Dark matter in cosmological terms is matter that is inferred to exist from gravitational effects on visible matter and background radiation, but is undetectable by emitted or scattered electromagnetic radiation. Its existence was hypothesized to account for discrepancies between measurements of the mass of galaxies, clusters of galaxies and the entire universe made through dynamical and general relativistic means, and measurements based on the mass of the visible luminous matter these objects contain: stars and the gas and dust of the interstellar and intergalactic media. It is very mysterious stuff that cannot be seen, seems to exist and has a profound effect on the universe,. Cosmologists have come up with a new way to solve their problems as to what and why it is. They are inviting scientists, including those from totally unrelated fields, to participate in a grand competition. The idea is to spur outside interest in one of cosmology’s trickiest problems — measuring the invisible dark matter and dark energy that permeate our universe. The results will help in the development of new space missions, designed to answer fundamental questions about the history and fate of our universe.