Back in the mid 1960s, NASA launched three very large satellites to study micrometeorite impact probability in LEO. I saw one of these satellites on display at the Alabama Space & Rocket Center many years ago. It was called Pegasus. The satellite had very large panels similar to solar arrays that were used for the impact detection.

http://www.friends-partners.ru/partners/mwade/craft/pegasus.htm

It was determined that the probability of impact varied by the size of the micrometeorite. I remember seeing a graph in one of my military space handbooks that showed the relationship. For a two week long mission, the probability of impact on an Apollo sized object was 100% for very small (dust specks) particles. The Pi dropped to almost zero for an object a meter in diameter.

Spacecraft operating in geosynch are going to get hit by dust sized particles practically on a daily basis. The engineers who design these spacecraft have to ensure this dust doesn't do any harm. The old silicon solar panels used in the 1980s typically degraded about 3% per year, partially due to the harsh radiation effects but perhaps also due to impact abrasion. Other sensitive components like Earth and star sensors have to be protected as well.