'Dark matter could send asteroids crashing into earth'

Researchers have said that dark matter could disturb orbits of comets in the outer solar system, and hurl them inward.

Theoretical physicists Lisa Randall and Matthew Reece at Harvard University, said that this phenomenon could lead to catastrophic asteroid impacts on Earth like the one that most likely led to the extinction of dinosaurs, Discovery reported.

Randall and Reese suggest that the cycle of doom closely matches the rate at which the sun passes through Milky Way's central plane, hinting that the actual culprit could be galaxy's "dark disk."

They analyzed craters more than 20km wide created in the past 250 million years, and compared their pattern against the 35-million-year cycle; they found that it was three times likelier that the craters matched the dark matter cycle than that they occurred randomly.

The findings have been published online in the journal Physical Review Letters.