Ok, this sounds very unlikely, but we could possibly be in a binary star system!
Paleogeologists (people who look at prehistoric strata) and paleontologists have recently discovered that every 26 million years there has been a mass extinction. These include the famous Permian extinction and the extinction of the dinosaurs. The extinctions are relatively similar, and all occur at nearly the exact time every 26 million years later. Some have been different in the way it does the destruction and the types of creatures it wipes out. eg: the mass extinction of the dinosaurs was special because all the animals that went extinct are big, cold-blooded animals (dinosaurs). Now, remember this bit for later.
When a star is made, the process usually produces a large(er) star and a smaller star. Sometimes more then two starts are made in the process but that's another discussion. It wouldn't surprise me if we did have one seeing as some 70% of all systems have multiple stars, but i wouldn't be surprised if we didn't.
When the paleontologists and other groups of scientists got together, they came to the conclusion that we could possibly have a binary star. For a long (unknown) time they searched and found what could be a binary star! A red dwarf star with possibly 2 planets. One is a gas giant four times bigger then Jupiter and the other is a terrestrial planet a bit like mercury but the size of Earth. I'm sitting on the fence with this whole idea but i really want to know where i should put my stance. I won't be religious about it and do what seems to be comfortable, but what i will do, is be rational about it.
If this is the case, then it is only 3 million years until the next mass extinction. Now i must briefly explain how the extinctions work. Every time the star comes through the solar system (out past Pluto), we as a planet experience some sort of 'change' in either our tectonic, thermal, air/water current... etc. It could also be the fact that when this star enters the Kuiper belt, it collects asteroids with it which are propelled toward Earth. But this is probably not the case all the time seeing as the chances of one hitting Earth are unlikely.
I would like you to comment your opinion on this matter.