Scientific Colloquium
November 7,  2003


The Sagittarius dwarf galaxy is currently being shredded by the Milky Way's gravity, and tossing its stars across the Galaxy.  Recent detection of a "Ring of Stars" around the Galaxy suggests there might be a second such galaxy in the process of being disbursed.  These mergers "caught in the act" help teach us how galaxies like our galaxy, and by implication all galaxies, form.  The tidal debris will be used to trace the dark matter in the Milky Way, and may even affect the experiments which are attempting to directly detect dark matter here on Earth. Whatever you learned about the structure of the Milky Way in school, well, it's probably wrong.