Gary Prezeau of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., describes the results of his theoretical model that goes some way to explain how streams of dark matter particles may interact with our planet's gravitational field. "A (dark matter) stream can be much larger than the solar system itself, and there are many different streams crisscrossing our galactic neighborhood," said Prézeau in a JPL press release. "When gravity interacts with the cold dark matter gas during galaxy formation, all particles within a stream continue traveling at the same velocity." As these streams begin to interact with a planet, according to...