Universe Tugged by Mysterious 'Dark Flow' Larry O'Hanlon, Discovery News Sept. 25, 2008 -- Astronomers have stumbled upon an unexplained two-million-mile-per-hour sideways shift in the universe toward a colossal, unseen, unknown gravity source beyond the horizon of the observable universe." Sweeet! Please Register or Log in to view the hidden image! What do you think this is!? Please Register or Log in to view the hidden image!