SH019-08
Interstellar Probe Measurements of Dust in Our Heliosphere
Wednesday, 9 December 2020: 05:58
Virtual
Carey Michael Lisse1, Jamey Szalay2, Andrew R Poppe3, Mihaly Horanyi4, Veerle J Sterken5, Charles Beichman6, Bruce Draine7, Rosine Lallement8, Anny-Chantal Levasseur-Regourd9, Michael B. Zemcov10, Ralph L McNutt Jr11 and Pontus C. Brandt11, (1)Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States, (2)Southwest Research Institute, San Antonio, TX, United States, (3)Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, United States, (4)University of Colorado, Physics Department, Boulder, CO, United States, (5)MPIK / Max-Planck-Institut für Kernphysik, Heidelberg, Germany, (6)Jet Propulsion Laboratory, Pasadena, CA, United States, (7)Princeton University, Princeton, United States, (8)Paris Observatory Meudon, GEPI, Meudon, France, (9)LATMOS/CNRS, UPMC (Sorbonne Univ.), Paris, France, (10)Rochester Institute of Technology, School of Physics & Astronomy, Rochester, NY, United States, (11)Johns Hopkins Univ/APL, Laurel, MD, United States
Abstract:
Micron sized dust grains are present throughout the heliosphere as both interplanetary dust (IPD) and interstellar dust (ISD) particles . Dust sources include grinding main belt asteroids, sputtered KBOs in the EKB, and sublimating comets throughout, while sinks include solar radiation pressure and evaporation. The full shape and structure of the solar system’s dust disks are poorly understood because we live inside of them; we especially do not understand the outer disks regions since near-Sun cometary contributions dominate near-Earth space and only 1 spacecraft, New Horizons, has ever flown a dust counter through the EKB. The ability to map the radial gradient of interplanetary dust grain composition(s) provides strong constraints on the masses and compositions of their parent relic bodies, and thus their origin and evolution in the solar system.
ISD grains from the local galactic environment continuously flow through our heliosphere after passing through the ISM–heliosphere boundary. Each ISD grain carries critical compositional information, delivering matter that may resemble the original solid building blocks of our solar system. Despite decades of observations, understanding the ISD flux and its directional variability remains an unfinished and challenging task. In-situ measurements of ISD grains from 1-1000 AU are critical to understand the flux and composition of ISD, and how the heliosphere filters and interacts with this material.
Using a dust analyzer instrument onboard an Interstellar Probe (ISP) to perform in situ dust collection as the s/c exits the solar system, we will measure the extent of the inner, near-earth zodiacal cloud and the outer second cloud sourced by the EKB. In situ sampling will inform about the cloud's run of dust particle size and composition. It will help calibrate 3D cloud models produced by remote ISP VISIR imaging, determine if the dust in the outer system is icy or rocky or both, and help solve the current disconnect between remote imaging models of ISM dust in the galaxy near the Heliosphere and ISD measurements made by the Ulysses and Cassini spacecraft. It will carry a dust analyzer for the first time ever through the heliopause, producing our first understanding of the role a dusty plasma plays in the boundary interaction regions between our habitable astrosphere and the galaxy.
