The Dark Side of the Universe

Ninety-five percent of the Universe is a mystery! Astronomical observations suggest that most of the universe is “dark.” The stuff out of which we are made, the visible world we see around us, seems to comprise only 5% of the mass-energy of the Universe. An unknown dark matter holds our galaxy together and a mysterious dark energy pushes the galaxies apart. The dark side of the Universe is the frontier of 21st century cosmology.