Interstellar dust measured in situ by

Interstellar dust (ISD) enters the heliosphere from the direction of its nose. It is first modulated by the heliosheath and then the inner heliosphere before it is measured by the dust detectors on board of spacecraft, for example on Ulysses. Various criteria exist to distinguish ISD from the dust of other sources, and different methods exist to determine the particle masses and impact speeds from the measurements.