The Astroprof’s Page takes a look at the interesting star Gliese 710, a K7 dwarf with a particular claim to distinction: it’s headed in the direction of our Sun at about 24 kilometers per second. Give it 1.4 million years and the star will have closed to within a light year of Sol, shining at a magnitude of 1.2 and disturbing the icy debris out in the Oort Cloud. A rain of comets moving into the inner system is the probable result.
Barnard’s Star is moving towards us too, closing to within four light years around 10000 AD, but we needn’t wait for a close stellar pass to start worrying about catastrophic collisions. As the battered surface of the Moon suggests, the Solar System can be a hostile place, making a space-based infrastructure to prevent future disaster an imperative.