JENI and JoEE), JEI, and JDC are fully commissioned and collected excellent data during the Moon–Earth flyby on 19–20 August 2024.
This presentation overviews the status of the package, collected data so far, sensor performance, and science operations in the Jovian system and during the cruise phase.

PEP Team:

PEP Team

How to cite: Barabash, S., Brandt, P., Wurz, P., Clark, G., Fränz, M., Mitchel, D., Shimoyama, M., Vorburger, A., Wieser, M., Roussos, E., and Stenberg Wiesewr, G. and the PEP Team: Particle Environment Package (PEP) for the Juice Mission: Current Status, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–12 Sep 2025, EPSC-DPS2025-818, https://doi.org/10.5194/epsc-dps2025-818, 2025.