EGUsphere EGUsphere EGUsphere EGUsphere Copernicus Publications Göttingen, Germany 10.5194/egusphere-2026-4440 Dust in the Inner Heliosphere Zaslavsky Arnaud https://orcid.org/0000-0001-8543-9431 1 25 Mann Ingrid B. https://orcid.org/0000-0002-2805-3265 2 25 Howard Russel A. 3 Sternovsky Zoltan https://orcid.org/0000-0002-9658-1350 4 5 Anghel Simon https://orcid.org/0000-0001-5047-574X 6 Kvammen Andreas https://orcid.org/0000-0002-5511-4473 2 Malaspina David M. 4 7 Meyer-Vernet Nicole https://orcid.org/0000-0001-6449-5274 1 Pantellini Filippo https://orcid.org/0000-0002-1689-8893 1 Pérrone Arthur 8 Rackovic-Babic Kristina 9 Sterken Veerle J. 10 8 Szalay Jamey R. https://orcid.org/0000-0003-2685-9801 11 Bale Stuart D. https://orcid.org/0000-0002-1989-3596 12 13 14 Bothmer Volker 15 24 DeForest Craig E. 16 Gasque L. Claire https://orcid.org/0000-0002-9000-7630 13 Ishimaru Ryo 17 Kimura Hiroshi 17 Maksimovic Milan https://orcid.org/0000-0001-6172-5062 1 Morooka Michiko 18 Nieves-Chinchilla Teresa https://orcid.org/0000-0003-0565-4890 19 Nouzák Libor 20 Píša David https://orcid.org/0000-0002-1322-7576 21 Pokorný Petr https://orcid.org/0000-0002-5667-9337 22 23 Raouafi Nour E. 3 Shen Mitchell M. https://orcid.org/0000-0002-3093-458X 11 Smith Austin Matheus https://orcid.org/0009-0001-5822-9735 4 5 Stenborg Guillermo 3 LIRA, Observatoire de Paris, Université PSL, Sorbonne Université, Université Paris Cité, CY Cergy Paris Université, CNRS, 5 Place Jules Janssen, 92190 Meudon, France Department of Physics and Technology, The Arctic University of Norway, Postboks 6050 Langnes, 9037 Tromsø, Norway The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, USA Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, Boulder, CO 80303, USA Smead Aerospace Engineering Sciences Department, University of Colorado at Boulder, Boulder, CO 80303, USA LTE, Observatoire de Paris, Université PSL, Sorbonne Université, Université de Lille, LNE, CNRS, 61 Avenue de l’Observatoire, 75014 Paris, France Astrophysical and Planetary Sciences, University of Colorado, Boulder, Boulder, CO 80303, USA Institute for Particle and Astroparticle Physics, ETH Zurich, Wolfgang-Pauli-strasse 27, 8093 Zürich, Switzerland LPC2E, CNRS, Université d’Orléans, CNES, 3A Avenue de la Recherche Scientifique, 45071 Orléans, France Institute of Physics, Laboratory of Astrophysics (LASTRO), Ecole Polytechnique Federale de Lausanne (EPFL), Observatoire de Sauverny, CH-1290 Versoix, Switzerland Department of Astrophysical Sciences, Princeton University, 4 Ivy Ln., Princeton, NJ 08540, USA Physics Department, University of California, Berkeley, Berkeley, CA 94720-7300, USA Space Sciences Laboratory, University of California, Berkeley, Berkeley, CA 94720-7450, USA The Blackett Laboratory, Imperial College London, London SW7 2AZ, UK Institute for Astrophysics and Geophysics, University of Göttingen, Friedrich-Hund-Pl.1, 37077 Göttingen, Germany Solar System Science and Exploration Division, Southwest Research Institute, Boulder, CO, 80302, USA Planetary Exploration Research Center (PERC), Chiba Institute of Technology, Tsudanuma 2-17-1, Narashino, Chiba 275-0016, Japan Swedish Institute of Space Physics, Uppsala, Box 537, SE-751 21 Uppsala, Sweden Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA Department of Surface and Plasma Science, Charles University, 180 00 Prague, Czech Republic Department of Space Physics, Institute of Atmospheric Physics of the Czech Academy of Sciences, 141 00 Prague, Czechia Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA Department of Physics, The Catholic University of America, Washington, DC 20064, USA deceased, 23 april 2026 These authors contributed equally to this work. 17 08 2026 2026 1 80 Copyright: © 2026 Arnaud Zaslavsky et al. 2026 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-4440/ The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-4440/egusphere-2026-4440.pdf

The inner heliosphere hosts a dynamically rich population of dust particles – the Zodiacal Dust Cloud – spanning sizes from nanometers to hundreds of micrometers and originating primarily from comets and asteroids. Over the past two decades, a generation of space missions has transformed our observational grasp of this environment. This review consolidates the advances enabled by the Wind, STEREO, Parker Solar Probe, and Solar Orbiter space missions, which together observe from heliocentric distances of 1 au down to less than 0.05 au. Two complementary observational approaches are addressed in detail. The first is in-situ dust detection via radio and plasma wave instruments, which commonly measure characteristic voltage pulses resulting from hypervelocity dust impacts on spacecraft. We describe the underlying physics, signal interpretation, dust particle mass calibration and machine-learning classification methods for this technique, which constitutes the only in-situ dust measurement capability on current inner-heliosphere missions. The second approach is remote sensing of the Zodiacal Light and F-corona through white-light coronagraph and heliospheric imagers. The combination of these approaches has yielded a consistent picture of the radial brightness profile of the cloud, provided the first observational evidence for a dust depletion zone developing sunward of 35 solar radii and a dust-free zone interior to 5 solar radii. The in-situ measurements established flux densities of dust in hyperbolic trajectories (β-meteoroids) across multiple missions, revealed variable fluxes of nanodust, and revealed solar-cycle modulation of the interstellar dust flux. This review presents these results, discusses their implications, and outlines the prospects offered by near-future missions.