The Ursa Minor Dwarf is one of the faintest and most diffuse satellite galaxies of the Milky Way, lying around 206,000 light-years away in the constellation Ursa Minor. Discovered by Albert Wilson in 1954 on photographic plates from the Palomar Sky Survey, it is a spheroidal dwarf galaxy with virtually no ongoing star formation and an ancient stellar population estimated at over 10 billion years old. Despite its faintness, it is one of the most dark-matter-dominated objects known — its stars move far too fast for the visible mass alone to hold them together.