The Heliosphere and the Dust: Characterization of the Solar and Interstellar Neighbourhood

ended

The Sun and the surrounding heliosphere move through a low-density region in the Galaxy, which is filled with partially ionized gas and interstellar dust. While the Voyager 1 and 2 missions are currently exploring the heliosphere boundary regions that are shaped by both the Sun and by the Local Interstellar Medium (LISM), fundamental questions about our galactic neighbourhood remain unanswered: how is the structure and dynamics of the heliosphere, how does the heliosphere-LISM interaction work, and what is the nature of the LISM, including magnetic fields and contemporary interstellar dust composition, diversity, density and size distribution? In situ measurements of interstellar dust moving through the solar system provide unique ground truth information, but they have also been puzzling the community: they are not yet understood in the frame of dust dynamics simulations - related to the heliosphere properties. Also Voyager measurements at the heliosphere boundary kept surprising and challenging our views on the outer heliosphere to the very fundamental level. ASTRODUST will combine unique in situ interstellar dust observations in the solar system, with interstellar dust trajectory simulations that are coupled to a dynamic heliosphere, including its boundary regions and the ISM. ASTRODUST will build a synergy between two fields (heliosphere, dust) in order to answer fundamental questions about the dust and the heliosphere-LISM interaction. With ASTRODUST, we use a new way to explore and understand our local galactic neighbourhood. It also serves as an essential step towards understanding galaxy evolution (via the dust), how stars interact with their surroundings (astrospheres), and the history and future of the solar system on its continuous journey through the galaxy.