Astronomy Picture of the Day . ... Both Large and Small Magellanic Clouds , dwarf satellite galaxies of the the Milky Way, are seen near the head of the stream at the right. ... The results indicate that most of the stream's material comes from the Small Magellanic Cloud. The Magellanic Stream is likely the result of gravitational tidal interactions between the two dwarf galaxies some 2 billion years ago, the Small Magellanic Cloud losing more material in the encounter because of its lower mass. ...