Local interstellar cloud grains outside the heliopause

The dynamics of small (similar to0.01 mum) interstellar grains in the heliospheric transition region is studied using numerical simulations. The velocity distributions of the grains at the boundary of the heliosphere are found to depend sensitively on the global structure of the transition region, in particular on the presence of the heliospheric bow shock, and can be also used to estimate the charge-to-mass ratio of grains. The simulations include the grain impact velocity distributions that could be measured on board an Interstellar Probe spacecraft. Similar dust dynamics is expected around astrospheres.