In 1963, an astronomy student named Gail Smith working at an observatory in the Netherlands discovered something odd-a massive cloud of gas orbiting the Milky Way galaxy.
Smith's cloud contained enough gas to make 2 million stars the size of our sun, and it was moving through space at 700,000 mph.
30 million years from now, a massive cloud of gas will collide with the Milky Way. Astronomers are studying the incoming cloud and learning more about its origin.
