Our galaxy is on a collision course with its nearest neighbour, Andromeda,
and the head-on crash is expected in four billion years, the US space agency
NASA said on Thursday.
Astronomers have long theorised that a clash of these galaxy titans was on the way, though it was
unknown how severe it might be, or when, with guesses ranging from three to six billion years.
But years of "extraordinarily precise observations" from NASA's Hubble Space telescope tracking the
motion of the Andromeda galaxy "remove any doubt that it is destined to collide and merge with the Milky Way,"
NASA said in a statement.
This image shows a stage in the predicted merger between our Milky Way and the Andromeda galaxy. Photo: Nasa