A team lead by Felix Lockman from the US National Radio Observatory have discovered that a gas cloud about 11000 light years long and 2500 light years wide will collide with our galaxy, moving at 240km/s
|Smith's Cloud which is on a collision course with our galaxy over the next 20-40 million years.||The predicted position of impact of the gas cloud on the milky way.|
But there is no need to worry any time soon as it is not thought to be going to hit for 20-40 million years and it will probably hit a region about 1/4 of the way around the galaxy.
When it does hit through there will be lots of cosmic fireworks as it hits the gas in the milky way forming huge hot shockwaves triggering the creation of huge numbers of stars. But if you were living in the vicinity this would not be a major problem, however when a few million years later the largest of the stars reach the end of their lives in huge explosions known as supernovae it will probably kill any life in that region of the galaxy that may or may not be there now.