Article Posted on : - Oct 10, 2011

Artist's illustration of a powerful gamma-ray burst, the most powerful type of explosion in the universe. Photo: Dana Berry/NASA.

WASHINGTON (BNS): Life existence on Earth depends on the massive explosions on the other side of the galaxy, a new theory suggests.

According to space.com, the explosions - gamma-ray bursts thought to occur when two stars collide - can release tons of high-energy gamma-ray radiation into space. The researchers found that such blasts could be contributing to the depletion of the Earth's ozone layer.

Researchers are also trying to connect the timing of these gamma-ray bursts to extinctions on Earth that can be dated through the fossil record.

Gamma-ray bursts come in two flavours: a longer, brighter burst and a "short-hard" burst, which lasts less than a second but seems to give off more radiation than a longer burst.

If such a burst were to happen inside the Milky Way, its effects on Earth would be much longer lasting. These bursts of radiation reach the Earth's atmosphere and cause free oxygen and nitrogen atoms to bang together, and some recombine into ozone-destroying compounds called nitrous oxides.

The short bursts may be caused by fender-benders between stars, such as dense neutron stars or black holes colliding.

The researchers were able to estimate that such stellar collisions probably happen about once every 100 million years in any given galaxy. At this rate, Earth would have been hit by several of these short-hard events over the course of its 4.5-billion-year history, it said.