This number is constantly changing as astronomers discover more using advanced telescopes and techniques. Some of the most well-known satellite galaxies include:

* The Large and Small Magellanic Clouds - these are the most prominent and easiest to observe from the Southern Hemisphere.

* Canis Major Dwarf Galaxy - located very close to the Milky Way, it's actually partially merging with our galaxy.

* Sagittarius Dwarf Spheroidal Galaxy - the closest satellite galaxy to the Milky Way, it's being torn apart by our galaxy's gravity.

The discovery of these satellite galaxies is crucial for understanding the Milky Way's formation and evolution. They provide insights into the galaxy's dark matter halo and the dynamics of galaxy interactions.