From the BBC yesterday: Alien star system buzzed the Sun 70,000 years ago. Actually it was two stars and they passed between the Sun and the Oort Cloud. Edited correction: They passed through or near the outer edge of the Oort Cloud. There's been a theory in the past that something might disturb the Oort Cloud from time to time sending a slew of comets toward the Sun (with target Earth in the way). Nemesis Star (for those of you who don't know what it is) I can't wait to hear more about these passing stars and wonder how many other significant events in the solar system are also discovered if this changes what we are looking for out there in our neighborhood.