Stars may alter comet paths into hitting Earth: ESA
Around 19-24 stars would come close enough to the Sun in the next million years to alter comet trajectories, sending them towards Earth, a study by the European Space Agency predicts. While the outermost planet Neptune orbits the Sun at 30 Sun-Earth distances, a star 'Gliese 710' is predicted to pass by about 16,000 Earth-Sun distances within 1.3 million years.