NASA's Search for Planet 9 Heats Up Via Videos Captured by the WISE Mission in the Vast Unexplored Region Between Neptune and Proxima Centauri (WATCH)

"There are just over four light-years between Neptune and Proxima Centauri, the nearest star, and much of this vast territory is unexplored," said lead researcher Marc Kuchner, an astrophysicist at NASA's Goddard Space Flight Center. "Because there's so little sunlight,...