The heliosphere is permeated with energetic particles of different compositions, energy spectra and origins. Two major particle populations are galactic cosmic rays (GCRs), which originate from outside of the heliosphere and are constantly detected at Earth, and solar energetic particles (SEPs) which are accelerated at/near the Sun during solar flares or by shock fronts associated with the transit of coronal mass ejections. In the solar wind, energetic particle detectors onboard missions such as Solar Orbiter and Parker Solar Probe help us to understand SEP acceleration and transport as they propagate through the heliosphere, whereas instruments such as AMS-02 aboard the ISS and ground-based neutron monitors can provide information on GCR transport through the heliosphere. High fluxes of energetic particles, such as from SEP events, can pose a severe radiation risk to crewed spaceflight and a significant threat to satellites. Particle precipitation has also been shown to cause changes in the chemistry of the middle and upper layers of the Earth's atmosphere, thermodynamic effects in the upper troposphere and lower stratosphere region, and can influence components of the global electric circuit. This session will aim to address the acceleration of energetic particles, their transport through the heliosphere, their detection at Earth and the planets and the effects they have on the atmosphere, humans and human technology when they arrive. It will bring together scientists from several fields of research in what is now very much an interdisciplinary area, and promote discussion and collaboration between them. The session will allow sharing of expertise amongst international researchers as well as showcase the recent advances being made in this field, which demonstrate the importance of the study of these energetic particle populations