New research suggests the continuation of life on Earth depends on massive explosions on the other side of the galaxy. The explosions, gamma-ray bursts thought to occur when two stars collide, can release tons of high-energy gamma-ray radiation into space. Scientists believe they have already played a part in some the planet's extinctions. They say the blasts could be contributing to the depletion of the Earth's ozone layer. Brian Thomas, of Washburn University, in Topeka, Kansas, said: 'We find that a kind of gamma-ray burst — a short gamma-ray burst — is probably more significant than a longer gamma-ray burst....