Satellites of Our Galaxy

     Our galaxy has a number of smaller neighbors, which are believed to be satellites of our galaxy. Some of them may "orbit" our galaxy for some time, but eventually, gravitational interactions between our galaxy and the various satellites will distort their structure, tear them to pieces, and cause those pieces to be absorbed by our galaxy. In fact, there are a number of star streams in the outlying portions of our galaxy which are believed to be satellite galaxies which are in the process of being absorbed. Such galactic "cannibalism" is thought to be the way in which galaxies grow, and the long-term fate of our own galaxy may well be a cataclysmic collision with the closest large galaxy, M31, in which each galaxy is torn to pieces, and becomes part of the galaxy which results from those pieces combining to form a new, still larger structure.

     The largest satellites of our galaxy are easily visible with the naked eye in southern skies, as apparently detached regions of the Milky Way. They are called the Magellanic Clouds, after Ferdinand Magellan, who noted them during his circumnavigation of the globe, in the mid 1500's. All other satellites are too small and too faint to be seen without a telescope, and in most cases, are difficult to distinguish from the star fields within our galaxy even with a telescope.