  Emission of dust up to a few micrometer in size by impacts of sand grains
during saltation is thought to be one source of dust within the Martian
atmosphere. To study this dust fraction, we carried out laboratory impact
experiments. Small numbers of particles of about 200\textmu{}m in diameter
impacted a simulated Martian soil (bimodal \textit{Mars Global Simulant}).
Impacts occurred at angles of $\sim 18^\circ$ in vacuum with an impact speed of
$\sim 1 \rm m/s$. Ejected dust was captured on adjacent microscope slides and
the emitted particle size distribution (PSD) was found to be related to the
soil PSD. We find that the ejection of clay sized dust gets increasingly harder
the smaller these grains are. However, in spite of strong cohesive forces,
individual impacts emit dust of 1\textmu{}m and less, i.e. dust in the size
range that can be suspended in the Martian atmosphere. More generally, the
probability of ejecting dust of a given size can be characterized by a power
law in the size range between 0.5\textmu{}m and 5\textmu{}m (diameter).
