Huge gas cloud will hit Milky Way A giant cloud of hydrogen gas is racing towards a collision with the Milky Way, astronomers have announced. Dubbed "Smith's Cloud", it may set off spectacular fireworks when it smacks into our galaxy in 20-40 million years. It contains enough hydrogen to produce a million stars like our Sun, researchers believe. When it does fully interact with our galaxy, the cloud could indeed set off a new burst of star formation in the Milky Way. Details of the work, by a team at the US National Radio Astronomy Observatory and the University of Wisconsin-Whitewater, were unveiled at the 211th meeting of the American Astronomical Society in Austin, Texas.